Rebuilding the King Motor after slamming a wall

Bandit2013

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80
After getting the King Motor 305 Deluxe wild orange, I had plans on rebuilding the vehicle from the start. Since I was used to the 2 speed transmissions on my 1/10 scale nitro cars I wanted similar with this one. When I ordered the KM002-305wo, AKA KSRC-002 30.5cc, I had also ordered all of the hop up parts to rebuild it. Had some difficulty getting the 30.5cc engine started so I bought a Rovan 36CC engine to replace it. Figured I would dig into the issue with the 30.5cc engine sooner or later (turn out the ignition coil was too far away from the flywheel so no spart or very weak spark when using the pull start. I did get it started with a cordless drill and socket but that was not ideal.

Below is the final assembly with all the aftermarket parts installed. Had this thing dialed in and ready for some yard bashing. Went over to a friend's home for Thanksgiving, he was interested in this hobby, so I took the KM and the Ex Barca with me to run in his back yard. I got a good feel for the yard with the Barca first. Was time to get the KM warmed up and ripping. A few laps to warm everything up and was a bit heavy on the throttle coming out of a wide turn, honestly thought I was going to clear the neighbor's solid wooden fence, nope. First thing I saw was the left front wheel flying up in the air, followed by the KM. Sure, the initial impact was severe enough to rip the front section of the frame off, the entire vehicle when airborne and took a hard hit as it tumbled on the ground several feet away. This is what the vehicle looked like before I left my home.

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Here is the aftermath of the incident. Sort of glad I brought up two vehicles as the Barca served up the entertainment before dinner.

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The damage is not as bad as it looks. It is obvious the front chassis needs replacement. At first, the damage looked as if it included more components than anticipated. All I could locate were some extended control arms. Why not? New shocks, sure, get some bigger ones. I had planned on reusing the bulk of parts on the rebuild but after separating the rear from the front end, I noticed the rear wheels were not moving as they should. Turns out that the brake mount dug into the back side of the main gear plate. Removed that and noted the bearing on the inside of the bell housing was toast. It still rotated well but the rubber seal was no more. Using an unvented bell housing assembly has its faults. The clutch was in good shape.

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Got the parts in for the front end. I could not find the front upper bulkhead part by itself and bought a new set. The front half of the vehicle is mainly Rovan parts. Opted for the Taylor HD hinge pin brace set to complete the front end. This build will also include the stainless-steel reinforcement plate on the front end in hopes to prevent chassis separation. Perhaps this will keep the kick up area from weakening over time, doubt it will prevent damage on impact at full speed into a tree, wall, post or other immovable object.

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I got the hardened frame. I hope this will not make the material more brittle. To my surprise, I did not have to drill out the holes to mount the SS plate. At this time, I did not mount the aluminum skid plate as I need to make a mod to the tab thickness so it will fit. I would not be able to install the plastic skid plate as there would be no tab left to hook in the square hole after modifications.

A few more images of rebuild. The parts from the wreck that are still good and parts that cannot be reused. Since I sort of when overboard on the rebuild, when I am done with it, the only parts I will reuse from the wreck is the engine, fuel tank, and servo/receiver assembly. I will build up another vehicle with the leftover parts, just need another frame, fuel tank and a few more minor components. Tearing down the separated portion of the front end was a bit difficult due to some bent parts, damaged screws and such. Shocks were still good, shock tower and shock brace still straight. Control arms and front turn knuckles were good, bearings in good shape too. I may be able to get the threaded bolt of the sheared off ball end out of the steering control arm. The servo saver did its job well. I would assume that the weaker turn buckles also helped to protect the steering servo from damage.

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Up next will be the new rear end assembly.
 

Bandit2013

Well-Known Member
Messages
80
Now for the back end. Sorry I did not take pictures during the process as that would have provided a better story. Here is the bulk of text and the pictures will follow.

Since I was changing the length of the control arms, I felt compelled to go even further. I could have just reused the parts from the original build but wanted to try some other brand of components. To start off with, I had replaced the gear plate and bell cover assembly on the limited-edition Rovan 360B with a Turtle Racing HD V2 complete clutch system from DDM. Also decided on the Black Magic 18/56 gear set. I was impressed with the response of the gear set more so than the 2 speed King motor assembly. The plan was to get the same for the rebuild. It will be a heavy vehicle, may need a larger engine but for now the 36cc will do fine.

I got the mod bug while shopping for parts. Detroit Performance RC had most of the parts of interest. I still wanted to use the novelty exhaust and roll cage but was unsure if the better alternates would work out. For something different I decided on the RCMAX rear bulkhead components along with the rear bumper brace, shock tower supports, transmission brace and a Diablo shock tower/brace. Taylor left and right engine braces, fuel tank brace, V2 gear box, and already had the rear hinge pin braces. I also got the RCMAX rear hubs but could not use them. Axles fit fine but the hole for the axle pin did not work with the Baja wheel hubs. If I had the larger axle pin, I could have used the 5ive-t wheel hub (Rovan equivalent) as there was no issue with hole alignment. If and when I do an outlaw build, I will make use of that. I also got the Red Arrow front steering knuckles that would not fit with the Rovan extended arm ball end. Bummer. I would assume they are compatible with the Red Arrow extended control arm kit. One other part that did not work out was the aluminum Modified RC spur gear cover. The Turtle Racing gear plate was too thick. I can modify that easy enough but for now the stock plastic spur gear cover fit without any issues.

I was hoping to avoid the issues I had encountered when I rebuild the King motor from the start. There was some difficulty with mating parts to some extent which was corrected with the proper assembly procedure (keep the screws loose during assembly and tighten ones that would be difficult to get to first. Since I am using a novelty exhaust system, fitment with the Rovan rear bumper brace was an issue. Had to grind that down for clearance. The good news about the RCMAX and Taylor parts, no mods needed with one exception, gear box.

The gear box front section when assembled fit the differential perfectly. I first tried the Rovan differential with the cast aluminum housing. The rear half of the gear box did not fit. Had to remove some material from the inside surface of the flange that provided the interference fit with the bearings. Yep, already tried to press the bearings further on the differential. I did have a rebuild set I got from Detroit Performance RC when I ordered the parts but the bearings for the diff were thicker than the one's on the new differential assembly. I doubt I would have any better luck with a different differential brand, when comparing the mating surfaces of the front half of the gear box to the rear half, the inner surface of the flanges did not match. I was able to correct this issue but ran into another problem, I got the diff assembly with the oversized cups, way too big for the extended drive shafts. Found an alternate differential housing but that also had issues but easy to correct. It fit the case but would not rotate due to extruded area where the set screws were located. Sanded the boss down at an angle for clearance and was able to retain the set screws. Now came the next challenge, fitting the Taylor gear box loaded with stuff into the Modified RC rear plate. I got it to fit once but after I took it out to swap out the differential it would not go back in again. Easy fix, slight material removal with a file did the trick. Still tight to get in but got it into place where in needs to be.

The other part that required modification was the Turtle racing bell housing enclosure. I could have opted for the racing version that does not enclose the bell completely. The diameter of the disc brakes interfered with the housing, no clearance. If I had a machine shop at my disposal, this would be an easy task. I had to grind the part down by hand using a cutting wheel on a Dremel tool. I did this before when I installed the same assembly on the other vehicle. I knew what and where to cut. Now the bell housing is vented at the disc brake area.

The rest was just assembly without any mods. The exhaust and roll cage fit without any issue. Rear bumper assembly from the wreck was used. The RCMAX rear bumper brace did not require any changes, plenty of clearance for the exhaust pipe. The Diablo shock tower brace fit like a charm around the roll cage. I was going to use the Rovan brace, but it did not line up with the mounting holes properly. The King Motor shock tower brace required some material removement to fit around the roll cage and the rear bumper brace needed to be ground down where the interference fit to the exhaust pipe occurred. Not so with the RCMAX parts. All went together without a hitch other than what was mentioned earlier.

Now for the pictures:
Partial assembly without engine. Testing for fitment of parts. I did not have the RCMAX Diablo shock tower brace at this point, so the rear shocks were not installed. In case you were wondering what that white matt is, it is from a roll of gasket material used to make ventilation dampers. I have two layers placed on the table separated between a throw blanket. This white stuff is great as it is chemical resistance and difficult to damage. I also used it to line the aluminum battery box to protect the battery from damage. Used for assembly only and not where I would do any grinding, drilling or anything that would result in damage to the table.

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While waiting for the last few parts to arrive, I installed the outerwears cover on the bottom of the engine. Bummer that the velcro adhesives were poor. Could not get it to stick to the aluminum. Even tried cleaning with acetone, tried heat on the adhesive. nothing. Time to innovate and make use of some high temp RTV sealant to stick the velcro strips to the aluminum. If that did not work, was going to move to plan B and use some aluminum screen material that I have samples of I got from work. the mesh was too fine for use in HVAC applications but will work with this.

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Another view of the front end. Completed with bumper installed. This was on the original car as an upgrade but did some damage to it after jumping a speed bump in the parking lot at work, car took some major air then landed on the front bumper getting embedded into the pavement. Before taking vacation, I took the bumper to the machine shop and milled off the damage. It probably will not stay that way for long.

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Bottom rear view of the Modified RC rear chassis plate. The Rovan rear bumper assembly with bashing scars intact.

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Trying to figure out how to get the outerwears cover to fit the bottom section of the engine. Some of the old parts in view that will be reused in another build. Not shown in the picture was the Taylor cooling clutch plate. I took this picture before installing it. That was much easier to do than expected.

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I did have an aluminum easy start installed when I wrecked the vehicle. I was surprised how well that kept the grass out of the engine. That kit was meant for a smaller engine that has the extended tabs on the flywheel. The adapter bolt is extended so there is an additional spacer used to offset the starter. Since my plan to reuse the King Motor 30.5cc engine with the salvaged parts, the easy start kit was a perfect unit for that. The Taylor pull start unit was attractive and the small vent holes in the housing was of interest. Also, it did not stick out as far as the Rovan easy pull starter assembly.

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After the RCMAX rear bumper brace and Taylor Diablo Rear shock tower arrived, I was able to complete the assembly. No mods needed. The red hex spacers are used to compress the roll cage inward for ease of fitment. The Diablo brace clears the roll cage. I did have to look at the Diablo exhaust systems available. Eventually may get something in that line up. For now, the novelty exhaust is fine.

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I also wanted a different look than the wild orange body. That one was modified to fit the 2 speed transmission. Thought black, red and orange in a different design would be cool. I was never any good at painting bodies, have done many in the past but never worked out as intended. To be honest, I ran the car more without the body installed. The other car I ran with the body on it. It will still collect the grass clippings and other debris regardless of body or not.

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Bottom of chassis. I hope I do not see this side too many times when bashing unless it is due to taking some air off a hill and not due to a roll over. 20211221_083905.jpg

Time to clean up the mess. I will leave the table cover in place so I can start rebuilding the salvage King motor. I got carried away with something different. Can I make it better? not sure. However, one thing is for certain, it did not lose any weight in the process.

Here is where it all began, right out of the box, all original. Looks like I need to add the weight of the body as it was not on the car when I weighed it. 20lbs 12.6 oz, 30.5cc engine.
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Converting from plastic to aluminum parts, with body this time. 30.5cc engine. 2 speed trans. Battery box/servo unit was plastic. The weight penalty for modifications was 7 lbs.

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Different chassis material, stainless-steel front brace, 36cc engine and everything added has made this one a porker. Different exhaust as well. 30lbs 14oz. Add 5 lbs for the wheels and wonder why the car is so slow off the line. I am only doing this for fun, and not serious about racing. Time for a bigger engine?

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Just for smiles and grins, I got the full weights of both vehicles with wheels. The Blue Rovan limited edition 360B weighs in at 38lbs, 1.6 oz. The rebuilt one on the right with mixed parts was not as heavy but damn close to call it a draw at 38lbs, 1.4 oz. Both have the Rovan aluminum wheels. The rebuilt one would weigh more if I added the rear wing. Tires are different but wheel foams are the same. The new build does sit a little taller than the one with stock arms. If you push down on both, the one with the extended arms is one inch wider. The only actual components that remain from the King Motor 305 would be the gear cover, tires (excluding rims and foams), fuel tank and the King motor prefilter. I do have one more task, adding functional lights. Waiting on the control module (simple type for on/off control only). I do have a Killer RC module but could not invert the rear taillights. Brake light would get bright with throttle applied and dim with brakes applied. I guess I could reprogram the servo since I am using the AFGRC. Not sure if I can set the reversal that way. Much easier just to invert with the transmitter. Have to wait for the rain to stop so I can get a first run on the rebuilt. It is more of a new construction than a rebuilt as things went in a different direction. When the parts arrive for the salvaged parts (chassis and a few minor parts) I will post that here. Having a third Baja adds to the fun. Still plan on getting a Losi or Vekta. Still undecided on that choice. May end up with both eventually.

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Bandit2013

Well-Known Member
Messages
80
First run of the rebuild was good but not awesome. Should have replaced the clutch during the rebuild. When the car starts to run slower and slower and then barely moving is a good sign the clutch surfaces or clutch spring is out. Yep, pads were worn, and spring was elongated. It is the original clutch that came on the engine. Figured it was due.

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Ordered a few more parts to improve performance. New brakes so I do not have to worry about brake failure. Turns out that it was not the aluminum fan that sits between the two rotors was the reason for issue I had with the Rovan. It was the aluminum brake nut. Could be there is some interference with the turtle racing clutch housing as it was a tight fit even after grinding down on the housing to improve clearances. Brake nut basically rounded off closer to the spur gear which allowed the brake rotor to slip off the nut along with the aluminum fan part, that ended up with a bent assembly. Easy fix with new parts.

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This set has not made it onto the project vehicle yet. I did install the other brake set on the aluminum Rovan baja. Had to make some adjust the linkage to get them to work. So far they are doing the job. Now I need to replace the clutch on that car as well.


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I had an extra clutch, 7000 RPM to try out. That actually worked out great with the 18/56 gear set. Also got my order for Maxima Castor927. It looks like mango pee but does seem to work out well. At least I can see the smoke now. The synthetic 2 stroke oils that I could find locally were formulated for no smoke and probably full of additives. Not much to find locally except for Lucas semisynthetic 2 stroke. Never thought distilled castor bean oil would be something of value. I was able to run a tank of the castor oil. Reminds me of the Nitro fuel smell.

After correcting the spark issue on the King Motor 30.5 engine, I will use it in the restoration of the vehicle. The sticky on the velco did not seem to stick to the aluminum engine case. Some of it was dried out when I installed the outerwears underside cover on the 36cc engine. Found the black RTV sealant works really well and should hold up with the heat. Here is an image of the 30.5 getting its velcro glued on.

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Most of the salvaged parts are in great shape from the wreck. A few parts for the front end were needed but most of the parts were still good for reuse. I tore down the rear completely and rebuilt it. KM Differential was in great shape, No issues with any of the gears or bearings. Once the RTV sealant cures I can get the outerwears cover installed and engine mounted onto the rear chassis. No rush on this as I am still waiting for some parts. Had to order most of the components from TIT racing which has wearhouses in US/Canada and other parts from China. Instead of the pad printed KM or RFC logos, it has the TIT logo. The front chassis plate was ordered from Rovan. Fuel tank is coming from China from TIT racing. I have no desires to use the aluminum fuel tank. I would consider the welded one found on Detroit Performance RC or DDM but that is expensive. The others that are CNC alloy use rubber gaskets or rubber paste seals which may be ok first off but will probably leak after a while.

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I did buy the hubs for Rovan LT/ Losi 5iveT as I intended to use them on my Exceed Barca but did not have the 5mm pins. Was not aware there was a difference. As it turns out, the RCMAX rear hubs will not fit with the Baja 5B hub types. Had to order a few drills to open up the pin hole on the axle. Nitride 5mm drill bits should do the trick. May need to do this at work as I do not have a vice at my disposal. Will see how that works out with hand tools first. Baja nuts will not fit the LT/5IVE-t hubs but I have that covered. Baja wheels will fit if you have the correct wheel nuts. Already checked for clearance fit. As it turns out, while running the new build and during the tuning process I slammed the rear of the car into the brick steps. Had a mental block and instead of hitting the brakes I hit the throttle by mistake and when I realized what I did, tried to correct for the mistake and slammed the rear. That busted the upper tie rod end and twisted the control arm. Now I will have an extra one for stupid mistakes as they can only be purchased as a set. Thus, the reason of bringing up the RCMAX rear hubs. I did not use them due to fitment issue with the axle and baja hub assembly. Now that I know the trick, I can make use of them. The parts from the rear will be extras for the other two vehicles that have the multi-part carrier assembly. This hobby is a money pit. Still having fun but want to run more than rebuild. Soon to have three Baja vehicles.
 

Bandit2013

Well-Known Member
Messages
80
While I was posting the last update on the salvage, some of my parts came in. I am surprised they did not ring the doorbell and run like they normally do. Uhm, that is not orange. Perhaps those doing the anodizing for Rovan are color blind. I guess it is sort of on the orange hue but more red than orange. No big deal really as most of the other parts are not orange like the King Motor original aluminum parts. Hint: that automotive "Purple Power" degreaser will remove anodizing from aluminum. I had used it to clean up the parts before reassembly, including the aluminum hear box. Guess it depends on how the part was anodized or if it has a clear coat over it. Another thing about this replacement chassis is it also had the holes pre-drilled for the reinforcement stainless steel plate. Don't mind the mess, I was looking for the engine spacer and pulled all of the parts out to find it. Dumb ass me decided to place it with parts for the other vehicles. As for the unassembled front bulkhead, I have it there to keep the alignment of the steel plate before using loctite on the bolts closer to where the radio and servos mount. Added some lock washers and the red stuff.

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Here is one place to use the loctite red 271, on the screws that secure the front chassis to the rear. Since it a bit thinner with less solids than the blue stuff, I was a bit liberal using it but not by choice. It will keep the two plates together even if the screws come out. Before adding the loctite to any of the bolts, I had pre-assembled it first. Tightened up and verified chassis was straight. Removed one screw at a time, applied loctite and re-inserted the screw. Repeated for the remaining screws except for the 4 in the front bulkhead. Need a few more parts to complete the front end so when they arrive, I will only use the blue 272 stuff.

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I learned my lesson, for now every Baja build I do will get the reinforcement plate. However, it is a bitch to grind down the square hook on the skid plate. The plastic skid plate cannot be modified unless you cut off the hook. You still have the two front screws securing the front of the bulkhead and the two that secure it to the bumper part. Some may not like the added weight of the stainless-steel plate, it is heavy, but prevents the kick up area from breaking off on impact or due to flex during extended use. The weak point is where the two bulkhead screws mount towards the bend. I am new to the 1/5 scale scene so perhaps others may have similar or different experiences. I am not expecting this to be a light-weight build. I will find out soon enough how well the 30.5cc King motor engine will hold up. The lower casting of the engine has King Motor embossed on it. Not a cut but more of an extruded lettering. Not sure who makes this engine. Zenoah clone of sorts as it has similar clutch parts.

Would I have rebuilt this if it was still stock? Absolutely!
 

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Bandit2013

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The Zenoah G320RC with 34cc stroker mod arrived the other day. This will be the engine I plan to use on the so-called rebuild project. Was considering the Taylor 35 but can wait and see how things progress with that first. I was able to transfer the RCMAX pull start onto the Zenoah. At least I did not need to add spacers as this was required to be used with the Rovan 36cc engine due to difference in flywheel. I was not aware the RCMAX parts would work but they did without any issues. Also got the outerwears on the pull start to keep the dirt out.

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The acetone was used to prep the surfaces after cleaning with other chemicals (throttle body cleaner). It was in the house. Bought from Walmart for cleaning printed circuit boards in my guitar amps (aluminum tube/valve holders on the preamp tubes tend to shed aluminum dust that falls onto the PCB, a Q-tip swab dipped in acetone works. Isopropyl alcohol is mostly watered down and does not dry easily).

Since the rebuild project turned into build two from one deal, my focus has been on the new build more so than the rebuild.
I am considering removing the Rovan parts on the front assembly (bulkhead components) and swap them with the Taylor RC components. Nothing wrong with the Rovan parts as they seem durable enough and will make use of them as spares for the other Rovan vehicle, including the half inch extended arms. I already twisted one in the rear due to my negligence. Have replacement parts for that already.

Any body have experience with Red Arrow? I found the control arms on the Detroit Performance RC shop. They are extended but no mention of how long they are relative to stock length. I did make an inquiry with DPRC but have not gotten a response (it was late so I may have some response later today). Already have the Red Arrow HD steering knuckles and want to make use of them. They did not fit with the Rovan style of control arms as the ball joint assembly was too wide. Red Arrow use the chrome molly ball ends so those would be much stronger and do not have the weak points as you get with the Rovan / King Motor control arm ball joint assembly.

https://www.detroitperformancerc.com/product-page/red-arrow-usa-hd-v2-baja-extended-arm-kit

The control arms I had on the KM when I wrecked it did hold up to the abuse prior to impact with wall. They are still good to reuse with some minor blemishes. The Rovan ball ends can break easily vs the KM one's as they are different designs (reference to the aluminum alloy components, never ran with the plastic parts). One would think the white plastic bearings used in the control arms and with the ball ends would be ok. Not always, they can loosen up the assembly too much.

To complete the rear end assembly, I will be using the Taylor RC rear hub carriers. I did not use them at first after I discovered the Baja axles and hubs did not fit the Taylor hub carriers due to width. I did have a set of Losi hubs that would work but not with the wheels I intend to use. Did find some adapters that will do the job. All I have to do is drill out the 4mm hole for the 5mm pin. Nitride drills already in the house for that task.

Have not made much progress with the King Motor rebuild, still waiting on some parts to arrive. It seems the USPS tracking indicated package arrived in NC but now is in FL. WTF? I live in NC not FL. so why route it there first? That would explain why the tracking stated delays in estimated arrival. Bummer. Oh well, no rush.
 

Bandit2013

Well-Known Member
Messages
80
I did have some fun with the new build project for a short while. While tuning the hi needle screw I slammed the rear end into the brick steps. Did an oops by pulling the throttle back instead of hitting the brakes. Not sure why I had a brain fart for that one moment. I am used to running gas/nitro cars as I have done so since 1986. I guess I wanted to keep going but did manage to turn the wheel to prevent another front end disaster. This time, car slid sideways into the brick steps causing impact on the left rear wheel. That resulted in breakage of the long set screw used for the tie rod end and ball joint. The control arm also twisted, and the rear hub assembly went out of whack. Had to get another set but was able to buy the rear end parts vs the total kit. At least the rear hub part with the bearings and perhaps the shim could be used on the wreck rebuild. The hub carrier is bent to hell. If I end up destroying this one, I will go for the FLM extended control arm kit.

Since I was replacing the one rear lower control arm, I took the liberty to change the rear hub assembly. The parts I was waiting for that are adapters for a Losi to HPI conversion with a 1/2 inch extension came in: DarkSoul axle extenders for Losi 5IVE, purchased from DDM. Also got some 5mm pins and the proper drills to drill out the axles. I needed the parts in order to use the RCMAX rear hub carriers since the offset on the Rovan hex hubs (I would assume HPI would be similar) would not permit the 4mm pin to be inserted. RCMAX hub rear hub carriers are thicker, could be due to the larger bearings. Drilled, installed with pin pressed in (tight fit, probably do not heed the screw in the axle to keep them in but installed it anyways as well as the rubber o-rings.
20220115_204033.jpg Had to use nitride drill to open up the pin hole since it is hardened steel. That drill cut into the steel like butter. The 5mm pin did require pressing into place with a vice used as the press. I did not buy any reems to open up the hole for improved pin clearance. Since the Baja is rear wheel drive, I have a spare hub set if I had to repeat this process again. The threaded shaft is a bit longer than the HPI (including the clones) hub so I will not be able to use closed end wheel nuts.
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I do have reservations on the alloy ball joint assembly that uses tiny screws and thin materials. They can break on you without notice. Perhaps it is just the Rovan part as I have not been able to break the King motor part. They are different designs. Below is the Rovan front upper ball joint that could not take the abuse. Could have just been a defect from the start or poor design in general. I have not broken any rear ball joints yet even the ones I had on the new build project when I twisted the rear end. The steel screw broke first, and the ball end is just fine. Just wanted to make a point.

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Now that the rear end is complete/repaired, I can get to the task of Rovan 36cc engine removal and prep for the Zenoah-ESP G340RC stroker.

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I also decided to replace the fuel tank with a vented version. I can use the take-off for the wreck rebuild project. At least the new tank uses a felt clunk-filter like the one supplied with the Zenoah engine.
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I will say this now. It was a PITA (pain in the arse) to get the velcro strips on to the Zenoah. Even when using the RTV sealant trick did not make for an easy task. Had to cut the strips into short pieces to attach to the clutch case. Got it done.

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I did order the correct engine for the Baja. I double checked it to confirm: BB128C. It was not an easy fit. Some may want to say it is a Rovan chassis, no wonder you have issues. Not for this project. Complete rear chassis is made of RCMAX/Taylor and Modified RC parts. The Rovan 36cc engine was an easy fit. The King Motor engine spacer could not be used as it was too tall. Had to improvise and use a steel spacer I grabbed at work thinking it may be useful. It was. The King motor engine spacer measured 9.6mm (0.378"). The alternate spacer I used measured 7.62mm (0.300"). That change in height allowed for proper alignment of the engine to the clutch bell assembly with gear plate attached. I could have ground down the engine spacer, I would have done so if I did not have an alternate. It did take a few love taps with a rod and hammer to get the top rear support seated properly. Did this with the screws loose. Checked for issues with the gears and such, all good. Ready to roll once I break it in.

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Also decided to take this opportunity to install working lights. I did get a higher capacity battery (Venom 5000mAhr) but it would not fit into the aluminum battery box. If you look at the spec it is actually a 4300mAhr battery. At least it did fit into the Rovan plastic battery box, so it was not a waste of money. Need that for the wreck rebuild.

I hope to have the electrical completed so I can at least get in a few heat cycles on the engine. No point in running today as it is raining.
 

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Bandit2013

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Messages
80
I got around to installing working lights on the new build. Pictures attached show the sequence. All off, top plate + tail lights, buggy pods, all lights. There is a flashing mode and a seizure mode before you get to all off. I should have no issue seeing this thing when it starts to get dark out at sunset. Will not need to use them in the summer but in late fall, winter, and early spring they will be helpful. Still have one thing to do before I fire up the Zenoah is to address the one tie rod on the rear end. It is too long and needs to be cut to length for better camber adjustments. One of these days I will get the dining room to acceptable order. At the moment I have two projects going so it is a bit of a clutter. Nobody here to complain except for me. Also, when I have company over for our jam sessions, no place to eat dinner. I play guitar, bass and drums but not at the same time. I usually man the drum set and let the other two musicians decide if they want to play guitar or bass. My friends used to call my house the music store, now they refer to it as the garage. It is all good.
 

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Bandit2013

Well-Known Member
Messages
80
I still have that one.... also getting rebuilt but with same or similar parts. Waiting on the components. I opted for the single parts vs the full kit so it will take longer to get.

The wall was a 2 for one deal.
 

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Bandit2013

Well-Known Member
Messages
80
I got to that point of installing the King Motor 30.5cc engine on the wreck rebuild. All was fine at first then noticed I forgot to install the kill switch. Actually, there was no switch on the engine at all, planned on a take-off from the 36cc engine that was on this vehicle. Oops. Also noticed the long layshaft had a bend in it. The rear mounting plate also has a lot of flex to it. Something did not seem right. Need to tear it down and replace the back plate and address the other issues. It was apparent that more damage had occurred to the transfer of energy on impact of the wall. There was some other damage I did not expect, the fan housing was cracked at one of the mounting ears to secure fan plate to engine. This was not apparent until I removed the fan cover to gain access to the kill switch assembly. Since I am waiting on imported parts to arrive, may as well make the wreck a bit stronger than it was before I slammed the wall.

At least I have an extra 2speed set. Wanted to use that on the Rovan but decided to keep it single speed.

As for the rear chassis plate: Checked Rovan website, $52 for the thicker plate, 6mm with some pockets milled out. Nothing special, made from Rovan mystery metal. Detroit Performance RC has the Modified RC upgraded rear chassis plate for $59, 0.25" or 6.35mm with stated aluminum alloy used. Guess which one I decided on. Hint, it was not the Rovan part. Not trying to say one product is better than the other, just one is unclear as to its materials. I do have the Modified RC plate but a different version on the "build my own Baja" that was spawned from this disaster. Not sure I want to pick up the pieces after the rear assembly sh!ts the bed. That may be part of the fun but also takes the fun out of it if it fails in less run time vs build time.
 

Bandit2013

Well-Known Member
Messages
80
Made a decision to pull it apart to replace the layshaft. There was enough wobble on the shaft end to cause gear mesh issues. At least I did not loctite any of the screws holding the rear assembly together since I left everything loose for engine install. This also keeps the parts free to get good alignment of the gear plate and clutch housing.
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As for the gear box, yeah, I did loctite all of the screws. I used blue stuff so it should not be that difficult to take apart. However, the rear chassis plate was secured with the red stuff. That will require heat. Never noticed how flimsy the rear chassis plate was until I proceeded to install the engine. At first, I thought the movement was just the loose rear assembly. It was to some extent but the bow I was seeing was in the plate. Once all of the engine supports are attached the rear chassis does get some reinforcement. I would prefer something a little stronger than the thin metal sheet. Thickness of original rear chassis plate is 3.91mm (0.154 in). New part will be 6.39mm (0.250 in) thick. I plan to use the sacrificial plastic skid plate with this rebuild.

Since the engine fan cover was cracked on the 36cc engine, I can imagine there was some displacement that occurred on impact. I am surprised there was almost a 1/16 in displacement at the end of the shaft. (1.6mm if you only understand metric). Not sure what the displacement tolerance on the gear mesh would be. No need to go that deep. Hopefully the other shaft in the extra 2-speed kit is straight. The bend could have been there from the start but doubt it. That would have been noticed from the start. When I installed the 2 speed, the gear mesh was near perfection. I did not notice any wobble or gear mesh issues.

Sometimes parts will not be as they seem when reusing them from a hard hit. Nothing else appeared to be bent. Shocks on the front end and rear are in good shape. It is what it is.
 

Bandit2013

Well-Known Member
Messages
80
Swapping out the layshaft was not difficult but it was messy. Already cleaned out the gear box some time ago but did not realize the layshaft was bent. The old shaft is easy to tell apart from the new one. I did check the new part for straightness before I took the transmission apart.

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Since the inner case was flooded with grease, I used a Q-tip cut in half and shoved it into the threaded hole to keep the grease out of it so I can secure the screw onto the pin with loctite. Also replace the C clip with a new one. The old one was the original clip that I bent when removing it the first time. That sucker went flying across the room and almost took out the glass door in the China cabinet. Probably a bad idea using the dining room as a work area.


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Easy if you have done this before. All buttoned up and ready to install on the new rear chassis plate when it comes in. Now have to heat up the chassis bolts to get them out. Much easier to do when there is nothing in the way.

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Interesting to note, the differential and drive cups are the originals. I am surprised there is no wear on the edges. The drive axles were worn to the point of replacement. Soon to get this thing completed. Still waiting on parts to arrive. Passed customs and they are in the states.
 

Bandit2013

Well-Known Member
Messages
80
It took about 40 minutes to remove the rear chassis plate. I was liberal with the red loctite during assembly as I did not expect to be removing it anytime soon. After seeing how flexible the rear chassis plate was, did not want to have to replace that after it breaks. Uncertain of its integrity considering how much abuse the vehicle endured prior to the wall incident. Due to the size of the parts and amount of heat sinking the aluminum will provide to the screws, it required considerable amount of heat exposure to soften up the loctite. Had to do this job out in the garage on a small workbench. Also had to wear gloves to prevent getting burned.

After I removed the rear chassis plate, it seems strong enough when trying to bend it by hand. The screws were tight and there was no movement in the rear and front chassis joint, I looked at that before disassembly.

When the new part comes in, I will get some weights to compare stock to the Modified RC. I am just curious to see what the weight difference is.

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