Flooded the King Motor 30.5cc yesterday (not what you are thinking)

[Bandit2013]

All was working out just fine breaking in the KM30.5cc engine. Charged up the receiver battery and brought in the KM Baja to work. Wanted to take advantage of the nice weather while it was still daylight at the end of the workday. Got it fired up. A few laps around the access road where I park to warm it up.

I should have walked up to the area where I planned to run it first before going nuts on the throttle. I could still see the Baja from where I was standing, so thought it was ok. Since the property slopes downward in that area, the ground level was not fully visible from my point of view. Once I saw the huge splash of water and lost sight of the Baja, I realized the fun was over. I was not aware of this deep cut out area at the end of the property. It was not there a month ago. Sort of a low-cost retention pond thing. I did not expect any standing water, let alone a recently dug trench full of it.

Not sure I got all of the water out of the engine. Both inner and outer filters were soaked. Rung them out to what looked like a full cup of coffee spilled on the garage floor. Compressed air did come in handy. Will have to dump the fuel and invert the car with the spark plug removed.

 

[BCRstudio]

Even with compressed air. I would also spray whole engine with WD-40. Toss the air filter.
But good thing you blew engine off with the air, right away. (as well internals)..

EDIT:: yeah, the wd-40 spray over is just extra protection. until you get new air filter element. (unless you have a spare).
Otherwise, you can pass on the spraying engine down (waiting for filter) and just do as you stated, new fuel (make sure all lines are cleared prior)
And with new filter, get it up and running ASAP for at least a few minutes. And that should be enough for block to heat up, and dissipate any water trapped in roller bearings, etc..

 

[Bandit2013]

The filter was fine, just washed last night and re-oiled it this morning.

I did do a quick tear down with it. After removing all of the surface water, I did use some throttle body cleaner (did not have WD-40 available), compressed air and such and added some oil into the spark plug hole (not very much, just a few drops, sort of what one does with the Nitro engines). I was able to get it started on the bench without the filter. Let it run to warm up. All seemed ok last night.

Had it running today. Working great until the clutch blew out. Actually, thought it caught on fire due to the amount of smoke. The transmission and bell are moving smoothly. No binding. It is possible I blew out an engine seal. I will find out soon enough. Engine was making some odd rattling noises. If the engine is toast, no big deal. The engine was a part take-off from the start. I only decided to use it when I rebuilt the KM as I felt the Rovan 36cc was lacking.

 

[Mick Boomer]

As long as you got all the water out quickly and cleaned-oiled the air filter and fuel tank It’ll be ok. Let it eat. Guessing your 25/1 theres a lot of oil and especially after you start it again it will blow whats left out.
However, expect damage because of the sediment in pond water. You’re probably gonna deal with premature wear. Its a rovan though lol. Get a g320

 

[BCRstudio]

It is very possible (not sure if you cleaned clutch shoes, with air, etc..) That when you used carb cleaner (with shoes being slightly wet-from water).
The shoes would have glazed over, and trapping that carb cleaner in the wet shoes (even running the next day).
That heat build up, with the glaze, would have been enough to ignite.

Assuming the carb cleaner had acetone, or the like in it. Would be flammable even months, once dried into those shoes.

I use to (well, actually had Yacht restoration business) paint yachts, and we would wipe bare aluminum down with shop rags.
If we/me Let the rag(s) dry without soaking in water first, even months later you (as we did) could put a cigarette out even next to a month old dried out rag and boom it would combust on the spot.
Denatured alcohol, lacquer thinner, mineral spirits = No problem. But acetone will stay (due to fast evaporation rate) for MONTHS....

But nice to hear you got it up and running.
I think you stated in op, that you were breaking engine in? So no, I do not think seals would have worn..
But I would have to go back and reread your op, to see if that was the case. Seals will not wear down, from break in time.
Now the fire could have burnt oil seals (so now, I would say = Yes do a tear down and check everything.)

 

[Bandit2013]

I only saw lots of smoke flowing out of the vents I cut in the bell housing. Smell of burnt rubber. I did not use a liberal amount of carb cleaner. Gumout carb cleaner (acetone and toluene). Only used that in the carb with throttle plate open. Turned the flywheel a few times, followed with compressed air and then a few drops of oil. Doubt any of this got onto the clutch. I am sure that the water got into the clutch assembly.

As for the break-in on the KM30.5 engine, I never used it from the original assembly as I had issues getting it started. Busted the pull start and both arms destined to get it going. Bought a Rovan 36cc engine (did not realize it was a lame duck), did a plastic to alloy conversion with a 2 speed trans and then slammed it into a wall (see my avatar). Got the bright idea I could build two Bajas with the parts I had but things went in a different direction. When I rebuilt the King Motor, I decided to use the 30.5cc engine since it was just an easy fix (ignition coil). I was on the second tank of fuel before sending it into the pond.

I will get to the removal of the gear plate to see what is going on with the clutch. It is overheating. I would not doubt that the hot clutch getting flooded with cold water resulted in some damage to the spring or clutch pads. That may explain the odd noise I am hearing after the dunk. Ruled out the brake discs as the noise is present with full brakes applied.

 

[Bandit2013]

Removal of the gear plate was not as a pain as I remember. Must be thinking of the Turtle Racing HD V2 clutch assembly I have on the other two Bajas. The gear plate and clutch bell assembly I have on the King Motor is this one: https://www.rovanrc.com/product-rv85317

Clutch looks good. Did not see any issues here. Shoes are the same thickness as a new one. I did push some compressed air in the holes than I drilled in the gear plate. Not much if any dust came out. I did not see any signs of an engine seal leak. Clutch bell was dry as were the other parts. I would assume if there was a seal leak it would be covered in oil.



There did seem to be a repeat of the issue I discovered with the Rovan gear/clutch assembly when I tore down this vehicle after slamming the wall. The brake hex was beginning to rub against the gear plate. I will have to clean up that area of burs and may polish up the brake hex as it is galled up. Also found the lay shaft bearing slipped out against the 2nd gear shift plate. I could not get the aluminum spacer as it was too thick. Could be the 7075RC brake hex which made assembly different.

I am using this brake hex on all of my Bajas.
https://www.detroitperformancerc.com/product-page/7075rc-upgraded-brake-hex-for-baja

Looks like I will need to add some shims to keep things in their place. There was plenty of clearance when I assembled it, I did not expect the layshaft to shift outward as it did. When this assembly is heated up, it becomes difficult to move the vehicle. Reason for the burning clutch and lack of performance (car would literally slow down as if I had the brakes working against the engine.) After I removed the gear plate, I did check for any rotational resistance on the layshaft. Rotation appears to be fine with the transmission without any notable resistance. Diff also appears to be working well. At least I can try to make some corrections to prevent this issue from getting worse.



A point of reference on the old assembly that was on this vehicle when I was running the 36cc engine. I am surprised that due to the amount of galling and blown bearing on the clutch bell that it was not bogging the engine down. There was not much left of the bake hex either. I did have 2nd gear dialed in as well as the shifter was installed correctly. It was working fine in spite of the mechanical issues discovered after slamming into the wall.


The other thing that was noticed, the shifter plate was mounted backwards. This is not the first time I made this mistake. I thought it was on correctly since it did shift into 2nd gear on the bench test. It was not shifting under load. Well damn, this King Motor 30.5 just running the 17/57 gears is great. Just wonder what will happen once it gets onto the 22/52. Very competitive to the ESP-Zenoah G340RC running the 18/56 gears. A few things to do before I close it up and get it running again. This time I hope to install the shifter in the proper orientation. That may also be contributing to the extra load on the engine and clutch. Still think the bearing shift on the layshaft and interference of the brake hex is the main contributor.

 

[Bandit2013]

I did pull the clutch and clutch mount just for kicks. The rear side of the clutch mount was suspicious looking. Almost looks like there may be a leak on the seal.





I did clean up the back side of the gear plate. Buffed out the area that was galled up.


I had a few other clutches on hand. Since I was not using the Rovan 36cc engine anymore, the RCMAX clutch cooler got installed on the KM30.5cc engine. Installed new clutch and tried to reassemble the rest of the parts. No way this was going to work. Would have to start the car off the ground and drop it. Tried the other clutches even without the rear washers. Nope. Installed the original clutch mount and that worked with the original clutch assembly.





Got outside in time to get a good warm up run in. All seemed good. 2nd gear was kicking in but then it bogged down. 2nd gear was not letting go. Could not even roll the Baja with the engine off. Smoked the hell out of the clutch too. However, once I cold everything off with some compressed air, still binding. Rolled it backwards a bit and it was free to rotate forwards.

Time to make a change. Ditch the 2 speed and go back to single speed. Have to order some parts since I used the original layshaft. I am also going to ditch the Rovan gear plate and clutch housing. I still have the take-off parts from the Rovan LE when I converted to the Turtle racing HD V2 clutch setup. Before the parts come in, I guess I could reverse the shifter and tighten up the release spring and see if the low gear by itself presents the same issue. I do want to check if the brake hex has gouged out the backside of the gear plate. At least I bought a few of the gear sets from DDM (black magic) and I have the 57 sized spur gear. That should mate up to the pinion already on the open clutch housing. If the issue presents itself after disabling the 2nd gear, it could be something else, like a seal leak once the engine gets up to operating temperature. I would think I would smell fuel and not burning rubber.

 

[Bandit2013]

As a last resort, I could add a dye to the fuel that will glow under UV light. I do have a UVA flashlight I use to inspect for conformal coatings. I will have to see if any of the 2 stroke oils I have will respond with UV light. If the seal is leaking, I would assume the dye would be present in that area. I believe this is more of a binding issue than seal leak.

 

[BCRstudio]

Most dyes (mineral based) will work fine for that. Granted, I do not think that is the issue. (seal I mean), however, even with your good pictures, I can not say for sure (as I do not have engine in hand). Best of luck.

When I say mineral based, I mean dyes for AC/heating (most sure work). I have a bottle here, but they are pretty cheap, and a drop goes a long way.

 

[Bandit2013]

Have all the parts to ditch the 2 speed. Once I removed the decked gears it was easy to see one of the contributing issues. Layshaft was warped. The one-way bearings are installed correctly. No issue there. All of the parts move as they should when cold and or disassembled. One thing to point out, the transmission cover will get very hot when running the car. I had this issue with it before slamming the wall. This layshaft warping may have been the cause of that incident (was in a wide full throttle turn to the left but car suddenly shifted to the right and hit the wall like a magnet.

Removed the gear/clutch bell plate. Yep. the brake hex was digging in. I had it shimmed this time.



The clutch bell moves freely. No binding issues or play in the bearings that I can tell. I am not going to bother to take it apart as at this time, not going to reuse this setup.


Since I have to replace the layshaft, was a good opportunity to check for loose screws in the differential. This one is practically new. Very smooth movement on the output shafts. Before I split the case, the drive train was easy to rotate. No binding issues.


Perhaps the one-way bearings are not rated for the RPM range. The extended layshaft is prone to warping. Gear mesh issues and full lockup when 2nd gear is engaged. It was not just the clutch that was smoking, the transmission case was too hot to touch without getting burned. Just not worth the headache. Another Novelty thing. I never had any issues with the two speeds in the 1/10 scale platform. Still have the two. Hard to believe they are 22+ years old.

Time to move on. Get the new parts on the car (including a new clutch). Charge the receiver battery, fuel up and let it rip. See if the clutch gets smoked again. That should fix at least one problem. Will have to see if this corrects the chirping noise that became apparent after the water bath in the makeshift retention pond.

 

[BCRstudio]

Yeah, I am not sure there is ANY well made 2 speed (or 3) for 1/5 and 1/4 scale.
I agree, with 1/8 and smaller, I have never had an issue with a 2 speed (other than constant adjustment, per track/clay/off-road/on-road/etc.)

Ditch the 2 speed is IMHO, if you want speed, go with a lighter (more break points) and ditch some of the unneeded alloy parts.
I have many scales, to make sure what parts will cause more weight (hence, I will need to setup car for a better 50/50 weight distribution)
But most of my cars I do not bash, and much more about speed, or grip (on tracks).
On a open field, now that is a different story (and yes, I have cars for that as well).

Anyhow, looks like you are heading in the right direction. Keep up the great work.
Love the pics BTW. And all the updates
(shims were a good call), may help (1 or 2 degree in temps).

 

[Bandit2013]

Not trying to turn this into a build log. Lesson learned, stay out of the water. I am sure clutch and transmission issue would have presented itself sooner or later. The 2 speed did work for a short time. Not a reliable setup and not worth the money.

Had a few other parts I bought from DDM racing a while back. At least the gear cover fit. Had trouble using it with the Turtle racing HD V2 assembly I have on the other vehicle. Open clutch bell carrier from the Rovan (take off part) Plastic rear plate support (original part). Had to settle on using the DDM Black magic 56 spur with the Rovan 17 pinion. I could not get the DDM Black magic 57 spur to mesh properly. Had this issue with the match black magic set 17/57. Could not use that pinion since it is for the Turtle racing HD assembly. the 56/17 is not a full mesh but it appears to be a little over 50% overlap with the teeth.





Also had to make a decision on the brake discs. The carbon fiber fan did not fit due to thickness. The offset of the layshaft for the brake hex may be suited for the stock brake hex. The 7075RC brake hex is something I prefer to use. I did ponder the thought on using three brake discs. I will find out if it is one of those, "do not do this" sort of thing. The better stuff, RCR brakes, I have on the other vehicles. I did not feel like harvesting them for use on this rebuilt project. If the three disc becomes a blunder, I will opt for something better. Not like I plan on competing with this. It is just a yard thatcher or weed puller. General purpose bashing fun.

 

[Bandit2013]

That did the trick. Had a good 30 minutes of run time. No heavy white smoke from the clutch. Had to cut it short when I lost one of the screws in the steering linkage. At least I have resolved the issue. Damn, did not realize just how fast this one was. The 17/56 gear setup worked great. The 2 speed was holding it back some. Glad I ditched it.