King Motors X2 RTR 30.5cc

[nitrocat]

For all you guys that still run your King Motors X2 what parts would you recommend to change prior to even breaking the motor in? And then after break-in what would you guys recommend to change or replace with aftermarket/ Losi parts? And with what motor would you guys recommend getting from KM to start with? Or would you guys recommend a roller?

Any help would be greatly appreciated.

As I am making the jump to 1/5 scale I have done my research for 9 months now. And will decide what to by in a week.

Thank you.
JGK

A Losi is the best upgrade right out of the box you can do [emoji457]

 

[crankestein]

http://vid948.photobucket.com/albums/ad330/mazpr2025/Mobile Uploads/20160323_101047_zpso8gllnpd.mp4To continue the quality control issues...

And for those who think I did not tore it apart and verify every corner of the truck... here is the storybook Photobucket.

http://s948.photobucket.com/user/mazpr2025/King Motor RC X2 4WD/story

After barely one tank, and service the diff/spur gear, binding signs;
http://vid948.photobucket.com/albums/ad330/mazpr2025/RC/King Motor RC X2 4WD/20151219_000259_zpsovpwzyxu.mp4

More story photos, some after the Mayhem;
http://s948.photobucket.com/user/mazpr2025/RC/King Motor RC X2 4WD/story

 

[crankestein]

Received some parts, decided to give Rovan and King Motor the benefit of the doubt, but once againa quality control issues on new parts delivered.

Defective front drive shaft, pin does not fit at all. Its off easily by 1mm.

Part number: 151047
Rovan King Motor (same seller) front drive shaft

Check out attached video.
http://vid948.photobucket.com/albums/ad330/mazpr2025/Mobile Uploads/20160324_083925_zpsha2mjeqq.mp4

 

[Magnum500sw]

Anyone want to sell their "junk" truck ? I'm in the market.

 

[crankestein]

Post on WTB section.

Good luck

Here are a few more to keep you motivated on the purchase.

Rovan 21T lasted half a tank.

Once again, Rovan KM front shaft pin broke.

Rovan 21T engine mounts did not fit, had to sand the edges to finally make them work.

Small clip at idle, rebuilt motor.
https://www.dropbox.com/s/hmcktlam8hein3e/X2 30.5cc King Motor 305 Rovan.mp4?dl=0

Issues with package rtr sold by King Mitors;
- fancy aluminum air filter comes loose even w provided o ring and red threadlock. Filter housing looks fancy but its junk, besides, KM / Rovan does not sell replacement filters!!!? You got to buy the whole unit if replacing them.
That cap falling off cost me a brand new top end. I was able to re use the full crank.

The solution, a rubber piece from a MTB tire wrapped around it and to be safe, none of that crappy outer wears, an old thick sock damped in filter oil wrapped around the housing. I can drive it through clouds of dust and dirt at WOT back to back until I get tired, jeje, and the internals stay clean silver shinny.
I carry a few cut out old socks prepped w oil and replace every tank or so.

Following is a YT video of someone exactly experience the same issues as me, 3 blown differentials. Remedy: Losi internals

 

[Magnum500sw]

I just figured some angry owners would be glad to sell some of their junk 1/5's that's all.

 

[crankestein]

No worries, if I do decide to sell, you will be the first person I will tell.

This guy nailed it, exactly what I am talking about. Not a bad company, but be aware of what you are getting into.

 

[Emrah Ozturk]

how is KM-X2 DELUXE? With full alu parts, is it better than Losi 5ive?

 

[warracer]

For all you guys that still run your King Motors X2 what parts would you recommend to change prior to even breaking the motor in? And then after break-in what would you guys recommend to change or replace with aftermarket/ Losi parts? And with what motor would you guys recommend getting from KM to start with? Or would you guys recommend a roller?

Any help would be greatly appreciated.

As I am making the jump to 1/5 scale I have done my research for 9 months now. And will decide what to by in a week.

Thank you.
JGK

Get losi internal diff gear set X3 (15$ each)
Aluminum intake manifold (20$ or so)
get some spare pullstart (18$ each)
Spur gear mesh plate (35$)
spare 19T losi pinion (20$)
HPI Baja air filter or better ( I went with TGN mushroom)
Fail Safe (beerc or dynamite)

I got a roller w/ upgrades + KM 30.5 for one hell of a deal (thanks Dan or whoever sold it to me at KM)
the km30.5 4bolt works flawlessly for me, no issue with 15L through it so far.
I race at a local club and I never felt I needed a Losi 5ive so far...

Honestly , all the only issues I got were rear diff locking up (internal failing) , pinion going bye bye (no mesh plate) and pullstart
And all these issue aside from the internals are the same on a brand new losi 5ive...

BUT, I do believe racing is less stress on the drivetrain (loose dirt) than heavy bashing in grass for example... That could explain the exploded diffs in this thread... but im just throwing ideas...

 

[crankestein]

Thats exactly what I did, aluminum carb manifold, losi diff internals F/C/R including the shims, wire mesh the flywheel fin openings (with JB Weld).

For the carburetor filter, throw away the metal flower design filter, and get a stock Losi filter. If you do decide to stick with the metal one that comes with it, use electric tape, and an old sock over it tighten it making two ears/ or using zip ties. I sometimes use two old socks, the inner one with some oil. The flower type filter will come loose under vibration, regardless if you use locktite. Thats what happened to me, bunch of dirt got inside while bashing and destroyed the engine, combined with the badly shimmed diffs, and cheap plastic manifold, was a disaster. I know all engines come with the plastic manifold, oh well, it broke on mine. Swapped the rear shock spring with heavier ones. The muffler mount is a pain, ended zip tie and using rubber grommets to hold it in place. I placed a metal clamp/or use a zip tie, over the muffle rubber mount for more durability, the wider zip tie the better to cover more area. One area that needs attention, the bolts for the ignition coil, locktite them, one gets busy on the truck, and forgets about those bolts hidden under the metal black plate. On mine, one got loose and destroyed the flywheel fins and almost the ignition coil.

Must say I took it out for a spin today and ran three full tanks, taking a break every 25 minutes to cool off the diffs and shafts. The truck is holding well, still using stock servos, radio, receiver. Did a few jumps about 4 feet in the air, easy to control and predicable in the landing, had a few misses landing nose or tail, still running strong.

*Other things you need to buy, front drive shaft, a spare set of wheel nuts, nothing I hate the most than ruin a day of bashing for a lost wheel nut. Nothing against KM store, but whenever you do replace parts try to stay with Losi.

Its not a bad truck, lets say I had a lemon (although check the video, same thing happened to him, that is not me), lesson learned, I know the in and outs of it, and can most times can tell right away whats wrong with it.

The 30.5cc engine is not the baddest fastest engine in the neighborhood. It is very reliable as long as a clean filter is used, synthetic 2 stroke oil with fresh fuel. Things that I did, took apart the engine and inspected for any burrs or sharp edges. Had a minor issue with one of the engines, but got my money back, it happens, these are mass produced weed eater engines, not racing at all, same as pocket rocket piston port or reed engines.

 

[crankestein]

Full circle with the X2 (yes, Losi 5ive clone, and now some so called 30 Degree North DTT).

Last week had some crazy bashing, packed about 10 pounds of mud. Cleaned it up good, opened the engine, overhauled center diff, tuning, etc.

Had some turnbuckles laying around from a 1/8 nitro buggy, and went on to make some diy braces.

- Replaced center diff cups for Team Chase
- Replaced center diff oil, 100K weight
- Installed a Losi 5B spark plug protector
- CNC servo mounts


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Final thoughts;

The truck feels much smoother, no binding. Its not a significant power increase, but I do notice a difference in the acceleration, it is more predictable. Yes it is plastic ball ends, in case there is a crash it bends and snaps, instead of breaking parts. The throttle servo flex is gone, the center diff does not sway front to back or side to side. Already ran two tanks, and parts holding on well.

 

[crankestein]

Received the Losi front shock shafts.

I am a little disappointed, Losi brand is a downgrade compared to the King Motor X2 shafts. KM nor Rvan sells them separately and thats another fail.

Uploaded some shots side by side;

KM on the left, significant thicker thread and nylon lock nut.
Losi on the right, definitely the weak link on the front shafts.
Who would have thought, KM shafts should be an upgrade to Losi shocks, lol, but they are nowhere to be found as replacement shafts, not Aliexpress, Ebay, BG, GB, Asiatees, and so on...

Yes, its a direct fit, the Losi shafts are the same diameter and length, pistons fit as long as Losi shafts are used. W minor modification piston to shaft can be both used either way.

Update: The KM bottom section of the shaft is not threaded. I have never seen that before, and it was a pain to remove. Ended cutting the ball end and be done w it. Swapped both sides, little lighter oil and two extra holes from the 4 it already has.



Cheers

 

[crankestein]

Here is the X2, shows some contrast as the custom made mud guards are new shiny black, the window grill mint silver and everything else is bashed from today's session.

Need to cut the shell mounts, they protrude and pick up too much mud.

Moving toward a more rough look for now. Possibly get the blue shell from 30 Degree North, but not sure and maybe just pasti-dip all black.

 

[crankestein]

Here is a short clip postedon YT of the King Motor X2 also known 305...

 

[crankestein]

The best upgrade so far is the DDM Dominator pipe and some port work to the cylinder head and piston.
The clone X2 tuned pipe is way too restrictive for the 30.5cc engine. I dare to say the Dominator pipe is still a bottle neck as I can tell the engine wants to spike up for more power and there is not enough flow. After the wrist pin swap, put a new ring, broke it in exactly like OBR recommends, port work, 360 Dom pipe (which was a pain to install), and now running a few tanks.

With the X2 pipe and the port work the engine was too loud, no tuning would make it rev up, good torque but that was it. Spark plug too dark regardless of tune. With the Dom pipe now the plug us lighter and engine is waking up w a more predictable power band. The sound difference is night and day, before was offensive loud, after the pipe swap is almost identical to a 80cc two stroke dirt bike, or pocket rocket w the distinctive raspy sound.


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Had to install a spring into the plug cable, way too close and at one point it burned a little on the rubber, now is protected.

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[crankestein]

I should create a thread called "what did you break today?"

Nice Sunday weather, a little windy, but on the bashing location there are tons of trees which block the wind very well. Decided to go a little leaner 30:1 w the ported top end and new pipe, engine ran crisper, and overall more consistent power. On my second tank and all of a sudden I thought the clutch gave out, was I so wrong...
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I had checked the clutch about a week and a half ago, bolt and nut, washer and threadlock.

 

[crankestein]

I had to remove the DIY turnbuckle I had made from the center diff to the clutchbell carrier because the new pipe took that bolt. Did not last two tanks of jumps without the turnbuckle brace.

This is how it stands as of now...

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Anybody who does not know will value as scrap metal on how it looks, but its all dirt. I drive the RC hard, not stumbling and doing 40 feet jumps into a flat surface. Mine are no shelf queen, they take a beating, upgrade as I break them. Next on the list is a Vertigo clutch carrier and diff brace. I already have the clutch bell with clutch 19T pinion gear. Luckily I had also a center spur gear. It looks worst than it is. I should do a complete teardown, lets see, center diff was done about a month ago. Have not serviced the front and rear for about 8 months, its about that time. Still have the Zenoah G290 in the box, will replace once this engine dies, does not seem anytime soon, pulls strong and idles forever.