Metal Chips on bottom of cooling head and ontop the piston?

[TheCyclist]

What in the world happened? I have marks up and down the walls of the engine camber and there is a residue on the top of the piston head that won't come off and has some chipping. Possible metal broke off and just ran in there?

I barely have 1 gallon through the engine and not sure if to just replace the sleeve or whole engine.

[Double G]

Pull the engine apart and you'll probably see the piston skirt broke and danced between the piston and head.
Interested to see photos of the untouched engine internals.

[TheCyclist]

I will take some photos later of the damage. Would this just require a rebuild on the sleeve and piston?

[StixXxJaTo88]

Most likely

[Assassin]

Detonation from hyper lean conditions can cause what looks like dents or chips in the head & on top of the piston. Look just like something banged around inside. Just pointing out a possibility.

[Double G]

I will take some photos later of the damage. Would this just require a rebuild on the sleeve and piston?

Not a rebuild. Replacement of the piston and sleeve along with a thorough cleaning of the block.

[TheCyclist]

Well I didn't take photos but I did replace the piston/sleeve but it still won't start but didn't have the time to heat up the block before dark. Going to try tomorrow after I have my heat gun and heat it up properly. The sleeve was really chewed up though and the crank was really brown/gritty with engine gunk. Tried to clean it but nothing came off; almost looked like rust but the engine is only two weeks old.

[Assassin]

Wish you had photos of it. Are you pre-heating the engine with a heat gun? I had a bud with a 1 gallon F4.6 from the 2011 X with some serious internal damage that was unusual. Around the transfer and boost port it looked like blow by was going all around between the sleeve and crank case. My theory is maybe when using a heat gun to pre-heat the engine, the crank case gets much hotter then the sleeve, so when its fired up the sleeve and case are not fully sealing in the ports and track causing blow by until the sleeve heats up and catches up to the case...

Its a theory, I would appreciate opinions on.

[StixXxJaTo88]

I'd second that....heat guns light my cigarette....maybe a blow dryer? If needed....I've never used anything too heat up the motor too start it, although I'm not really running in cold weather.

[mattster1971]

Did your connecting arm split down the middle and disengage from the piston? I ran too lean and it did that and then beat up the skirt of the piston. I also had discoloration that looked like rust but that is because of the extreme temps it reached.

[guardog]

+1 on mattster1971 did the same thing. I had metal chips around my piston too. cleaned it up and continued to run 2 more time until the connecting rod split. Was told I ran it too lean. engine was relatively new also. ended up putting out 115.00 for new engine. Lesson learned.... never run too lean. You always want a good steady stream of blue smoke and use a temp gun !!

[TheCyclist]

See and I always learned that and I had the HSN about 6-7 turns out. It shouldn't have been too lean....and it ran just at about 220 before i found the chips and never was above 240

[Mind_Reader7]

6-7 turns out? Holy crap, that's so rich. How did it even start?

[Assassin]

I'm thinking how did the needle not fall out... Put it to factory reset, it is indeed possible to back out the HSN so far it let's air in.

6 turns out shouldn't even be attempted, that engine has had a hard life with that kind of crazy tuning. I feel bad for the con rod.

[TheCyclist]

Put it back to 4 turns out and still won't keep running and replace fuel lines today but keeps cutting out

[Assassin]

Could you take some video, maybe things are getting lost in translation.

[Mind_Reader7]

I think you need to clean your carb out.

[TheCyclist]

Will take some this evening for you all. Thanks for all the help! I cleaned out the carb as well, I am so frustrated that I might just replace it but honestly I ran it rich for the premise that this wouldn't happen but it did anyways =\

[Kyleb]

See and I always learned that and I had the HSN about 6-7 turns out. It shouldn't have been too lean....and it ran just at about 220 before i found the chips and never was above 240

Mine ran the same way


Check out this thread
http://traxxas.com/forums/showthread...bees-of-tuning

[guardog]

Yup. My con rod split down the middle, metal flakes etc... Only a gallon through it. Was told I was to lean but I don't think i was. Always had good solid blue smoke. No warranty either. Just broke in my third new one.... And last one