Break In done breaking in yesterday... drove like maniac today!! Help



engine trouble

just a tip, these are not high performance engines and they should never be ran full throtle. If you want it to last you should not drive over 5000 rpm or so.


My throttle has only two settings, idle and full throttle. I ride at nothing but full throttle with NO problems. A decent two stroke should easily hit 10,000 rpm but ours are limited by modest port timing and lack of a reed valve :-(

Woods, check for airleaks. If no airleaks, pull the jug and take a peak. If piston is not scuffed and jug is ok, replace the rings and try again. Sounds like you may have run your engine lean and overheated it. Running full throttle wasn't your problem, running it too lean may have been.


I won't tell you that was an expensive lesson. You weren't anywhere near being broken in.

Does it start up, O.K.?
How does it feel when turning it over slowly?
You could have put a hurtin' on any of a number of internal components.

I doubt you did anything to the rings, unless you broke one, but you'd see that. Scuffed piston? Look at the exhaust side closely. (look for marks or discoloration on the skirt, below the rings) Cylinder wall? Once again, look very closely. (verticle marks, discoloring, it doesn't take much)

You may have warped the jug (made it out of round) or head.
How does the compression feel compared to "new"?



yes there are scuff marks..... but not at all deep just marks... I have my carb pin set on the second one down, slot two. Should I move this down to the 3rd on the next engine? It still starts and runs.. about 10 mile an hour. No leaks... used wd40 to check for leaks... does it mean it is broke?
Im not too worried the guy said send it back for a new one since its under 30 days...


A couple of things- "light scuffing" is all it takes sometimes....

Now, I don't know who you got the engine from, or how they'll handle it, but consider yourself lucky if they replace it under warranty, especially if they read here that you beat the crap out of it (I believe the tech term here would be "improper break-in proceedure") after just two tanks of gas. That was way too early to run it that hard really.

What mix ratio/brand of oil did you use for break-in?


speaking of crazy RPM's the main problem behind crazy RPM's is the heat right?

And it can melt copper at those temps on the engine? I am not sure but can it?


Not sure what you mean there....heat will not cause crazy rpm's, but crazy rpm's will cause a lot of heat, so will running it really hard before it's broken in.

No, you can't get one hot enough to melt copper. (1900F)