Engine Trouble Uh Oh!!!

Discussion in '2-Stroke Engines' started by SRPM, May 27, 2015.

  1. SRPM

    SRPM Member

    Removed my head today cuz I heard a noise and found this pitting. Any ideas couldn't find anything in the combustion chamber.
     

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    Last edited: May 27, 2015

  2. jaguar

    jaguar Well-Known Member

    maybe it was like that new.
    looks like ding marks instead of pitting. are marks on the piston also?
     
  3. crassius

    crassius Well-Known Member

    little round marks like that are almost always caused by bottom end needles coming out - stop running it & use the good parts as spares for your new motor

    EDIT: disregard this if that head came off a different motor at some point
     
  4. SRPM

    SRPM Member

    No was not like that new. This is very recent. It looks like pitting and dings. Almost looks like the metal was bubbling. Yes piston too but it looks more like dings on it.
    Bottom end bearings? The ones connecting piston and connecting rod at bottom, cuz I check and there's no play or anything. Or the bearings on the shaft for the magneto and spline gear?
     
  5. crassius

    crassius Well-Known Member

    both the big end of rod & small end use tiny roller bearings - the rollers for these look like small needles & come out pretty often

    when they start coming out, the engine is no good anymore - running it again will leave you with a lot of broken stuff that is unusable - stopping now may save the piston & cylinder for use as spares
     
  6. SRPM

    SRPM Member

    Yah I saw and have heard that. So that was the first thing I checked but nothing seems bad, no play in it or anything and also couldn't find any other signs that would point to that. Also wouldn't I be able to locate the pin that came out or would it hide out in the ports or something?
     
  7. SRPM

    SRPM Member

    Oh wouldn't there be pitting all over the combustion camber instead of just in that one area if that were the case too? And recommendations on replacement engine, maybe something with better build quality etc. etc. And not too expensive. This is my only transportation at the moment.
     
  8. SRPM

    SRPM Member

    Is this what I need to fix it do I need less or more? Are those the right bearings for the crankshaft the one connecting to the magneto and spline gear and are those the correct seals. Please let me know soon so I can order. Thank in advance.
     

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  9. crassius

    crassius Well-Known Member

    it could have gone out the exhaust - also, it could have been an extra that fell in at the factory

    not all that hard to take out the piston & check the top of the rod to see if one is missing (hard to tell from the pic, but top rollers are smaller than bottom & the pits look small)

    once apart, you may be able to tell if ALL pieces are gone (these sometimes get cut in half by piston passing a port) and whether you want to fix it a bit & try again
     
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  10. crassius

    crassius Well-Known Member

    you won't know what's needed till it comes apart - few folks are up to the job of replacing a rod, so many just buy the whole crank

    you may not need main bearings until you look at them, also, there are diff types of main bearings
     
  11. SRPM

    SRPM Member

    Thanks for reply so quick. I just need to rebuild to get me around until I get order a new engine would that get me started? Is it ok to pull the piston out of the jug and pit it back in again Or will it mess up the seating of the rings?
     
  12. SRPM

    SRPM Member

    Ok I looked and on the engine I got it says 202 crankcase bearings is the crankshaft bearings or clutch shaft bearings. They only have a choice between two bearings the other. is sealed both ends. And with the parts I'm try to cover everything that could be bad once I can open it up completely, so do I have all my bases covered?
     
  13. SRPM

    SRPM Member

    Opened her up and found no pin missing, so now what?
     
  14. SRPM

    SRPM Member

    I failed to mention there's play in the crankshaft bearings I can wiggle connecting rod and fly wheels and everything moves up down side to side. The up down is more on the magneto side and the side to side play is less dramatic and seems kinda ok . Could pieces from those bearings make it to the combustion chamber?
     
  15. crassius

    crassius Well-Known Member

    I'm not sure what your bearing uses for the cage around the individual balls. Could be that cage is riveted with small rivets that would leave the same mark as the needles. Either way, if the crank goes up/down, that bearing is bad.

    If that bearing is same as drive shaft bearing, then it should have one side of the seal pulled off. You'll need to read info here and prepare to do real work to get that bearing out & new one in. There is a set of pics here for step-by-step engine tear down.
     
  16. SRPM

    SRPM Member

    Ordered a build your own engine kit, just have to wait for it now. Thanks for all the help. I've have my fair share of bearing removal experience and they are a pain in the a**
     
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