i think he said earlier that he let it warm up befoe pushin it. I think he needs to do another leakdown. never got an answer on what kind of leak down test he did.
piston locks up
- Thread starter airwave
- Start date
i think he said earlier that he let it warm up befoe pushin it. I think he needs to do another leakdown. never got an answer on what kind of leak down test he did.
i have performed many leak dn test on 2 strokes and this is not an air leak,and i do warm the bike up properly before hittin it. i have never installed a big bore kit on a 2 stroker so this is new to me, the heat expansion makes alota sense sicivicdude you hit it on the head but what can be done to aleveate the problem, i can ride for hours but if ya go wot for more than say 45 secs builds to much heat. it has done this three times, i know it is damageing the sleeve but to tear it down with out knowing how to remedy is senseless. im gonna ride it till its done but on next rebuild i want to know this will not happen again. is there a fix
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With all due respect to you and all the other guys, Airwave, if you are warming this up and running for hours just fine and then WOT kills it, then heat and expansion probably aren't the problem. Instead you must be breaking the oil film, i.e. running lean at WOT.
What I've gotten from reading this thread:
a) You haven't done a leakdown test on this motor.
b) You think it isn't lean but haven't really done a WOT plug chop.
If I'm wrong, please correct me. My point though is it sounds like you are assuming some things, and you and I both know where that gets you. All the times I've ever run in circles for awhile it was because I "knew" some things that ended up not being true. Bear in mind that any airleak you might have should be at its worst when the engine is pulling its hardest.
What I've gotten from reading this thread:
a) You haven't done a leakdown test on this motor.
b) You think it isn't lean but haven't really done a WOT plug chop.
If I'm wrong, please correct me. My point though is it sounds like you are assuming some things, and you and I both know where that gets you. All the times I've ever run in circles for awhile it was because I "knew" some things that ended up not being true. Bear in mind that any airleak you might have should be at its worst when the engine is pulling its hardest.
checklist time lol
cause of lock up/seizure:
1 - no lubrication or breakdown of lubrication
2 - piston temperature is too high due to lean mixture due to air leak or small main jet
3 - piston cylinder clearance is too small ( a gasket kit is 15$, hone it and use the same piston for as long as it lasts if you like)
4 - no oil in gearbox and bearings/gears seize and let go with heat build up
really, you need to take the top end off.. because without looking at it, its hard to be COMPLETELY sure what it was.. hate to be the bringer of bad news, its going to need to come apart soon anyway.. but thats just me!
cause of lock up/seizure:
1 - no lubrication or breakdown of lubrication
2 - piston temperature is too high due to lean mixture due to air leak or small main jet
3 - piston cylinder clearance is too small ( a gasket kit is 15$, hone it and use the same piston for as long as it lasts if you like)
4 - no oil in gearbox and bearings/gears seize and let go with heat build up
really, you need to take the top end off.. because without looking at it, its hard to be COMPLETELY sure what it was.. hate to be the bringer of bad news, its going to need to come apart soon anyway.. but thats just me!
little-j and royalt67 sound right to me. you said you did the leakdown so that would have to lead to either not enough clearance or lean jetting at wot. if you can't do a wot plug chop bc it seizes you should probably up the jet size before trying. or just pull the jug and check the clearance so you don't seize it again. if your clearance is ok then it has to be an airleak or jetting. no other explination that comes to my mind.
