Finch Posted October 1, 2013 Report Share Posted October 1, 2013 +1 for carnage pics.Do a leak down and pull the head.If ya dont know anything about a leak down test go tot he tech section good instructions there. Quote Link to comment Share on other sites More sharing options...
joey83 Posted October 2, 2013 Report Share Posted October 2, 2013 Lean out = Too much air and not enough fuel. Engine runs extreeeeemely hot and melts down top end. I have seen this happen in neutral. My friend had a dirtbike that the throttle cable was idling engine really high and melted it down. Quote Link to comment Share on other sites More sharing options...
J-Madd Posted October 2, 2013 Report Share Posted October 2, 2013 I've seen so many alky motors (not mine) lean hang for a long time to the point you think they're gonna explode and not have damage. This was with Nicasil plated cylinders though. They didn't know to hold the throttle wide open to kill it. Quote Link to comment Share on other sites More sharing options...
joey83 Posted October 2, 2013 Report Share Posted October 2, 2013 This was a KX 250 with plated cyl. He said he started it and it was idling really high and he had been having problems with throttle cable. so instead of killing it he started messing with the kink in throttle cable for 30-40 secs and it died. tried to kick it and had no compression. I bought it from him like that and rebuilt it and have clocked 10 hours on it since. How long do those alky motors hang up like that? Quote Link to comment Share on other sites More sharing options...
Brap_Life Posted October 2, 2013 Report Share Posted October 2, 2013 going to be fun if the detonation ruined a lower bearing... Quote Link to comment Share on other sites More sharing options...
yamahaBanshee01 Posted October 2, 2013 Author Report Share Posted October 2, 2013 If you do, it'll end up looking like this. If it were mine, I would do things in this order. 1 Pull the stator cover and see what happens when you try to turn the flywheel back and forth BY HAND. 2 Pull the exhaust and look into the exhaust ports to see what the pistons look like. 3 If you don't see anything bad with the pistons, Consider pulling the clutch cover to see if there's a problem there. 4 If you're going to pull the top end apart, DO A LEAKDOWN TEST FIRST! Is there any chance you ran unmixed gas in it? StarWrite, so heres an update, i pulled off the stator cover, and tried to move the flywheel by hand, it does not turn, my next step is going to be opening the other cover and see if i see anything visible. and than take off my exhaust and look at my pistons. and to answer your question earlier, i did not put straight gas in it. but any suggestions on anything i should do before i take over the other cover? drain the transmission fluid? Quote Link to comment Share on other sites More sharing options...
J-Madd Posted October 2, 2013 Report Share Posted October 2, 2013 You have to drain the water and oil. Quote Link to comment Share on other sites More sharing options...
Starwriter Posted October 2, 2013 Report Share Posted October 2, 2013 The reason I suggested pulling the exhaust and looking at the pistons as #2, is because it's easy and doesn't require a replacement gasket or draining fluids. If you're going to do a leakdown test, you need the exhaust off anyway. Have you looked at the spark plugs yet? If you see the side electrode smashed over or grey specs, that's bad. Quote Link to comment Share on other sites More sharing options...
J-Madd Posted October 3, 2013 Report Share Posted October 3, 2013 The reason I suggested pulling the exhaust and looking at the pistons as #2, is because it's easy and doesn't require a replacement gasket or draining fluids. If you're going to do a leakdown test, you need the exhaust off anyway. Have you looked at the spark plugs yet? If you see the side electrode smashed over or grey specs, that's bad. I was just figuring something came loose on the stator or clutch side since I assume he didn't actually ride it. Good point. Quote Link to comment Share on other sites More sharing options...
yamahaBanshee01 Posted October 5, 2013 Author Report Share Posted October 5, 2013 The reason I suggested pulling the exhaust and looking at the pistons as #2, is because it's easy and doesn't require a replacement gasket or draining fluids. If you're going to do a leakdown test, you need the exhaust off anyway. Have you looked at the spark plugs yet? If you see the side electrode smashed over or grey specs, that's bad. hey starwrite, heres an update.. i took off the exhaust. looked inside and it appears that my pistons are fine. my sparkplugs look fine also. i did uncover a new thing though, i went to the kick starter and tried pushing it down with my hand and nothing. but when i rocked it up and down a few times it started to descend down. im praying thats a good sign?? Quote Link to comment Share on other sites More sharing options...
sheerider11 Posted October 5, 2013 Report Share Posted October 5, 2013 hey starwrite, heres an update.. i took off the exhaust. looked inside and it appears that my pistons are fine. my sparkplugs look fine also. i did uncover a new thing though, i went to the kick starter and tried pushing it down with my hand and nothing. but when i rocked it up and down a few times it started to descend down. im praying thats a good sign??like it wasn't budging until you started slamming it? Quote Link to comment Share on other sites More sharing options...
yamahaBanshee01 Posted October 5, 2013 Author Report Share Posted October 5, 2013 like it wasn't budging until you started slamming it? i wouldnt say i was slamming it, i was just rockin it up and down and it started to come down Quote Link to comment Share on other sites More sharing options...
sheerider11 Posted October 5, 2013 Report Share Posted October 5, 2013 i wouldnt say i was slamming it, i was just rockin it up and down and it started to come downSo no, that's a bad sign. Sounds like it seized and now your breaking it loose Quote Link to comment Share on other sites More sharing options...
Starwriter Posted October 5, 2013 Report Share Posted October 5, 2013 i wouldnt say i was slamming it, i was just rockin it up and down and it started to come down So, now can you turn the flywheel by hand? If so, turn it and take another look at the pistons. there is no way that the pistons seized and don't show some signs of trouble on the exhaust side. Quote Link to comment Share on other sites More sharing options...
yamahaBanshee01 Posted October 5, 2013 Author Report Share Posted October 5, 2013 So, now can you turn the flywheel by hand? If so, turn it and take another look at the pistons. there is no way that the pistons seized and don't show some signs of trouble on the exhaust side. Starwriter, I tried turning the flywheel by hand. it still doesnt budge. but the kickstarter, when i wiggle it very lightly it starts to descend down Quote Link to comment Share on other sites More sharing options...
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