OK so went riding this weekend and quad ran great for 3-4 hours. Than started making a strange noise and died. Got home and pulled the head and this is what I found. Thinking it must have sprung an air leak that leaned it waaay out cuz my jetting is spot on. This is on the exhaust port side. I'm gonna build a leak down tester tomorrow and look for the leak before I do anything. It looks to me like no piston chunks made it into the bottom end.
My question is, should I split the cases to check the bottom end? I'd like to get this fixed ASAP since the weather here in MI is finally nice. Any advice is appreciated☺
Blown top end need advice please
- Thread starter Antonius
- Start date
YES, a million times YES. With that kind of damage there has to be pieces in the bottom end. remove the crank, check the bearings, check rod play and replace as needed. New crank bearings are not that expensive so might just replace them anyways. Remember, if you are having the motor work done locally, make sure you have piston in hand BEFORE boring it. That way you can match bore to piston. OR send the top end out to Ken in CT to do it correctly. Only costs shipping and same price as you can find locally, but for the piece of mind to know its done correctly? If you send it out to him, send your head too for the head mod. Best $60 you can spend on the motor!
Thanks for the reply that's what I figured but I'm new to 2 strokes so most of what I know is from reading on this forum...so you would definitely recommend the head mod too? I've been looking on Ken's site and thinking about emailing him. I'm of course wanting more power but don't want to spend a ton.
The head re chamber will surprise you it adds an inch to the length of your arms.
Before to start the engine, do a leak test to make sure it is airtight.
Before to start the engine, do a leak test to make sure it is airtight.
Think I found the problem leaking between the intake boot and reed cage so badly I couldn't get the case to hold pressure! Can't really afford to get it ported, rebuilt, and piped so think I'll throw a fresh piston in and look for a pipe
Gee,, sounds just like someone else who got a piston of equal size, fit at the top but not at bottom of the bore. Find a shop that can accurately measure bore and tell you what size piston you need for over bore.
Sorry guys should have said I'm taking the jug to a machine shop to measure bore before I order the piston... Than I'll take it back with the piston so they can bore to match. Done lots of reading on this forum, you guys probably have one the most helpful and informative forums I've ever seen! I just don't have the money for a full on performance rebuild unfortunately..
What brand piston are you wanting? Some manufacturers go in .025 mm increments, some go in .050 mm increments?
Wiseco for instance produces pistons in .025 mm (1/4 mm) increments.
Wiseco for instance produces pistons in .025 mm (1/4 mm) increments.
Crank is pretty damn sloppy too haven't pulled it all apart yet but assuming Im gonna have to rebuild the whole thing.. What parts do you guys recommend for the bottom end rebuild?
Parts? None. Phone number? Yes. Who? Ken OConnor Racing.
860-230-5003. Give him a call tomorrow. He will rebuild you crank to near perfection!
http://kenoconnorracing.com/
860-230-5003. Give him a call tomorrow. He will rebuild you crank to near perfection!
http://kenoconnorracing.com/
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