valve spring issues

[wolffie]

i have been having some problems with my clearances tightening up. after the second time of having the machine not start without being "pop started", i reshimmed everything again, and went from like a 165 to 150 shim on my intake sides, and the clearances barely even moved (i couldnt even slide a .002" feeler gauge in, and that is thinner than paper)!! the exhaust sides were fine though.

i was told that my springs were worn out (which i would imagine is true) but does that mean that i need a new piston because my compression has suffered? the machine runs fine once it is pop started but it wont start worth a chit otherwise!

the problem is, i NEVER had the initial 20hour valve checkup when i bought the machine because there are no dealers around where i live. i ended up having to learn how to do it myself after around 5months. i take very good care of the machine, but due to no dealers around me, i have to do ALL my own work. i think the experiences i am getting are great, but i dont always have the money to cover up these little "learning mishaps", lol!

[underpowered]

your valve springs have nothing to do with your valve tighening up. the reason only your intakes are moving and your exhaust are not is the material they are made of. intake valves are made of mild steel, while the exhaust are hardened since they have to deal with much more heat. Your intake valves have simply "pulled", they are being rounded off on the end and sucked up into the head. it is a common problem found on many newer four strokes. A good fix is to replace the valves with Kibble white Black diamond stainless steel valves. they will last much longer than the stock ones and are about the same price. BTW i did not catch what type of quad this is on?

but a solution for this is to change how you ride. do you ride near teh rev limiter? do you hit the rev limiter often? it is amazing ho just by riding a 1000rpm or so lower in the rev range will prolong the life of internal engine parts. It may be as simple as jsut changin how you ride, or you could change things on the bike like gearing or i actually changed cams on my bike to change teh powerband to keep me away from the rev limiter.

[GPracer2500]

Valves that keep going tight usually mean the valves and valve seats have worn beyond the point of no return. Some valve materials/designs are more prone to this than others--but once they've worn to a certain point they start wearing away fast and won't stay in spec.

It can be dangerous to run an engine with tight valve clearences. If the valves get to zero clearance there is a very real danger of breaking off the end of the valve into the cumbustion chamber. That kind of failure gets expensive in a hurry.

Intakes valves are more likely to wear (and go tight) then exhaust valves. The primary reason for this is tiny pieces of dirt making it through the air filter and inbeding themselves in the valves and seats creating an abrasive surface. You might want to think about ditching the K&N and using a foam filter. Foam filters are generally superior at preventing the ingestion of those fine particles.

It sounds like you need (at least) new intake valves. While your in there you can measure your valve springs and piston (or have a machine shop do it) to determine if they are still in ok condition. Even if the piston turns out to be ok a new set of rings would make sense. Whatever the case, once you tear it down you can start figuring out which parts need to be replaced.

[wolffie]

thanks alot for you input guys!

for some time i tried experimenting with a Honda Civic air intake and i believe that probably wasnt the best thing for the quad.:ermm: at any rate, i will be calling up a local machine shop! thanks again:)