worn intake valves?

[rooster300ex]

I noticed when I got my quads motor back that the recipt showed that he installed 2 intake valves. Could that caused my motor to smoke on start up and when it got hot on decel? He said it was the rings though. What are usually the reasons you replace valves?

I can't wait to get my motor in and everything put back together. Its been 3 months since I rode. I bet some know the feeling.

[GPracer2500]

Worn intake valves are not uncommon. Filtration has a lot to do with it. I'd ditch the K&N and start running a foam filter. Keeping your intake air filtered as much as possible is one of the best things you can to for your intake valves.

[rooster300ex]

Originally posted by GPracer2500
Worn intake valves are not uncommon. Filtration has a lot to do with it. I'd ditch the K&N and start running a foam filter. Keeping your intake air filtered as much as possible is one of the best things you can to for your intake valves.

Well them intake valves have been in there since 1995 and just now had to be replaced. I'v been hearing all kinds of things about k&n's. Everytime I take my filter off to clean it I take the airboot off also and its clean as a whistle.

If I did change to a uni type filter will I have to rejet. I know have the 128DJ 3 turns out on the fuel screw and on notch 4. I also run no lid with a outerwears on the filter and an outerwears airbox cover.

[GPracer2500]

Originally posted by rooster300ex
Well them intake valves have been in there since 1995 and just now had to be replaced. I'v been hearing all kinds of things about k&n's. Everytime I take my filter off to clean it I take the airboot off also and its clean as a whistle.

If I did change to a uni type filter will I have to rejet. I know have the 128DJ 3 turns out on the fuel screw and on notch 4. I also run no lid with a outerwears on the filter and an outerwears airbox cover.

10+ years is certainly an exceptable valve lifespan as far as I'm concerned (for a performance quad). If you're happy with your K&N then no reason to change it. I run a K&N on one of my machines myself. Nonetheless, they do not filter as well in dusty conditions. Particulates that find there way to the intake valves reduce their lifespan (same for the bore). That's why I mentioned it.

Racing motorcycles that use no airfilter at all can have very short intake valve life. Having no filter at all is obviously an extreme case--but I've seen what it can do to intake valves. Running a K&N (or not taking care of your filter, no matter what type it is) does the same thing just at a much slower pace.

If you changed to a UNI I'd probably go one size leaner on your main and call it good.

[rooster300ex]

Originally posted by GPracer2500
10+ years is certainly an exceptable valve lifespan as far as I'm concerned (for a performance quad). If you're happy with your K&N then no reason to change it. I run a K&N on one of my machines myself. Nonetheless, they do not filter as well in dusty conditions. Particulates that find there way to the intake valves reduce their lifespan (same for the bore). That's why I mentioned it.

Racing motorcycles that use no airfilter at all can have very short intake valve life. Having no filter at all is obviously an extreme case--but I've seen what it can do to intake valves. Running a K&N (or not taking care of your filter, no matter what type it is) does the same thing just at a much slower pace.

If you changed to a UNI I'd probably go one size leaner on your main and call it good.

Hey man thanks for the knowledge. So I could just put in the 124DJ and call it good with a uni? I do take good care of my k&n. I clean it after just a few rides. Do you think running a k&n made my rings only last a couple of years. The stock piston and stock filter lasted since 1997 with no problems. I wanted to ask the shop why in the hell are my rings shot after a year or two.

[GPracer2500]

Poor filtration can certainly impact ring life and bore life.

I'm just guessing on the jetting. Typically a foam filter won't breath quite as well as a gauze filter (K&N) so dropping down one size isn't a bad bet. Kind of depends of the foam filter. I've had some that seemed really thick and dense and others that seemed to breath pretty darn well (like most UNIs). With a UNI you'd probably be alright not changing anything--it just depends on how precise you are with your jetting.

If you change filters, put in one size smaller and test it out. See what you think.

[rooster300ex]

Check your PM's GPRacer