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My426Hauls

Valve adjustment symptoms??

8 posts in this topic

Hey, i have a 2002 yz 426 and i was just wondering how i would know when to check the valve clearances. Right now when i ride it at idle i can kinda hear the valves clicking and at high rpms it will pop every once and a while so i was just wondering if it is time to check the valves

Thanks

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Can't hurt to check them for piece of mind. I usually check mine once a season.

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Hey, i have a 2002 yz 426 and i was just wondering how i would know when to check the valve clearances. Right now when i ride it at idle i can kinda hear the valves clicking and at high rpms it will pop every once and a while so i was just wondering if it is time to check the valves

Thanks

Keep in mind that generally the valve clearance will tighten over time so it's probably not going to be making noise ..... and I concur w/02YZ426 , check em' ! It's easy .

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If you have any question, check em. I usually check mine a couple times a year.

One of the big symptoms of out of spec valves is the bike will get more difficult to start, especially when cold. You may also notice some loss of compression.

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Another one is a "hanging" idle that suddenly develops for no other apparent reason that can't be entirely corrected even after you have run the fuel screw way out of range. (tight intakes)

As stated above, the norm is that clearance will decrease, because almost the only thing that actually wears to any significant degree are the valve faces. That makes them move up into the head.

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I've had to have mine adjusted twice in the last 100hrs riding time on my '02426. I believe however that an inferior air filter was the culpret for excessive valve wear and have remedeed the problem now, I hope. The manuel suggests checking them every 30hrs I believe. My symtoms were mid-range popping and low compression when cold.

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Dirt past the filter will definitely eat the valve seats in a real hurry. Keep an eye on them; sometimes once they start to get eaten they wear very quickly from that point.

In regards to the original question; check the valves, it's easy. As said above they will tighten (not loosen) with time. This is because as the valve and seat wear, the valve moves closer to the cam when it's closed. If they get too tight and start to leak then you run the risk of burning the valve and the seat and that's a hassle and expense that you don't want to deal with.

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