When are reeds worn out?

[rablack21]

I have a rad valve with the pro series carbon fiber reeds. How can you tell when they are worn out when it is on a running motor? I'm not talking about a visual inspection for cracked or bent reeds. What are the characteristics of reeds that need to be replaced? I haven't replaced these in a while and I wondered what the engine would act like when they got old and worn out.

Inconsistent and erratic behavior, hard starting, and worn out reeds will act like the jetting is to rich…

Carlos.

[rablack21]

The behavior has been weird lately. It's not hard to start. I had the engine rebuilt recently. It is good and broken it now, and the jetting is good. It doesn't have the same power it did before I had it rebuilt. It used to pull the wheels off the ground in the first 4 gears or so, but now it doesn't pull near as hard. It acts like it has a very narrow power band, but it doesn't pull very hard and it stops pulling very quickly. It's like the engine rpm's rev up quickly but it just doesn't pull as hard as it used to or for as long. I know it is not the rebuild. But I can't figure out what the deal is. I haven't changed the reeds in quite a while so I was wondering if this was the cause. And any jet changes I seem to make don't really change anything much.

[atvmxr]

i still have the original reeds that came with my FMF ram valve, not quite 20 years, but well over 15. I've found reeds to be pretty durable...

[rablack21]

That's pretty durable. Mine aren't quite that old. That are about 8 years old or so. They have really only been used much for about 2 years or so. If the reeds aren't the problem then I am puzzled.

[fearlessfred]

if the reeds are sitting flat on their seats and covering their windows they are fine and would look elsewere for the problem. dont be so sure of the rebuild do a compression ck. to be sure. this may sound insulting ,but is not ment to be. a broken ring when assembled , rings that were not gapped enough,( to little gap on the rings will cause them to break in out of round and will never seat properly ) i hope im wrong and its something simple maybe the clutch

[addictedtomud]

Your clutch springs may need replaced.

Same thing happened to me recently and I just figured the engine was getting tired and ready for a rebuild. Quad just didn't pull like it used to. But then the clutch started noticeably slipping during a ride. Got worse and worse and I almost didn't make it home! When checking the clutch, the plate thickness was in spec, but the spring length was way short. I replaced the springs and it's like a brand new motor again!! Pulls hard and crisp just like it used to...

Only thing I can figure is that after so many years of these springs sitting there under tension (even while the quad is parked) the metal must have finally fatigued enough to permanently compress

Cost me $8.00 to fix it !!

[rablack21]

AddictedtoMud and fearlessfred,

I think you guys are on to something. I don't think that my clutch springs are worn out because they are still pretty new. But I did have a problem once before when I had my clutch cable adjusted too tight. When I got my motor back from the rebuild, I just put it in and adjusted the cable back to where it was before. However, it could have changed the pull some and now it may not be fully disengaging the clutch. I'm gonna check the clutch cable adjustment right away and let ya know if that was it.

[rablack21]

I adjusted out the clutch. That didn't do anything unfortunately. I'm going to do a compression check and go from there.

[fearlessfred]

let us know what it is

[rablack21]

I believe I found my problem. I checked the compression this morning. It was 150 psi. Before the motor was rebuilt, I was using a 3 wheeler head gasket which put the compression at 185psi. I put a regular head gasket back on it,(one of those with 3 thin gaskets pot riveted together). Now the compression is 150psi max. I bet that is the performance difference I am feeling.