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Interesting valve check...

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I had my CRF for sell and some young kid came to look at it. He started it up, let it run for a second, and then covered the muffler with his hand while he listened to the engine. :worthy: took his hand off and said "it needs a valve adjustment" :):D

Am I way out of the loop and this is the newest greastest way to check your valves?? Never seen this done or heard of it before.

I've been pretty involved with CRF's since 03 and this just has me stumped...

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You cannot tell like that, :)

If you hear too much valve train noise - like tapping, then the clearances are too loose, and easy fix.

Or if it gets hard to start all of the time, that would mean they are too tight and need adjustment, then soon after a proper valve rebuild.

The only way to know for sure is pull the valve cover and check them. You could prolly do it in 15 minutes.

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I am assuming that he could tell that it needed a valve adjustment by listening to the motor. He put his hand over the exhaust to just quiet the background noise so he could hear the motor better. That is the only thing I can think of. I have been known to be wrong at times though :)

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I had my CRF for sell and some young kid came to look at it. He started it up, let it run for a second, and then covered the muffler with his hand while he listened to the engine. :worthy: took his hand off and said "it needs a valve adjustment" :):D

:ride:🤣:banghead:🤣:banghead:🤣:banghead:🤣:banghead:🤣:banghead:

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If the exhaust valves aren't closing all the way(to tight) wouldn't it create a vacuum and draw air into the pipe when the piston was going down? I've seen people check this by holding a piece of paper by the tail pipe when the engine is at idle. In theory it would...

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If the exhaust valves aren't closing all the way(to tight) wouldn't it create a vacuum and draw air into the pipe when the piston was going down? I've seen people check this by holding a piece of paper by the tail pipe when the engine is at idle. In theory it would...

If it were bad enough to be visible I doubt the bike would be running, if it is sucking on the intake stroke it will be blowing on the compression stroke and losing all the compression.

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I really had to chuckle when he did this, I'm still not sure what he was listening for. 👍:worthy:

He was serious about buying it so I said I would adjust the valves. The exhaust side was a little loose, like .001 out of spec. Didnt sound any different after I re-shimmed it, he did the same procedure and said "sounds good"... :blah: It just makes laugh now, he bought the bike so its all good. Although I dont think I will ever forget the "interesting valve check". Heck maybe I'll try an convince some of my buddies to do it...:busted:

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what makes me laugh, and correct me if I am wrong, is that most people feel the world will tumble down if the valves are too loose.

It the other scenario that should have you worried....valves getting too tight.

Anyways, tell the next guy who says that to explain why noisy...aka loose...valves are a bad thing over quiet....aka too tight....valves.

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what makes me laugh, and correct me if I am wrong, is that most people feel the world will tumble down if the valves are too loose.

It the other scenario that should have you worried....valves getting too tight.

Anyways, tell the next guy who says that to explain why noisy...aka loose...valves are a bad thing over quiet....aka too tight....valves.

Valves too loose will cause premature wear of valves, seats and maybe even the cam due to increased lash. But providing it is adjusted quickly enough it will be OK.

Reduced clearance on the Ti valves (tight) means the coating is gone and the valves are shagged.

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I really had to chuckle when he did this, I'm still not sure what he was listening for. 👍:worthy:

He was serious about buying it so I said I would adjust the valves. The exhaust side was a little loose, like .001 out of spec. Didnt sound any different after I re-shimmed it, he did the same procedure and said "sounds good"... :D It just makes laugh now, he bought the bike so its all good. Although I dont think I will ever forget the "interesting valve check". Heck maybe I'll try an convince some of my buddies to do it...:busted:

Thats funny, you should post your story in that the thread over in the lounge. Something about "strange dealings you have had with buyers". That one is pretty strange I must say, I would have thought the kid was a tire kicker but it sound like he genuinely believed that the valves were out. You should have just left the valves the way they were and told him they have been adjusted. Im sure he would have said the same thing, sounds good now, thanks for adjusting the valves! lol. What a goon.:blah:

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By reducing the external sound of the exhaust it can make it much easier to locate internal noises. Could you tell the valves were out .001", no, but you could also hear many other potential problems. I will give the kid credit, at least he took the time to look over the bike, do his "tests" instead of just handing over the money. Plus he also got to rest assured that the valves were in spec.

Kell

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Did he drink some of your oil to see what condition the bearings were in:cheers: 👍

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