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Cam Free Play

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I have what may be a stupid question but here goes. I was told by a bike mechanic that my valves can not be adjusted anymore and I need a new head and valves. After 4 weeks of sitting in his shop and nothing being done I picked it up and decided I would remove it myself and get it replaced/repaired. I pulled the head off and decided to check the thickness of the shims myself. I pulled the intake buckets off and saw they were stamped 1.20 (intake) 2.75 (Exhaust). So I put the cam in and torqued it to 16nm and the cam has free play (See video). My question, is this normal? I was under the impression that when the valves needed adjusting that there was too little gap and it held open the valves. Some please educate me if I am wrong. Thanks.

 

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you need to check clearance with feeler gauge! yes you should beable to rock the cam alittle with int. and exhaust closed

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3 minutes ago, mv7000 said:

you need to check clearance with feeler gauge! yes you should beable to rock the cam alittle with int. and exhaust closed

I know about using a feeler gauge to check clearance but I did not think there would be that much free play like this when at TDC. The way it was explained to me that there was no clearance and that the valves were being held open because of it. Then I find free play and it doesn't make sense, I feel like he was blowing smoke. I would think that maybe the valves seats are bad or the valves are cupped. Not because he could not find a shim small enough. 

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So it sounds like you know what sizes all the shims are, right?  But it doesnt sound like you know what the valve clearances are with those shims. Check the valve clearances.

The 1.20 shims are the smallest shims in the kit, so if the valve clearances are too small you need to do something about that.

The free play or cam movement your asking about isnt the issue and there is no reason to be concerned about that.

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1 hour ago, TDW said:

So it sounds like you know what sizes all the shims are, right?  But it doesnt sound like you know what the valve clearances are with those shims. Check the valve clearances.

The 1.20 shims are the smallest shims in the kit, so if the valve clearances are too small you need to do something about that.

The free play or cam movement your asking about isnt the issue and there is no reason to be concerned about that.

Thanks. I was a auto mechanic 30 years ago for GM and cars never had any free play so I not expecting it. I checked the exhaust and they are in spec. The intake are not. I tried all the way down to .008 and still couldn't get it in.

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1 hour ago, tjne said:

Thanks. I was a auto mechanic 30 years ago for GM and cars never had any free play so I not expecting it. I checked the exhaust and they are in spec. The intake are not. I tried all the way down to .008 and still couldn't get it in.

 

1 hour ago, tjne said:

Thanks. I was a auto mechanic 30 years ago for GM and cars never had any free play so I not expecting it. I checked the exhaust and they are in spec. The intake are not. I tried all the way down to .008 and still couldn't get it in.

intake spec are .005 +/- .001

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I was looking at the "mm" thinking it was "in". I will do it again.

 

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Here is a good link with pics that might come handy when you want to check or adjust valves with the head on the bike.

 

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4 hours ago, Masterpeen said:

After the 3rd re shim it's usually time for new valves

Is it mostly the intake valves that go out of adjustment and why? I would think the exhaust would because of the heat.

 

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Intakes because of bad air filter maintenance. I'm referring to stock titanium valves. Once the coating is gone the will wear extremely quick. When replacing your valves you will need to have the valve seats done in the head or you will get less then 50% of the normal life span. You cannot lap modern 4 stroke valves

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1 hour ago, tjne said:

Is it mostly the intake valves that go out of adjustment and why? I would think the exhaust would because of the heat.

 

The lightweight titanium intake valves were originally installed for performance not longevity, because the bike is designed for competition and has a high revving high output engine suitable for racing.

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