Maintenance Day- Cam Chains-Valves

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Maintenance Day- Cam Chains-Valves

cbRider
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Hi, today is maintenance day on the 81 CB750F.
Today I would like to check the valve clearances and the cam chain tension.

My first problem is the tension on the intake cam. The chain is as tight as a drum and I can't seem to find a way to slacken it. It is much tighter then I like it.  Not being familiar with the tensioner mechanism I wonder if someone could steer me toward an exploded view of the thing.
Also the way the Clymer people say to adjust the chain is a joke. Try to loosen the two nuts under the carbs while the engine is running. I wonder what they're smoking.

I would be quite thankful if someone here could help me with this problem?

Thanks,
Karl

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Re: Maintenance Day- Cam Chains-Valves

OTTODOCTOR
The method used in the manuals is fine , and it can be done , although it is a pain in the ass . The adjusters on the rear of the cylinders are actually the exhaust cam chain tensioner . -- Easy way is , ( engine cold ) pull timing cover from left side of engine -- ( 3 screws ) -- Loosen tensioner nuts on rear of cylinders and rotate large nut on top of ignition trigger slightly counterclockwise to let auto-adjusters take up the slack. Tighten nuts on rear of cylinders ---- Use same method on intake cam chain adjuster ( bolt/nut on front of cylinder bank ) Loosen lock nut and bolt . After tension adjusts automatically tighten the bolt first , then secure the nut down to lock the adjustment . -- Note -- They will seem TIGHT , but the auto-adjusters place the right amount of tension on the chains .
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Re: Maintenance Day- Cam Chains-Valves

cbRider
Hello Otto, thanks for the reply.
To me it seems the intake cam chain is too tight and I can find no way to release all that tension.
In all my years of repairing and tuning sports cars, racing cars etc I have never seen a chain as tight. I can't even budge it with leverage.

Karl
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Re: Maintenance Day- Cam Chains-Valves

OTTODOCTOR
Springs are pretty strong and the tensioners lock in place when you tighten them . Not much give to them .