Author Topic: valve adjustment questions  (Read 1155 times)

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Offline cb650 bobber

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valve adjustment questions
« on: July 08, 2009, 07:20:36 AM »
I was wondering if there were any ways to notice if need a valve adjustment. Also if you dont do one will it hurt the engine.
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Offline mattcb350f

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Re: valve adjustment questions
« Reply #1 on: July 08, 2009, 08:11:16 AM »
I was wondering if there were any ways to notice if need a valve adjustment. Also if you dont do one will it hurt the engine.

There is no absolute way of telling if you need a valve adjustmet externally, however the noise of the valvetrain can be a clue. If there is a lot of rattling comming from the top end they may be loose while if there is no rattling at all, then they may be too tight.

The valves need adjusted periodically, so if you know when they were last adjusted, then checking the recommended period in the manual will give you a time to do them. Otherwise, If you've never done them.....then you probably should.

Not adjusting them can lead to expensive problems. If they're too tight, it can not only damage the cam, rockers, and chain but burn the valve seats/valves which can only be repaired by rebuilding them.

Too loose and you can mushroom the end of the valve stems (bad).

Also, only the proper setting will give you the best performance. Too loose or too tight will cause a power loss.

 Matt.
1974 CB350F,  1980 CB125S,  1981 XL80S
Non Honda's: 86 & 87 Husqvarna 400wr's

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Offline Cvillechopper

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Re: valve adjustment questions
« Reply #2 on: July 08, 2009, 09:05:30 AM »
^^  What he said ;D

If you've never done them (on this or any other bike) make sure the go through the ENTIRE tune-up procedure in order.  Read the manual carefully and spend a couple hours getting familiar with your bike.  It's good for the bike and the soul.
These are the items (other than basic fluid changes, etc) that you need to do on a fairly regular basis.

Order:
Adjust cam chain tensioner
Check/Adjust valve clearances
Check/Adjust ignition timing (points gap then timing)

Optional/ As needed
Adjust idle screws on carbs
Synchronize carbs
It is the mark of an educated mind to be able to entertain a thought without accepting it.  Aristotle