newbie questions

Hi everybody, great site you have here.
I just bought a 1982 xj750j and was wondering if it is normal for all of the valves to be too tight? also the cam chain appears to be rubbing on the cam cover so is it time for replacement?The bike has approx 38880miles/63640klms and other wise seems to run pretty darn good, any thoughts would be great.
Thank you

 

It is normal for all the valves to have "settled in" and to be tight. The repair manuals make it sound like they're all going to be too loose. I don't know too much about the cam chain, I've never had an issue with mine, but a lot of people have, and often it can lead to the unpleasant, 'my chain guide exploded' problem.

 

The Cam Chain ought to be good for close to 50,000 Miles. That's LESS than the figure in the Factory Book, in order to err on the side of Safety.

The Cam Chain Tensioner probably needs to be adjusted. Your bike is within the window of possibly having a Tensioner that is NOT Automatic.

In that case, you have to adjust the Slack out Manually.

If its Automatic ... it can be adjusted quite easily.

Remove the left side crankshaft cover.
Loosen the Tensioner Lock Bolt.
Pull the spark plugs to allow the engine to be turned-over easily by hand.
Take it Two Full Turns -- Clockwise and Stop.
Quickly turn the engine over COUNTER-Clockwise ... allowing the slack to be pulled-down across the front and brought-up the back side in front of the tensioner.
The Tensioner should react to the slack being brought around to the rear side right in front if it ... and automatically extend itself out to compensate for the change in tension upon it. It usually "Clicks" as the one-way cam allows the movement.
Re-tighten the Lock Bolt.

The valves are normally close tolerance. 0.004 (Four thousandths) being the limit on most bikes. If they are tighter than Four-thou ... you need to re-shim.

 

Thax for the quick replies, when you say tensioner lock bolt do you mean the bolt on the end of the tensioner as mine is the automatic flavor kind.
Thanx again.

 

Yes. If you aren't in a hurry ... I'm writing it up as a Pre-season adjustment.

Later tonight.

 

What do you mean by tight? Tight as measured by a feeler gauge against the shim?

 

At room temperature your intake clearance should be 0.11~0.15mm and exhaust clearance should be 0.16 ~ 0.20 mm.

 

Yes the claerances are to tight as in measured by a feeler gauge.do you think it will hurt it to ride it this way as I cant afford the two hundred bucks for the shims right now if it is going to hurt it then I guess I will have to wait,BUMMER
It is suppose to be a nice warm weekend so of coarse the bike will be down.

 

What ... exactly, did they measure-out at?

If the answer is that there's NO clearance and the cam is riding the shim ... park it ... right now you only need shims.

Ride it ... and you might be needing valves.

 

Unlikely for all to be too tight, how exactly are u checking the shims & what value does the feeler gauge come up with? u need to have all valves closed before checking any clearances.

 

Danno:

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Year - Model - Total Miles - Stock or Mods - Condition

Please start a new thread. There's too many "Newbee Questions" to keep straight.

Tight Valves. Need Shims and Advice.

 

Shims are $3.95 each. Worst case you need 8, $32. I think shipping is about $3. Valve shim tool is about $20, or you can search the forums to see some methods to do it without a tool.

In my gallery there are photos showing the valve shim measurement.