Valve shims and cam chain.

Ok, I'm just going through the scheduled maintenance list and knocking things out one by one.

I have the 1982 XJ750 Seca

I just changed my final drive oil and now I want to check the clearance on my valve shims. I remember a couple weeks ago I saw a great thread on that. Anybody have a link? Also, does anybody know exactly what the acceptable range of clearance is? Also, at what point does it become a hazard?

The other thing I wanted to do is reset the tension on my cam chain. I saw a thread on that too. I wanted to give that a try since I'm going to have my headcap off anyway.

Thanks!

 

bigfitz prepared a great "documentary" on checking and correcting the valve clearances here:

http://www.xjbikes.com/Forums/viewtopic ... rance.html

There is also a table which shows what the clearance values should be and how to achieve the correct clearance if they are out of spec. The implications of tight valve clearance is burned valves and other such horrors as well as difficulty in getting a good synch. It is therefore the first step in achieving a well tuned engine and one of the first items on a to-do list.

 

One thing really quick.

Should I drain the oil before removing the crank case cover?

 

The crankcase cover as in the clutch cover? Not necessary if you place the bike on the side stand. If you mean the cover to turn the engine over by hand then no to that also.

For your camchain adjustment, I have the manual tensioner so my procedure is different to those bikes with auto tensioners (if yours has an auto tensioner) but do a search, I believe Rick posted a guide on how to "help" the auto tensioner.

 

helping the auto tensioner is easy.

take the left sidecover off.

remove all 4 plugs.

put a 19mm wrench on the crankshaft nut.

turn the motor backwards (clockwise) two full turns slowly and stop nice and smooth.

this will place the chain slack in front of the tensioner.

have a friend tap the tensioner bolt with a hammer handle as you quickly turn the motor forward (counter clockwise) about a half turn.

do it a couple times.

don't loosen anything on the tensioner.

 

Alright guys, thanks a bunch.

I just bought the tapet gauge and checked my valve clearance. The clearances were PERFECT!

I still have a "tick" in my valves, is this something I should still worry about, or should I just forget about it?

I also tried that fix with the cam chain. I thought I got it, it made a "chunk" sound, but i'm still getting a "whizzing" noise and I think that's my cam chain. Anything else I should check out?

 

Sounds like you have the same sounds as me...
Either we are both paranoid, or we both have the same issues.

I have to get my bypass holes in my carbs cleaned out... then we'll see where I am at with sounds.

 

Yeah, keep me updated with that.

How does your bike run? Mine seems to run fine, but it idles rough until it has been going for about 30 min.

 

the whizzing noise may be the middle drive gear sound, nothing to worry about. It probably takes a long time to warm up, I know mine does. I have to ride about 10 miles or so before i can stop and idle without help from the choke.

 

From what I understand Rick to have said, some valve noise is GOOD on these bikes....no noise is BAD.