shimming valves...

i'm really not thinking that i ruined my shims by grinding them... aside from the possibility that i could mess up and put a taper in the shim (I didn't they're perfectly flat) what is the harm in doing it?

 

The harm is that the Underside is perfectly flat and fits the Bucket in such a way that the Oil bath it's in provides hydraulic tension keeping the Shim from vibrating and lessening the chance that you will ever "Throw a Shim".

Grinding the shim take away its perfect "Flatness" ... the shim is more likely to vibrate and allow some Engine Oil to find its way into an imperfect area ... causing the possibility of two major problems:

1. The Shim will begin to act like a Hydraulic Lifter and at High Revolutions try to escape from its machined mating surface atop the Bucket.

2. The imperfection ... however slight ... will cause the Cam Lobe to become worn-out because the entire surface of the Lobe won't be in contact with the shim.

1. If you throw the Shim and it gets caught between the Bucket and the Lobe ... the Cam Shaft will bind and a Catastrophic Failure will be immediate as the Cam will fracture.

2. You'll need to have a new Cam or get the one you have refaced.
Buying a new Shim is going to be a heck of a lot cheaper than buying a new Cam or sending your out for a Lobe repair.

 

hmmmm point taken.... looks like i'm off to the dealership...

 

I'd suggest a local salvage yard first -- that's what I did for mine. Paid $5 apiece. Failing that, hit up Chacal.

 

Does the gasket need to be replaced every time you check (or do anything) with the valves?

I'm about to open her up, never done it before...I'm scared, mom...

 

Not if the gasket was put-on right.

If whoever put it on last time lubed the face of the gasket and the Heads mating surface ... the Gasket should stay right in place on the Cam Cover.

If it doesn't ... IF it's NOT ripped ... you can use it again IF you take precautions to make sure you get a good seal.

++++++++++

And now ...,
for another exciting edition ..,
of - -

The Old School Method
by: Rick Massey
All rights reserved.

Fitting the Cam Cover Gasket.

Clean the gasket-lip channel out real good. Use a toothbrush and some Carb Cleaner and get it ... well, clean!

Rinse-out the channel with a little Isopropyl Alcohol if you have some. Any kind of cleaner with alcohol. I've used Windex once or twice. Nobody was lookin'! When I get ready to do this on my suh-whee-eat Max ... I might just use some Johnny Daniel's. His good friends don't need to call him Jack. Johnny's OK for some of his best friends.

OK ... we got it clean.
You need one tool. The best tool for this gasket job comes scotch taped to the can of carb cleaner. The little red tube that switches to guided missile; then hides!

Elmer's Glue-All.
Elmer couldn't quite figure-out what to put on the label so everybody would know it's really Elmer's Glue and not a Knock-off ... so, he puts a nice likeness of his grandmother on the front, too.

OK ... so, we got the Elmer's Glue in one hand ... and, the little red disappearing tube in the other. Normally, I should not have to explain this process any further. I'm sure there's a light bulb over the heads of a good many of you already.

Yes ... the trick is to lay a film of the Elmer's Glue all around the channel Seat the gasket in the channel. Don't sweat the mess. Use any of the ooze-out on a place that might have had the glue spread too lean. Pat it all down, all the way around ... and, use this opportunity to make the gasket fit perfectly by shifting it ... if it needs it.

When the glue on your fingers starts to get tacky; finish-up the installation by seating the gasket, once again.

Clean-off your fingers and the top surface of the gasket with a damp cloth making the flat, contact surface of the gasket ... clean.
When the top surface is clean ... Paint it with clean oil. I just use a Q-Tip dipped in Marvel Mystery Oil. Any clean oil will work.

With the Gasket oiled "Set the Gasket" all around, by running your fingers over the whole Gasket; applying a little pressure to seat the locating tab firmly.

Clean the mating surface all around the top of the Cylinder Head. The glue will be ready right after you get the cylinder head cleaned-up.

Here's the good part:

Now, paint the Cylinder Head mating surfaces with a light sheen of oil.
Paint the gasket with another light coat, too!

The gasket will not become displaced when you put the cover back on and position it.
The oil is going to allow the gasket to flatten-out when you tighten it down.
This treatment is going to allow the Cam Cover to be removed again ... without the "Gasket Hassle."

The clean-up is going to be quick and easy ... Elmer's Glue-All is water soluble.
Using Elmer's is perfectly safe.
(Little kid's have eaten the stuff)

Piece 'O Cake!

And, ... Now that you know "The Old School Method" you'll NEVER have to hassle with the gasket again.
You seated it perfectly!
It won't leak.
I promise.

- 30 -

 

Hey Oak.....if you use some type of non-stick coating on the bottom of the valve cover gasket---the side that contacts the cylinder HEAD----and use some really good glue on the top of the valve cover gasket----thes side that contacts the VALVECOVER-----then if you're lucky, and hold your neck just right, and the major planets are lined up properly.....THEN you can remove your valve cover and have the gasket come off with the valve cover and life is good....

But in any case, the answer to your ?? is NO, you don't have to replace the valve cover gasket everytime you remove the cover. However, over time the gasket shrinks a bit, and once you get more than 2-3% shrinkage on this gasket, if it comes loose from the valve cover, it's basically impossible to get it back on due to the complexity of it's shape and design.

You'll see!

 

If you do it right ... and lubricate BOTH surfaces ... the Gasket comes right off and adheres to the Cam Cover for replacement without any difficulty.

You have to paint some Oil on the tow mating surfaces each time for this to be successful.

 

Out of curiosity, I was told by my local Yamaha dealer that using engine flushes would be fine on my xj. I did so, and it seemed to clean up response on the clutch. Do you think SeaFoam would be a good/bad idea? I can't see it hurting anything.

 

Jerry, Seafoam is basically a light petroleum derivative product, along the lines of kerosene, and basically IS an engine-flush! Just don't over-do it, and never "ride it" with such solvents in the engine.....just run the engine at idle, and gently up and down the rpm range, while the bike is parked!

And then it's not a bad idea at all to drain the oil/flush mixture, fill the engine up with cheap oil, run it again (not under load) for a while, and then drain the cheap oil and replace with good oil. You want to make really sure that the flush gets as fully OUT of the engine as possible!

 

Aha, right. I recall the kerosene being the main chemical being used in most engine flushes. Well that's good to know, thanks chacal I now have a few loud valves, and a slipping clutch to resolve. Nothing that won't last another riding year or two.

 

You're very welcome! But.......

Not a good thing. Might want to check the shim clearances, and remedy as needed. A lot cheaper than having to do major head work at a later date!

 

Good point. I find the valves are significantly loud only at certain low rev points. I don't hear them TOO much besides then. Again good point though. I'd hate to have to pull the head all apart in the middle of riding season. :O

 

I have always said that there are GOOD Noises that Engines make.

Noisy Valves CAN be good Noises. But, the noise can't be too severe.
A Noisy Valve within specs is OK because you KNOW that Valve is closing.

It's when your Valve Train ISN'T making noise that you need to get nervous and check the clearances of all the Valves.

If they are Noisy ... but, within specs ... leave them be.
If they are Noisy ... AND, out of specs ... adjust the Clearance by changing the Shim.

You shoeld hear all kinds of Noises if you are Flushing-out an Engine with a light weight petro-product in place of recommended lube.

Valves, Clutches and Idler Gears should be making a racket until you get them quieted-down with the right weight Oil.

Don't be running that Engine at any great speed without the right weight Oil in there ... or, you'll have noises that you don't want to hear.
Bearing knocks!

Without the right weight lube in the Engine the risk of spinning a bearing is pretty high ... so, flush-it ... drain-it and get it filled-up with the right stuff before anything you'll regret happens and puts the Bike out-of-commission!