shimming valves...

.... sucks really bad. i hope i never have to do it again.

 

I'm about to tear into mine soon. I'm waiting on the new cover gasket and bolt rubbers then I'll start taking things apart. It doesn't look too complicated to me. I have a Clymer manual with all the photos and directions, so I ain't sceered.

 

It would be no big deal if you had an inventory of shims handy. Problem is you end up doing it twice - once to figure out what you need and a second time after the shim order comes.

 

I guess I didn't think pulling the discs out was a big deal. I guess I figured making the tool was harder than using it? I'll find out I guess.

 

I've read the procedure. Why can't I make up 8 wooden shims so I can pull the steel ones out? I have a spare motor to swap shims from. The wood won't hurt the cam. Having all the shims out at the same time would help?

 

Hey, that gives me an idea!! I have a 650 Maxim motor just sitting here too! I may have to tear into that one and see what size the pucks are! Thanks for the idea TimetoRide!

 

I bit the bullet and had the dealer adjust mine. They put in two shims and charged me $102.30. They said they adjusted the cam chain too. They must have adjusted it looser because it rattled worse than I've ever heard it. I took 5 minutes and adjusted it myself and it is perfect now.

 

I did mine a few weeks ago, its a tedious job, but not a hard job. It helps if you make a plan so you know which valves require new shims and which you can switch from other valves, them map out the moves so you always have the proper shim out when your going to need it.

 

It might be a royal pain to the regular person (something I'm far from it seems) but if I need to pull all the shims, I have simply removed the cams. Bit more work and not without its risks but a real quick job of swapping out shims if you've done your homework.

 

Exactly what I ended up doing as I had to replace all but 2, so it was easier to pull the cams and relocate/replace the shims and put it back together. I was fortunate that the Yamaha dealer close by just let me swap them out for what I needed as they said they have no call to use what they had in inventory... Now they shut the place down and I'm outta luck for the turbo if and when I have to do them on it.

 

bleh... that probably would have been better for me to pull off the cams... i had to physically open the valve with a standard screwdriver and then grab the disc with a magnet then grind it to spec and check with a micrometer and reinsert... i ended up doing 4 discs but it still wasn't fun to push open all the valves... if i had a proper tool rather than just a screwdriver i'm sure it would have been much easier. but the good thing is its over!

 

true enough, the tool (bought from chacal) is an indispensable tool ffor this job!

 

You ground your own 8O . I just bought new ones.

I hope you ground the side with the writing on it. Otherwise the next guy will get royally screwed when he reads those old values.

 

I found a local shop that will do it for a lot cheaper than the dealer. He said it was an easy task and charged a minimum fee to do so. I had some other work done but I believe the shimming itself cost me about 50 bucks. I didn't mind paying that to save me the trouble.

 

My local Yamaha dealer has an exchange program for shims. You just bring in ones you don't need then trade for the ones you do. Free! Of course, you do have to endure the kidding about the "giant" shims and the "let me see if we still have any of those *old* ones" remarks.

 

ya i was lucky enough that the only ones that needed adjusting were ultra tight so they could be fixed by grinding rather than getting a bigger shim. it was tedious task because i didn't want to take much off. i just touched it to the flat side of a bench grinder with a fine wheel. after I got it to the desired fit i measured it with a micrometer and marked it with an etcher (on the down side of course) and so i'll remember next time! hopefully there won't be a next time for a long time though!

 

You realize that grinding corrupts the "hardness" of the shim, as the rockwell treatment that "hardens" the metal only extends a few microns past the surface.......!!!

 

My Haynes manual says valve clearances should be checked and fixed every 6 months. I haven't had my bike that long so don't know how quickly they change. How frequently to others check / fix clearances?

 

Most people never do it, which is a problem. They don't do it because it's a big pain in the hard-tail.

Yamaha recommends checking them every 5000 miles/8000 kms or yearly. I think on the 900 models, the clearance check interval is a little longer, like every 7500 miles.

BTW, if you don't check and adjust the valve clearances, you're "basically" wasting your time synching the carbs and/or colortuning them............

 

when the mileage is low, or after the bike sat for a long time, the clearances will change more dramatically as the valves wear in to the seats. usually the clearances will get tighter, and would require a thinner shim. alternately, as the cam lobes wear, the clearances might increase, requiring a thicker shim.


if you don't know the state of the shims, I'd recommend at least checking them.

too tight = really not good - could burn a valve, since they're not closing all the way.
too loose = not as bad, but still not good...

I found that the most annoying part is to get the damn valve cover gasket to seal up afterwards. Checking the clearances is easy.... A cheap feeler gauge does just fine.

there's a thread somewhere that describes the use of a folded zip tie instead of the valve retention tool (which can crack the head if you're not careful). I've used this method on both of my bikes, without any problems. also, the shim buckets can be rotated so it's easier to get to that little notch where you can pry the shim out.

 

I just came back in from checking my valve clearances. It looked to be an extensive project and I figured I'd be in the shop for the remainder of the day, but, they are all in specs!! The valves haven't wore a bit. It could be the fact that I use synthetic oil?
The dealer next door (motorcross and snowmobile dealer) has the tool, but I didn't even have to go get it. Now after the paint dries on my valve cover, it can go back on.
The gasket I won off Ebay Monday, came today by UPS, so things are looking up! After the paint dries on the valve cover, I can put things back together. PD

 

thats okay i cast a hardening spell on them :lol: just kidding. hopefully it doesn't matter too much because thats what i was told to do by a veteran yamaha race car builder... (yes i do realize i said yamaha and car in the same sentence.) we'll see how it ends up and i'll let you guys know

 

I know this will make RickCoMatic and possibly a few others shudder,but I have knocked a touch off valve stems rather then trying to lap down the shims

 

as long as your willing to accept the consequences do whatever you want.

 

Yamaha race car??? Tell us more!

 

actually there is no consequenses if you know what your doing and have correct tools, valve stems should be touched up when grinding valves to resquare and eliminate any pitting and scoring

 

perhaps i gave the wrong impression... its a yamaha powered race car it has the engine from a mid-eighties FJ1200 similar in many ways to the XJ bikes just bigger mostly.

they're generally called 'legend cars'

http://www.circletrackracingnews.com/wp ... stom-2.jpg

they're a bastardized yamaha motorcycle, toyata car, and 30's ford.... pretty lame if you ask me but it was always fun to work on them with him. now he's moved up a bit (or gotten more money ) and he's racing an A/C cobra

you can see a dumb video of it here

http://www.youtube.com/watch?v=7YjyGqcxitc

 

"Can't be done!" I love when people tell me that. It just makes me prove the wrong. Some just think because the book says that's the way, isn't always the ONLY way. PD

 

I am about to tear in to the valve cover myself and check/adjust clearances. I've never done that but I have studied up on it, and understand it. I ordered feeler gauges on ebay. Im still looking for a valve shim tool (Chacal PM me a quote if you have one) and I know Im going to need a new cover gasket. Also where is the best place to get shims?

 

Some have stated that Yamaha dealers might have them discs and will just exchange the new size ones for yours. I was fortunate enough not to need any, so I don't know if they do here or not. The tool would come in handy. I was about to make my own untill I found out I didn't need one this time, but I will need to get (or make) one eventually.

 

Energi2er....you got mail!

 

hummm i always like checking and ajusting valves always makes me feel closer to my bike.

 

This is a project I will soon tear into as well and am dreading. I have a manual on cd, can't remember which one. I hope it tells me and I understand but I wouldn't know what my goal even is. I mean with the shims and clearance and what not. I have no idea what ideal or out to lunch looks like. But I'll guess I'll find out.

Also I need to take off the head as I'm certain that I have a leaking head gasket. That brings more worries with the timing chain and what have you. But I'll save that for another thread coming soon.

 

hmmm i wouldn't fret the valve shimming... i made it sound alot worse than it was but it was the single most beneficial thing i've done for my bike so far... so the moral of the story is GO OUT AND DO IT! 'just take your time and you'll be sitting pretty. it also helps to have a micrometer but you absolutely must have a set of feeler gauges.

 

I'm 'bout to do mine on the Maxim, just have to figure out a way to get the shims out. Like a dumba$$ I measured the clearance but didn't plan far enough ahead to be able to take out the shims and measure them. As the clearances turned out, about half my valves are out of spec on the tight side. It seems my valve seats wore faster than my shim/cam did. Ahh, a fun job for spring.

As far as grinding on the shim, I would be less concerned with grinding off the case hardening and more concerned with making sure the shim is ground flat, i.e., both sides are parallel to each other. Think about it--if you grind a taper into your shim, one end of the lobe or the other will take all that load and possibly lead to premature wear. You'd have a corner/edge of the cam lobe bearing down on the face of the shim, rather than the whole face of the cam lobe.

This is assuming, of course, that the ground side goes DOWN (into the bucket) and does not face the cam. The hardness is there to reduce wear between the cam lobe and the shim. Case hardening doesn't do much of anything between the shim and the bucket.

I just realized I'm assuming the bucket/shim setup here is the same as it was on my Fiat, so maybe the Yamahas are different. But I'll just assume they're the same until I get in there and/or read the manual more closely :wink:

 

if your careful, and have a micrometer lol, you can make sure that your pretty dang close to flat. i did mine using a magnet and the side of a grinding wheel and i just went really slow and let the shim spin on the magnet as the wheel took off tiny bits at a time and after checked it with the mic' and they're perfect.... i'm not worrying about it. and yes i did face the ground side down.

 

Guys! You know that replacement shims aren't very expensive, $ 7.50 each or less in sets of 5.........between being able to swap around some shims and the typical wear patterns, it's unlikely that any engine will need more than 5 new-sized shims.....why take the risk of re-grinding old shims, and either messing things up or causing more wear and more future valve adjustments in the future?

 

your right chacal and if i do it again i'll probably order them from you but i like the sense of accomplishment i get from doing it myself... i'm sure you can appreciate that

 

Men:

You don't grind shims!
You get the right Shim and install it without trying to machine anything.

If you dont have the Shim tool ... and it requires a "Special Shim Tool" to do the 750 ... because the Shim Tool I have that works for 650 and 900 won't do a 750 ... you can loosen the Cam Bearing Caps and lift the Cam.

Caution:
Don't remove the Cam Caps.
If you remove the Cam Caps and the Camshaft "Gets away and rotates forward ... the Automatic Cam Chain Tensioner will immediately take-up the slack and make it impossible to place the Cam back in the Bearings.

This situation will involve removing the Cam Chain Tensioner and doing a Manual reset of the Cam Chain Tensioner.

A proper reset of the Cam Chain Tensioner is going to involve making a Gasket.
Adding sealant
Reinstalling the un-loaded Cam Chain Tensioner.

A job that ... unless you have the strength of a God, is going to involve removing the Carbs to get the Bolt Cap on the end of the tensioner ... working against the two spring within a spring tensioner springs.

 

So in a shim exchange program, everyone assumes that the shims don't wear at all, and remain square.
So why don't we do a shim exchange program thru XJBikes ???

except for those that already ground their shims, and ruined them.
Someone could ask $3.00 per shim and make a killin !

Plus postage.

 

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!