Valve adjustment - more lessons learned

[markjenn]

What does the typical dealer charge to do the valve check/adjustment?

Varies widely. Some flat rate charge a single fee regardless of actual work required, others flat rate charge at two different rates depending on whether an adjustment is required, others bill at actual time spent. I'd guess $300 to $800 is the general range, but it could go even higher. I'd be cautious about dealers charging a single flat rate (especially if it is low) as this results in a huge incentive for the mechanic to let out-of-spec clearances slide by as "close enough". A $300 valve adjustment where out-of-spec valves are ignored isn't any bargain.

Does it need to be done by a dealer to maintain YES warranty coverage?

No, but for a warranty claim involving the valve train it is likely Yamaha will require you to provide documentation that that work was done at the appropriate mileage. This documentation can be a work order from a independent mechanic or even your own notes/receipts if you do the work yourself, but the more "shade tree" your documentation, the more likely Yamaha is to push back and blame the warranty failure on poor maintenance. So having a Yamaha dealer do the work is the safest bet. Speaking practically, this is a job that has huge opportunity for catastrophe and requires good mechanics skills so your skills/tools either need to be up to snuff or you need to use a very competent shop.

- Mark

 

[SC116]

Hi MGB:

This is a great post - I appreciate the structure as a personal note with lots of detail.

To the group: If you have a valve that requires adjustment; that is to say that one or more are out of the specification range altogether - especially on the tight side of any shim-and-bucket or inverted shim-and-bucket system, this is usually a symptom of another issue such as a recessed or otherwise damaged seat, a mashed bucket, a mushroomed valve, etc.

If one or more of the valves are critically out of adjustment, the Engine MIL would most likely be illuminated and DTC(s) would probably be logged due to an unbalanced/irregular air-fuel mixture that the oxygen sensors are working overtime to correct. i.e. - fuel trim out of whack. Rough or otherwise irregular idle quality would also be a probability, but acceleration or other engine performance issues would be unlikely.

If the observed valve clearance is within the specified range - not too close to tight or overly loose, I would consider a judgment of "close enough" by a trained professional to be of great value. I would suggest that just such a judgment is a reasonably complete assessment of the valve train. This suggests that the cams, valves, seats, buckets, and cylinder head line bores are in good condition. Further disassembly to adjust fractional millimeters within an already-achieved specification window may invite additional problems.

What I'm talking about here are the laws of unintended consequences...if it ain't broke, don't fix it.

Please don't misunderstand me - given my technical background, I'll be the last to discourage quasi-neurotic maintenance habits and/or advanced diagnostic techniques. I'd lay odds that I'm the most guilty party of all said practices.

If minor adjustment is required, going on the loose side is advisable. My method for the past thirty-plus years has always been to insure that the metric tolerance gauge at the maximum end of the specification range will comfortably breach the air gap, but that the next-highest SAE gauge will not. Despite the long-winded intro, that's my two cents...

I apologize if I've bored any of you or if I've gone over the top in terms of detail.

Thanks for the great post and for stimulating thought. And thanks to everyone here for the valuable advice and for embracing the free exchange of information.

Cheers!

 

[markjenn]

To the group: If you have a valve that requires adjustment; that is to say that one or more are out of the specification range altogether - especially on the tight side of any shim-and-bucket or inverted shim-and-bucket system, this is usually a symptom of another issue such as a recessed or otherwise damaged seat, a mashed bucket, a mushroomed valve, etc.

Sorry, but this is complete BS. Valves do go out of adjustment due to ordinary "wear and tear" which has absolutely nothing to do with things like damaged seats, mashed bucket (???), or mushroomed valves.

The valve clearance specification is Yamaha's rather arbitrary judgment about the appropriate clearance that provides normal engine operation and normal valve train life. Clearances change over time as an engine wears. Typically the clearances decrease as the valve seat is the area of most wear, but it can go the other way if cam wear, rocker wear, etc. predominate. It is not unusual for a high-mileage engine to require several valve adjustments but otherwise have a normal service life.

As clearances decrease, valve temps go up as the valve spends less time transferring heat away from the valve to the head and if the clearance goes to zero, then you start losing compression and the valve temp goes up dramatically which can quickly lead to complete failure. (This is commonly referred to as a "burned valve".) As clearance increases, the valve tends to make more noise as the cam no longer is able to smoothly lift the valve off the seat - it tends to "slam" the valve open abruptly which increases stress on the valve. The engine also starts to lose power simply because the valves don't get opened as far as they should.

There is no need to make this more complicated than it needs to be. Respecting that Yamaha is probably in the best position to make judgment calls like this, check the clearances around when Yamaha recommends, but don't get terribly excited if you are a somewhat early or late - do it when convenient and when the bike is down for other maintenance. If the valves are within the spec'ed clearances LEAVE THEM ALONE - there is no need to screw around shimming a valve at the "lose end of spec" and it is virtually impossible to do so anyway since the the shims come in increments that are nearly the entire spec range. If all the valves are within spec, LEAVE THE ENGINE ALONE and count yourself lucky that you don't have get into the hassles of pulling cams. If one or more are not within spec, then bite the bullet and do the job - CAREFULLY. Checking valves is a hassle but well within most hack mechanics abilities; adjusting them is a tricky stuff that requires one's A game.

- Mark

 

[Checkswrecks]

Agree with Mark on this. Keep somewhat close to Yamaha's schedule and tolerances and you'll be fine.


btw - It will almost always be the exhaust valves which go out of spec. They are the ones with the hot exhaust gasses blowing thru and erode much faster than intake valves will. As the face/seat erode, there is less clearance at the bucket/shim/cam, so they are the ones which get tighter over time.

 

[RED CAT]

Worst part of the Valve Adjust is the Cam Chain Tensioner, especially the Gen 2 bike. Have fun.

 

[Pterodactyl]

Checked my valves today for the first time at 19,000 miles. One exhaust valve was at 0.20mm (0.02mm too tight). All other valves are at least 0.02mm above minimum tolerance. I've done the valves on many BMWs and my FJR and none were more finicky to get to. I anticipate getting the valve cover on with the gasket properly aligned will be a pain.

I wonder what tolerance Yamaha shoots for at the factory. From my limited experience, it does not seem they target getting the valves set in the upper half of the tolerance range as I wish they did.

 

[Pterodactyl]

I adjusted my rogue valve yesterday. I was able to extract the bucket and shim without completely removing the exhaust cam or loosening the intake cam at all. After zip tieing the cam chain to both sprockets and the timing wheel as well as making witness marks on the sprockets and chain, I was able to lift the cam and move it forward enough to go my business. I've used this technique on my FJR a few times.

 

[WJBertrand]

I adjusted my rogue valve yesterday. I was able to extract the bucket and shim without completely removing the exhaust cam or loosening the intake cam at all. After zip tieing the cam chain to both sprockets and the timing wheel as well as making witness marks on the sprockets and chain, I was able to lift the cam and move it forward enough to go my business. I've used this technique on my FJR a few times.

Great tip. Do you think you could access any of the exhaust (or even intake for that matter) this way?

 

[Pterodactyl]

I did just the inboard exhaust valve on the #1 cylinder. I'm confident that one could do the three exhaust and intake valves that are the farthest from the sprockets without difficulty. Not so sure one could do the outboard valves on the #2 cylinder, but maybe. I did all 16 valves on my FJR without removing a cam.

 

[Mellow]

I adjusted my rogue valve yesterday. I was able to extract the bucket and shim without completely removing the exhaust cam or loosening the intake cam at all. After zip tieing the cam chain to both sprockets and the timing wheel as well as making witness marks on the sprockets and chain, I was able to lift the cam and move it forward enough to go my business. I've used this technique on my FJR a few times.

That's an excellent tip if you only need to mess with all but the right-most buckets near the sprockets... wouldn't have worked for me as I had to do all 4 of my exhaust valves but will definitely keep it in mind next time.

 

[holligl]

Just turned over 26k today. I had planned on valve check at the next oil change targeted at 26,600. After discussion with a high mileage forum member (mechanic) on his 2nd Tenere, I am considering delaying until winter. It would probably go over 30k with the delay. While I don't have a comparison, it seems like the bike's running fine. Any real risk in going an extra 4k!

 

[snakebitten]

Shhhhhhh.

Don't talk too loud. Maybe your valves won't know. And hopefully they can't read. (the owners manual)

Just messing with ya.

But seriously, relax. Have fun for 4000 more miles.

I changed the oil in my truck today while on my cross country "escape the Texas heat" adventure. While at it, I found my air filter was dirtier than expected. And get this, about 2000 miles before it's called to be replaced. I put a fresh one in. But would if I didn't?

Truck was running perfectly fine before I checked it. And I promise you I couldn't tell the difference with the new one.

And finally........more Teneres have suffered maladies from folks messing with the valves (perhaps unintentionally) than folks ignoring their valves.
In fact, I don't ever remember a single report of Tenere trouble from unadjusted valves.

 

[2daMax]

I sort of remembered a high mileage Tenere having a hard starting and was due to valve clearance, well negative clearance I suppose.

 

[Checkswrecks]

I sort of remembered a high mileage Tenere having a hard starting and was due to valve clearance, well negative clearance I suppose.

::026::

 

[WJBertrand]

I adjusted my rogue valve yesterday. I was able to extract the bucket and shim without completely removing the exhaust cam or loosening the intake cam at all. After zip tieing the cam chain to both sprockets and the timing wheel as well as making witness marks on the sprockets and chain, I was able to lift the cam and move it forward enough to go my business. I've used this technique on my FJR a few times.

Just thought of another question since this thread popped up again. Did you have to remove the cam chain tensioner when you did this?

 

[eemsreno]

Just turned over 26k today. I had planned on valve check at the next oil change targeted at 26,600. After discussion with a high mileage forum member (mechanic) on his 2nd Tenere, I am considering delaying until winter. It would probably go over 30k with the delay. While I don't have a comparison, it seems like the bike's running fine. Any real risk in going an extra 4k!

holligl
Why don't you just come out and not beat around the bush,
You talked to some bum that only wants to go riding and not work for a living.
You need to be asking more reliable folk.

 

[holligl]

holligl
Why don't you just come out and not beat around the bush,
You talked to some bum that only wants to go riding and not work for a living.
You need to be asking more reliable folk.

I wasn't going to quote you without your permission! I'm just going to keep riding until winter. Planning to ride back to Iowa sometime this fall to help my brother with the crops. Hope to look you up to go for a ride.

 

[snakebitten]

I wasn't going to quote you without your permission! I'm just going to keep riding until winter. Planning to ride back to Iowa sometime this fall to help my brother with the crops. Hope to look you up to go for a ride.

Until I read your response to eemsreno, I coulda swore he was describing ME!

Accurately too! (bum, only wants to play, rather not work. Unreliable advisor)

 

[snakebitten]

I sort of remembered a high mileage Tenere having a hard starting and was due to valve clearance, well negative clearance I suppose.

Touché

But, as you pointed out, "high mileage"......so not really applicable to holligl.
And even the example bike suffered no serious calamity.

And finally, Hey Bob, I saw you pile on! I'll get ya when ya least expect it. 8)

 

[steve68steve]

I just put my 2014 back together and it started it up with lots of clatter. I hoped that it was just oil not being fully distributed thru the top end. I took a short ride and the clatter was intermittent - my spidey sense is tingling that something is wrong with my timing chain.


I had the exhaust camshaft out, but never removed the intake shaft. To get the chain installed and marks aligned, I made a spanner to rotate the intake cam forward. I got everything aligned, and then I stuck my finger in the tensioner hole to confirm I was feeling guide and not chain. Not feeling chain, I put the tensioner back in. It seemed like I had resistance when installing it (I assume spring tension, that maybe it had accidentally deployed). When I got back to the clutch side, I seemed like there was little (no) slack in the chain, and I couldn't push the guide over to release the tensioner - the guide was already contacting the chain, it looked "good". I assumed this meant the tensioner got bumped enough to have already deployed. I turned the engine over a bunch of times with a wrench to confirm everything was moving right and alignment marks were where they should be and it felt exactly like how it felt turning over by hand to find the alignment marks before I had anything apart.




But then there's this clatter, and I read the "valve adjustment gone horribly wrong" thread.


So now I think I should pull the clutch cover, zip tie up the chain near the drive sprocket, pull the tensioner, and see what happens. If the tensioner is not deployed, that'll be the smoking gun the chain is twisted around the guide. If the tensioner is deployed and has and grinding marks on it, that would confirm the "valve adjust gone horribly wrong" diagnosis.
If everything looks good, I'm at a loss to explain the clatter.