Servicing - valve clearances

[abraxas]

The last service i paid the dealer to do. I know for a fact he didn't do it properly.
I have the manual and it's a very long list of things to do, including valves.

How crucial is this? I am on 60 000km so perhaps it's time?

Any advice appreciated ....

 

[Raid The Revenge]

After 40,000 KM you should perform a valve clearance procedure. This is a very important task, because if the clearances aren't within standard those valves could come into direct contact with the piston! Or the air-fuel ratio will be disrupted!

Remember that there are 4 pistons and 16 valves in an FZ6 engine. Can you imagine what would happen if all those valves and pistons were working out of alignment? Your timing would be ruined! We're talking lost compression, poor air-fuel mixtures, excessive exhaust and extra wear.

Valve clearance jobs are very expensive. I know people who've had bent valves and ill engines because they didn't perform this task. It's not dreadfully difficult, but there are lots of steps involved. If your dealer didn't do the job properly, why are you letting him get away with it?? It's a very important job! It would be the last thing I'd want to go wrong.

 

[Guitar Man]

I'm planning on doing mine next week at the regular scheduled interval. I would not put it off much longer. If your valve clearance goes to zero you could have some serious engine problems. The valves wear in and loose some of their clearance and that is why you need them checked at 26,600mi. If you are mechanically inclined just follow the manual step by step. If you don't think you can do it find a reputable shop that will do it for you. Better to pay a little now than a lot later.

 

[chemicalsmile]

There's a pretty nice write-up with links to pics here

 

[wolfc70]

After 40,000 KM you should perform a valve clearance procedure. This is a very important task, because if the clearances aren't within standard those valves could come into direct contact with the piston! Or the air-fuel ratio will be disrupted!

Remember that there are 4 pistons and 16 valves in an FZ6 engine. Can you imagine what would happen if all those valves and pistons were working out of alignment? Your timing would be ruined! We're talking lost compression, poor air-fuel mixtures, excessive exhaust and extra wear.

Valve clearance jobs are very expensive. I know people who've had bent valves and ill engines because they didn't perform this task. It's not dreadfully difficult, but there are lots of steps involved. If your dealer didn't do the job properly, why are you letting him get away with it?? It's a very important job! It would be the last thing I'd want to go wrong.

Usually it is not that severe. As the vlaves slam shut over time the clearance between the camshaft and the adjuster can become too tight, allowing the valve to not fully seat and you loose compression and power. If this scenario goes on long enough, you can burn a valve.

The other thing is that the clearance between the cam lobe and the adjuster (in this bike it is an inverted bucket with shims) can become larger, then your valves are just noisey, as no damage will occur with this scenario.

Most likely at the 26,000 mile mark, no adjustment is going to be needed, but checking the clearances is easy and is well worth the time to do it. Just mark down the clearances of all 16 valves and only replace the ones out of spec. Most bike makers say tou need to pull the cams to remove the shims, but sometimes you can sneak the shims out past the cam lobe. Just buy the bucket tool from the dealer to release the shims. You can do it with a scewdriver, but you have a better chance of scratching a wear surface doing it that way.

Unless something severly wrong with the cam timing, the valves are not going to hit the piston. Below is a picture of how to measure the clearance. Yes it is on a V twin, but the idea is the same on all mechanical tappet engines.

 

[The Rayman]

There's a pretty nice write-up with links to pics here

It is quite involved for sure. I've read that a lot of folks who checked them said they were in spec way after the recommended interval. Anyone here find theirs out of spec?

 

[Fred]

After 40,000 KM you should perform a valve clearance procedure. This is a very important task, because if the clearances aren't within standard those valves could come into direct contact with the piston! Or the air-fuel ratio will be disrupted!

All of the above information is wrong.

The interval is 16,000 miles, which is 25,759 kilometers.
http://www.mcnews.com/mcnews/articles/200403-599vsFZ603.pdf

EDIT: My numbers on the interval are wrong. That's what I get for trusting the internet.

The valves will not hit the pistons.

The air fuel ratio will not be disrupted.

What will happen.

If valve clearances alter, your throttle bodies will be out of synch. The engine may have more vibration than normal. You won't know it until you've set things back to ideal, because the vibration would have snuck up on you over thousands of miles.

The valve clearances will slowly close up. As the clearances close, the time the valve is open increases. This isn't a good thing, because it's opening earlier and closing later. It's not going to cause the valves to hit the pistons, but it is throwing your valve timing away from optimal.

Second, the valves are in contact with the valve seats for less time. They shed heat through the seat, so they will get hotter. Eventually you can burn valves from this, and the valve face can break off of the stem in a worst case scenario. At which point the broken off part of the valve can hit the piston. You'd have to REALLY neglect the bike for this to happen.

The FZ6 has a shim under bucket valvetrain. What this means in plain english is that the valve clearance will rarely change. It's a very good system.

When you check the clearance at 16000 miles, write down the clearances and any changes needed. Save this data. Look at it during the next check and the one after. It's likely that you'll see the valves aren't changing their clearances after the first adjustment. They've settled in and will be good for a long, long time.

What Elm is thinking of is a broken cam chain. In this scenario, the valves stop (some of them still open) and the pistons keep moving. And that does bend valves. That's a totally different scenario and is unaffected by valve adjustments.

Fred

 

[Raid The Revenge]

All of the above information is wrong.

The interval is 16,000 miles, which is 25,759 kilometers.
http://www.mcnews.com/mcnews/articles/200403-599vsFZ603.pdf

--The HAYNES manual says every 40,000 KM in EUROPE, every 42,000 KM in the US.

The valves will not hit the pistons.

--You're right. The pistons will hit the valves instead.

The air fuel ratio will not be disrupted.

--So you're saying there will be NO LOST POWER?? With incorrect shim measurements???

What will happen.

If valve clearances alter, your throttle bodies will be out of synch. The engine may have more vibration than normal. You won't know it until you've set things back to ideal, because the vibration would have snuck up on you over thousands of miles.

The valve clearances will slowly close up. As the clearances close, the time the valve is open increases. This isn't a good thing, because it's opening earlier and closing later. It's not going to cause the valves to hit the pistons, but it is throwing your valve timing away from optimal.

Second, the valves are in contact with the valve seats for less time. They shed heat through the seat, so they will get hotter. Eventually you can burn valves from this, and the valve face can break off of the stem in a worst case scenario. At which point the broken off part of the valve can hit the piston. You'd have to REALLY neglect the bike for this to happen.

--Hmmmm.....sounds like something that happened to TWO people I know, THREE if you count myself. We didn't neglect our engines.

The FZ6 has a shim under bucket valvetrain. What this means in plain english is that the valve clearance will rarely change. It's a very good system.

--True.

When you check the clearance at 16000 miles, write down the clearances and any changes needed. Save this data. Look at it during the next check and the one after. It's likely that you'll see the valves aren't changing their clearances after the first adjustment. They've settled in and will be good for a long, long time.

What Elm is thinking of is a broken cam chain. In this scenario, the valves stop (some of them still open) and the pistons keep moving. And that does bend valves. That's a totally different scenario and is unaffected by valve adjustments.

Fred

..........I'm getting tired of this. Now I can see why Raid the Revenge took off from this place.

 

[Fred]

Most bike makers say tou need to pull the cams to remove the shims, but sometimes you can sneak the shims out past the cam lobe. Just buy the bucket tool from the dealer to release the shims. You can do it with a scewdriver, but you have a better chance of scratching a wear surface doing it that way.

Good info, Wolf. I saw your response after I wrote mine.

I've done the valve shims on my K-75 the way you describe. Given a set of picks and a tool to hold the valve open, the shim can be pulled out easily.

Unfortunately on the FZ6 it is necessary to pull the camshafts. Instead of being on top of the bucket like in the picture you posted, the shim is underneath it. This setup is even more stable than the shim over bucket setup that your pic and my K-75 have. But it's a pain in the butt to change the shims.

On the other hand, old school pushrod valves with screw adjusters are very easy to adjust, but you have to do it more often. Win some, lose some.

 

[poorwboy]

..........I'm getting tired of this. Now I can see why Raid the Revenge took off from this place.

HUH.

 

[Fred]

I was wrong on the numbers. Ignore that link I posted for the valve interval, it's incorrect.

I stand by the rest of it.

Out of adjustment valves won't hit the pistons.

Power will be lost. Not because of mixture problems, but because the valve timing is no longer optimal. The engine isn't pumping as much air anymore.

The EFI computer will see less airflow (higher MAP sensor reading for the FZ6) and compensate. So the mixture won't go off due to valve adjustment issues.

 

[abraxas]

Thanks guys .... excellent comments.

I spoke with the local yamaha mechanic and this is what he said.

It is very important to check them, the consequences are very sever. However, he has not had to do shims on a yamaha for many years.

They don't shift .... (apparently) ..... So i'll take some time soon, and get into it, it does seem like a helluva job though ...

 

[aussiejules]

Putting the shims under the buckets doesnt make them wear less, the reason for it is to allow the engine to rev higher without the worry of the shims shifting out and doing damage. In toyota's most were above the buckets but in the mr2 and the v8 cruiser which rev higher and work harder they went under, as to with alfa's, which are a very high revver the shims are under the buckets.

 

[abraxas]

So i had to take the head for for something else ....

Busy re-assembling, and cannot get the damned timing right?

At first i thought i was 1 tooth out, took apart, fixed that, no good. The camshaft timing marks are opposite each other, level with the top of the head, and the crack mark is level with the mark on the crank housing.

The bike doesn't run when started, it whines. I can only think i got something wrong, but so far as i know did everything by the book. What did i miss?

peace

 

[Cali rider]

So i had to take the head for for something else ....

Busy re-assembling, and cannot get the damned timing right?

At first i thought i was 1 tooth out, took apart, fixed that, no good. The camshaft timing marks are opposite each other, level with the top of the head, and the crack mark is level with the mark on the crank housing.

The bike doesn't run when started, it whines. I can only think i got something wrong, but so far as i know did everything by the book. What did i miss?

peace

Just recheck a couple of items:

- Are the intake and exhaust cams AND sprockets in the correct locations? If you somehow put the wrong part in the wrong side (intake sprocket on exhaust cam, exhaust cam on intake bearing, etc.) it would not run.

- Is the cam chain correctly timed and tensioned?

- Are the spark plugs installed?

 

[abraxas]

Cali Rider thanks.
Despite keeping all the parts in a straight line, i suspect the cams got swapped somewhere, trying that

Your signature line makes me cringe today!!

I'm not doing well with this job

 

[abraxas]

Cam marks are:

- I intake cam Exhaust cam E -

Level with the top of the head., opposite each other.


-T Crank
Level with the mark on the crank housing.

This is right? Right?

The engine turns by hands, no valves broken, valve clearances good. Got fuel, and spark and air. But when i turn the engine i get compression OUT the intakes ...

 

[FinalImpact]

I'm tired and logging off but here are some "general tips" which are easy to follow and see with your eyes.

With the number one Cylinder, make sure its at top dead center (piston all the way up at the top of its bore). You can see it! Now look at the crank and align the mark to the alignment spot for TDC.

For the engine to run the Cam timing should have both of the intake and exhaust valves closed on the #1 cylinder. Meaning the lobs should be pointed up away from the valves. With the lobes up and the Crank on #1, align all the marks, fit the cam and chain into place. If you rotate the engine 720 degrees, all of the marks should align again.

Do your magic and tell us what you get.

 

[abraxas]

The lobes are the thing.
They aren't facing away from the piston, they're sideways, although both are opposite each other.

720 degs keeps the same formation. Crank 360 moves the marks to meet each other on the inside.

 

[abraxas]

I need a favour from anyone.

Section 5.15 in the manual, cam timing.

Please look at th position of the lobes, intake lobe (1) is facing to the left, next to the timing mark.

Surely that is wrong? Because according to that pic, the exhaust valve opens first? We are looking at cylinder 1, with the firing order 1-3-4-2. The crank turns twice for every turn of the camshafts. Crank cycle 1 intake opens, crank cycle 2 exhaust opens?

So what i see is intake cam ready to open at tdc, crank cycle 1, with the exhaust opening on crank cycle 2. So what i see is NOT what i see in the manual, with regards lobe positions?