Confused about valve adjustment procedures

[Nessism]

We got into this long discussion over at KZ Rider about the best way to position the cams, and needless to say there wasn't a consensus.

I checked the valves on my KZ three different ways and took the measurements. Bottom line, the Suzuki method results in the tightest measurements, which is perfectly appropriate on GS's because the lash spec is tight. The 180* positioning method resulted in the greatest clearances, and that frankly is good enough for KZ bikes because the lash spec is quite a bit wider than GS's. I'd say that the 180* method could be used for GS's as well, but I'd bump the spec range up from .03-.08mm to .06-.11mm. Kawasaki's spec is .05-.15mm.

[BoCoMoMann]

That GS1100E is a 16-valve engine that uses a different procedure for checking clearances.

I will repeat what others are saying, which is what the Suzuki manual is saying, but will use some slightly different words.

The manual tells you to position the lobes in a certain way, but the picture they give you is not very clear. For the exhaust (I usually start with 1 and 2), E1 lobe will point FORWARD, E2 lobe will point UP. While those two lobes are in that position, neither one is pushing on its valve and are still both on the base circle, so they are not skewing that side of the cam in its bearing. While those lobes are in that position, measure BOTH, E1 and E2.

Now rotate the crank 180 degrees (1/2 turn), you will find that Intake 1 is pointing UP and Intake 2 is pointing BACKWARD. Measure BOTH, I1 and I2.

Rotate the crank another 180 degrees, you will see that E4 is FORWARD, E3 is UP. Measure BOTH, E3 and E4.

Rotate the crank a final 180 degrees, you will see that I4 is UP and I3 is BACKWARD. Measure BOTH, I3 and I4.

The concept is not hard, once you grasp the idea that both cam lobes are pointing away from their valves at about 45 degrees, so are not pushing on them at all. I believe the factory manual is the only one that uses the words "measure both valves", neither Clymer or Haynes mentions that, they only show an end view of a cam with two lobes and say something to the effect of "use this position", but doesn't say for which valves.

And, BoCoMoMann, if you insist on using your way to adjust the valves, I will respectfully avoid your shop.

EDIT: I just took another look at the picture you posted of the manual. Look in the right-side column, item number 1.

I added the bold for emphasis, but there it is, in your own factory manual.

.

Uh, yes, I posted the manual page with the hope that you might understand I know what you are talking about.

It's only applicable to a few bikes -

It's not a big deal and blinders I wear not.

How again is all that applicable to the GS450 series?

And I quit working at powersports dealerships, mainly because certain people took all the fun out of it.

I'll never do that again, but I'll wrench on my own stuff all day long.

Thanks for the comments

[BoCoMoMann]

We got into this long discussion over at KZ Rider about the best way to position the cams, and needless to say there wasn't a consensus.

To me it is quite simple - and this is the only way I ever do it.

Refer to the FACTORY shop manual.

Follow THEIR instructions

Works every time

There are too many variables for any one generic method to work

Still, a far better discussion that which oil to use or if K&N filters really suck or not.

[Nessism]

To me it is quite simple - and this is the only way I ever do it.

Refer to the FACTORY shop manual.

Follow THEIR instructions

Works every time

There are too many variables for any one generic method to work

Still, a far better discussion that which oil to use or if K&N filters really suck or not.

The Kawasaki KZ factory method of positioning the cams results in inconsistent measurement results. By that I mean that on some of the valves the adjacent cam lobe is pushing up on the cam and for other valves it isn't. I prefer the Suzuki method since the adjacent valve is always on the base circle. At the end of the day it doesn't matter that much since as mentioned, the KZ bikes use a lot of valve lash. Can't say I'm inspired to follow their method though.

[BoCoMoMann]

The Kawasaki KZ factory method of positioning the cams results in inconsistent measurement results. By that I mean that on some of the valves the adjacent cam lobe is pushing up on the cam and for other valves it isn't. I prefer the Suzuki method since the adjacent valve is always on the base circle. At the end of the day it doesn't matter that much since as mentioned, the KZ bikes use a lot of valve lash. Can't say I'm inspired to follow their method though.

Kawasaki builds them to be fast - not to last.

At least that is what it always seems like.....

The first street bike I ever had - H1B

Fast (for the time), did not last.

[John Park]

It would be interesting to know the actual running clearances when the engine is hot. My guess is about .010 - .012 due to the head expanding much more than the valve and other steel parts. If so, there may be way more variation depending upon whether it's a hot day or cold and whether you're riding uphill or down than whichever method of assuring that there is an initial cold clearance.

Suzuki's specs seem to be a minimum plus .05mm which makes a lot of sense, but if the shims were in .1mm increments you can guess what the specs would be. If you believe that your valves are actually running at anything close to those numbers when you're out having fun, well…..

How much clearance do YOUR valves actually have at the top of a long hill in July? I don't know and don't care, but it's surely enough as long as I had some to start with.

[Ghostgs1]

I've been messing around with these old 8 valve, 4 and twin cylinder GS's since the late 70's and I agree with nessism and Steve on using these Suzuki manuals method. The first attempt I made at valve adjustment, I didn't have the manual and used the old hand rule of pointing the cam away from the valve, couldn't get repeatable clearance readings. When I began using the correct Suzuki method the problem went away. On the twins, either method appears to be fine. Ray

[Ghostgs1]

It would be interesting to know the actual running clearances when the engine is hot. My guess is about .010 - .012 due to the head expanding much more than the valve and other steel parts. If so, there may be way more variation depending upon whether it's a hot day or cold and whether you're riding uphill or down than whichever method of assuring that there is an initial cold clearance.

Suzuki's specs seem to be a minimum plus .05mm which makes a lot of sense, but if the shims were in .1mm increments you can guess what the specs would be. If you believe that your valves are actually running at anything close to those numbers when you're out having fun, well…..

How much clearance do YOUR valves actually have at the top of a long hill in July? I don't know and don't care, but it's surely enough as long as I had some to start with.

John, It is hard to guess what the differences might be, hot versus cold. I once had a 1973 Mercury Capri with the 2800 German Ford V6. When the timing gear failed, I elected to go through the valves also. When it came time to setting the valves, I hit a road block. The Manual gave settings for hot only, how do you get them hot when it couldn't run? I called Ford Engineering and they couldn't tell me, but they said to use the hot numbers. I did and then rechecked them later when hot, surprisingly they were the same. Maybe since the parts were all steel or cast iron I guess. I'd be very surprised if that was the case with a GS. Ray

[BoCoMoMann]

I always wondered why hydraulic valves were never a "standard" item on motorcycles, as they have become on automobiles.

• Cost?
• Oiling issues?
• Weight?

Honda had good luck with it on a couple of models, the VT1100 series has to be one of the lowest cost to maintain VTwins ever.

And the Nighthawk S demonstrated it could be used in a "hot rod"

[JJ]

John, It is hard to guess what the differences might be, hot versus cold. I once had a 1973 Mercury Capri with the 2800 German Ford V6...

I had a '77 Pinto-Stang with the 2800 V6. Absolutely one of the worst engines ever built.

[John Park]

I had a '77 Pinto-Stang with the 2800 V6. Absolutely one of the worst engines ever built.

Compared to the Chevy Vega engine it was a paragon of virtue. Thankfully, the pair are gone.

[BoCoMoMann]

Luckily my Capri had the 2000 OHC 4 with a boring but functional automatic.

Loved that car, it was wonderful.

Now I imagine it with that 2.3 EcoBoost engine and get all giddy......

[Nessism]

A lot of modern cars still use mechanical valve adjustment. The checking interval is pretty long though and/or the system is designed so that valve recession is offset by wear on certain valve train parts. My Nissan is that way as are most other Japanese cars. I think hydraulic lash adjusters are not the norm.

[JJ]

Compared to the Chevy Vega engine it was a paragon of virtue. Thankfully, the pair are gone.

Yeah... what engineering team would even consider aluminum cylinder walls, even if they were silicon-impregnated?

Bad move!

[BoCoMoMann]

A lot of modern cars still use mechanical valve adjustment. The checking interval is pretty long though and/or the system is designed so that valve recession is offset by wear on certain valve train parts. My Nissan is that way as are most other Japanese cars. I think hydraulic lash adjusters are not the norm.

When I worked at a shop, it was rare for a modern Honda to require valve adjustments. I remember one Honda 919 with over 60,000 miles and the valves were still all within specification.

Any of the major brands use such good quality metals and run exacting tolerances, you're right, they'll probably never need it.

Timing belts are another story.....

One of the dealerships I worked for carried every major brand, and it was pretty easy to tell which manufacturers cared about quality.

Honda, as arrogant as they are, tended to put out the best.
Yamaha came in a close second, followed by Suzuki and then Kawasaki.

Cam Am and Polaris I'll not even discuss.

OK fine, Polaris ATV's were the biggest pain to get parts for.

Sometimes there would be several revisions throughout the year on some models and the odds of getting the right part was next to impossible.

Try explaining that to a customer, guess who the bad guy always was -

I hope and pray to never again be in that industry in the position of service manager or writer, one of the most thankless job on the planet.

The letter one customer sent me was kept. His motor blew up on his Can Am Spyder and I was able to warranty it.

But those victories were few and far apart.

The best thing out of the whole experience was leaving with a heck of a tool box.

Which I hope to use for myself sooner rather than later.