Confused about valve adjustment procedures

[Guest]

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.

 

[Guest]

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

 

[Guest]

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.

 

[Guest]

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.

 

[gearhead13]

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"

From what I know from the automotive world, hydraulic adjusters cannot be used at high rpms that our bikes run at. The adjusters tend to "pump up" leaving the valves to not fully close at high rpm. Ok for a lumbering vtwin but not a gs or gsxr running 10k rpm or higher.

 

[Nessism]

From what I know from the automotive world, hydraulic adjusters cannot be used at high rpms that our bikes run at. The adjusters tend to "pump up" leaving the valves to not fully close at high rpm. Ok for a lumbering vtwin but not a gs or gsxr running 10k rpm or higher.

??? Did you not read the caption in the photo?