This question's probably been asked before, but if so I can't find it using Search. I'm getting ready to check valve clearance for the fourth time (I know it's not necessary - it wasn't at 12K/20K/30K either).

Since I'm finishing my second week of no-smoking after 35years and am still a bit out-of-whack - some of you may know what I mean - I just wanted to confirm something that appears incorrect in the Shop Manual.

As I read the procedure it basically has you removing all cam chain tension then spinning the motor over from the crankshaft, which seems exceedingly stupid to me. It also has you doing something similar after replacing any shims and the cams - i.e. turn the motor over several times then remove the cam chain tensioner stopper tool.

As I recall, the first time I did the valve clearance check I followed the shop manual instructions without question or thought about what they said to do, until I got to the point where I started turning the motor over via the crankshaft and heard/felt the chain trying to jump on the crank gear.

If I'm off-base please advise, if not please confirm.

Thanks in advance.

Nice to hear from you! and good job on the no smoking! Won't hurt you with the enevitable weight gain either you thin waif.

Now on to the valves.

Yes it is correct they want you spinning the engine with the tensioner relaxed. I think it's to get correct clearance readings. If the chain has tension, it pulls the cams down which takes up the space the oil flows under pressure. (bearing clearance)

I've heard the sound, but it's not the chain trying to jump. It's the cam snapping forward from the valve spring tension, using up the little slack in the chain.

One thing I do is not bother turning the crank. I just put it in top gear and spin the engine with the rear wheel. Just have the cam lobe pointing away from the valve you're measureing.

Good to hear from you too Pete - I figured you'd likely be the one to reply. I do use the same technique to spin the motor - i.e. top cog and turn the wheel.

Not to start an argument, but I can't buy the reasoning behind the "loosen the chain tension" to accomodate the oil clearance angle. I think the oil clearance will be so small (.0008" -.0029") that the chance the tensioned cam chain will make a meaningful difference to valve lash when loading one end of the cams is remote. I wouldn't bet on whether or not the chain is trying to jump crank timing either. A small slip in the wrong direction could be quite expensive if it does.

I figure I'll continue checking clearance without releasing the chain tension, at least this time, while I do further research.

For what it's worth, the wrenches at the local Honda shop have no idea either, way which was expected. (When I first got the bike it would wobble severly at 55mph if you took your hands off the bars. Took it back since it was under warranty and after they said they all do that, took it home and adjusted the steering head bearings. Haven't been back since).

When I let Art read the shop manual directions without any prejudical prompting on my part, he came away with the same "wtf are they talking about" response that I had.

It makes an interesting discussion point at any rate and I look forward to hearing from you again. I'm in the process of finally doing all those things I've put off for 48K miles - changing all fluids, cleaning all electrial connections and new dielectric lube, etc.
Take care
Bill

The manual is written from an engineering perspective, not a real world perspective. Locking the CCT is merely a precursor to the post check step, which is to remove the camshaft.

The chain is not long enough (if its within spec) to jump teeth under workshop conditions. The tensioner doesn't keep it from falling off, just from slapping around.

Like Pete, I find it easiest to just turn the rear wheel.

My personal feeling is that if loosening the CCT will make a difference in valve clearance, I'll be buying a head...and maybe more in the foreseeable future. But I've no proof to the contrary...just my opinion, which is free.

Really appreciate the replies to this minor issue.

Regarding:
[The manual is written from an engineering perspective, not a real world perspective. Locking the CCT is merely a precursor to the post check step, which is to remove the camshaft.]

That's what I'd assumed, except that the manual also says to rotate the cams several times after reinstallation before you remove the stopper tool. Probably just another example of translating Japanese engineering-speak over to English do-it speak. Just made me wonder.

As I said in my earlier post, I agree turning the motor with the rear wheel is the way to go - its' worked fine for years and is by far the simplest way to do the job. I also agree with [My personal feeling is that if loosening the CCT will make a difference in valve clearance, I'll be buying a head...and maybe more in the foreseeable future.] probably is true.

I love this part:
This post is intended as an observation, opinion, and perhaps a different perspective. No intent to disparage, flame, or denounce another's integrity, intelligence, or sincerity in purpose exists in this missive. For a taped copy of this post, contact the manufacturer. All posts final. Void where prohibited. If you feel that you have read this post in error, return it in original packaging for immediate refund.

I must take time to learn how to properly work with the Avatars, HTML, etc. one of these days.

At any rate, thanks for the input and have a good day.

Bill

I hope washing her is also included. Really going for that "road dirt cammo look"

It's funny on that tensioner thing. Same damn thing was said on my V65. Which I religously relaxed to check it's valves for 70K miles. And they were screw and locknut! :roll:

Now I don't know.

You now want me to remove that protective coating I've been applying for the last several years? I'll at least give her the once over with a few "Scrubs" towellets and maybe a splash of wax where I can reach.

I did check with Art again for his opinion, just because inquiring minds want to know, and I figured since he's been a shop mechanic for nearly 30 years on Yamaha/Suzuki/Kawasaki/Honda/Ducati/ and now Harley (gasp) he should have an idea or two regarding this issue.

FWIW he's maintaining the books procedure is not how he would do the job, and that while you might get away with turning the motor over without tension on the chain, if even once it manages to jump a tooth on the sprocket due to a worn or out -of-spec chain, it isn't worth the chance. His procedure when you reinstall the tensioner is a little different too, in that he installs the tensioner as instructed in the book with regard to rotation/timing marks, then turns the engine backwards to push any remaining cam chain slack over to the intake side so the tensioner can eat it up. Oviously if the cam chain tensioner works from the exhaust side this would be reversed.

An interesting side note: I once ran my XS1100 with the intake cam off by 6 teeth for six months before I realized it (without causing any damage as luckily I must have been off in the "right" direction). Was running a 1220cc high compression setup and somehow blew it when I slapped it together. The motor made monster torque and I didn't realize I had a problem until I reinstalled a working tachometer and discovered the motor was only reving to about 6000 rmp max.