Bonneville America Forums Forums Technical Forums General Tech Cam Clearence's?

How concerned should I be about being a little over spec on the clearances?
I measured the following (in mm):
Left Cyl.: Left Exh: .28, Right Exh: .31; Left Int:.23, Right Int: .24
Right Cyl.: Left Exh: .33, Right Exh: .28; Left Int: .21, Right Int: .20
I know the specs call for: exh:.25-.30 and Int: .15-.20, but how critical is it for them the be .01-.03 mm (.0015 in.) over spec.? Is it worth pulling cams, etc. to replace shims?
I don't hear much "clatter", more cam chain whine than anything else.
Also, FYI... The bikes got a little over 28,000 miles on her. Previous owner put a 904 kit on her but don't what else he may done to the engine. When I got her, she had just over 15,000 miles.
Thanks!

It'll run better if you get the intakes back into spec. All in all, though, a wee bit loose is always better than a wee bit tight.

But in spec is best and advisable.

I don't want to hijack the thread, but this might help Larry and others.

I have always tried to set my clearances at mid range. Down in this wonderful land of Australia getting shims from a dealer is like trying to find rocking horse sh1t.

There is a company down in Victoria who actually make shims, but they are in increments of .05. So if you have an exhaust gap of .3 you either leave it or go down to .25. (which is the minimum) also knowing that we are not all engineers and our measurements could be a little out.

What would you do, knowing it would be out of spec very soon.

Good info on the Victorian company that does shims Frank. Do you have any more info on them - name, location, costs and whether they do mail order?
Thanks
JQ

I'll PM you the details.

I fully umderstand that if several people take measurements, you can can get several different results. Ambient temps, and just the "feel" can make the difference with tolerances that tight, and that's with the SAME set of feeler-gauges.
Our local Triumph shop has a good supply of the shims and are REAL good people. So with that, and the above comments, I guess I'll be seeing those guys. Especially, considering the trip I'm planning on taking this summer of 2,500 miles +/-, or so. As noted above, not knowing her history prior to 15K miles and now with 28,000 miles, she's due.

I just checked mine...

Exhaust (from left to right)
.25 .28 .26 .28

Intake (from left to right)
.20 .18 .18 .18

Not bad for a bike with 35,000 km and valves have never been done.

Question: Should I concern myself with the one .20 intake or just button it back up?

Personally I wouldn't bother Keith.(with my dificulty of getting shims) With the amount of wear we seam to get on these bikes you can do a lot more riding before you have to check again.

Like other people have said, better to be a little loose than to tight.

On the other hand as your riding season hasn't started yet, you could just change the one shim and know that you wont have to look again untill next year.

There are different schools of thought regarding valves.
Most say loose is better than tight. I wonder about this.
The biggest problem I see is that you don't know what the
original factory setting was, so you can't tell if things
went loose, or tight.

When I did my valve check/adjust I mined this site for info.
It's all here folks(I don't do Facebook). I learned from
the mistakes others made, and tried to avoid them myself.

After lengthy discussions with Bucky, I set mine to the
tight side of the range, for full valve extension.
I'll check 'em early next time, but think my bike runs
better than ever per butt dyno.
I saved all the specs, so I'll have a baseline next time.
Uncle Charlie

Like Unclecharlie, I set mine on the tight side. Usually clearances tighten up due to the valves hammering the seats but for some reason, these tend to loosen up over time. When I did mine last, they were very noisy on startup when warm. After the adjustment the valve clatter reduced dramatically.