Valve clearances at 20 degrees Farenheit?

[marshall]

Okay guys, next question.

I have a 1980 XS1100 (G) Midnight Special.

Today I got the valve cover off and checked valve clearances. Thing is, I'm in Ann Arbor, MI and my "garage" is a patch of dirt on the side of the parking lot in my back yard (it's okay, my neighbors already thought I was a redneck). It was something like 20 degrees out today, probably a little warmer on my black bike with the sun out. I know the manual says to measure valve clearances "at room temperature," but if this bike would fit inside my house, believe me I wouldn't be working on it outside! So I figured I'd just check the clearances anyways, note any glaring problems, and see what you guys had to say about it. Here's what I got:

Cyl#_____Exhaust_____Intake_____Spark plug condition

SPEC____.008-.010"___.006-.008" <--Listed tolerance in manual for "room temp"

1_______.0075"_______.0035"______Soot on the outside, white/tan stuff caked to top electrode
2_______.0085"________.0035"_____"Totally normal"
3_______.0085"________.0035"_____"Totally normal"
4_______.006"_________.00275"____"Totally normal"

Measurements are the average between the smallest feeler that COULDN'T fit in the gap and the largest feeler that COULD.

So, I thought these were kind of funny results. I expected the clearances to be larger than usual, not smaller, because I figured the valve end stays in place, so when the metal shrinks due to cold, the upper end of the valve retracts away from the cam.

What do you guys think - does the temperature really have a significant effect on the clearances? Has anyone else tried checking clearances in very cold weather?

If there's a consensus on that, then I can start worrying about what adjustments I need to make.

'Preciate it,

Marshall

[Crazcnuk]

The 20F is not going to make any real difference to your measurements.

the big change is from 60F-250F. Going from 20F-250F is not going to make a big difference.

You want to set as close to the 'large' setting as you can without going over, so take your measurements there and use the chart.

There is a Shim chart somewhere here you can use too.

[trbig]

It makes me wonder if maybe that was meant as a general statement so people wouldn't try to check them at operating temps. I agree that the cam/shim gap wouldn't change a measurable distance from 20 degrees to a normal 70 or whatever. As stated, shim them to the thickest tolerances you can get them since they get CLOSER as they wear.


Tod

[tinman905]

Okay guys, next question.

I have a 1980 XS1100 (G) Midnight Special.

Today I got the valve cover off and checked valve clearances. Thing is, I'm in Ann Arbor, MI and my "garage" is a patch of dirt on the side of the parking lot in my back yard (it's okay, my neighbors already thought I was a redneck). It was something like 20 degrees out today, probably a little warmer on my black bike with the sun out. I know the manual says to measure valve clearances "at room temperature," but if this bike would fit inside my house, believe me I wouldn't be working on it outside! So I figured I'd just check the clearances anyways, note any glaring problems, and see what you guys had to say about it. Here's what I got:

Cyl#_____Exhaust_____Intake_____Spark plug condition

SPEC____.008-.010"___.006-.008" <--Listed tolerance in manual for "room temp"

1_______.0075"_______.0035"______Soot on the outside, white/tan stuff caked to top electrode
2_______.0085"________.0035"_____"Totally normal"
3_______.0085"________.0035"_____"Totally normal"
4_______.006"_________.00275"____"Totally normal"

Measurements are the average between the smallest feeler that COULDN'T fit in the gap and the largest feeler that COULD.

So, I thought these were kind of funny results. I expected the clearances to be larger than usual, not smaller, because I figured the valve end stays in place, so when the metal shrinks due to cold, the upper end of the valve retracts away from the cam.

What do you guys think - does the temperature really have a significant effect on the clearances? Has anyone else tried checking clearances in very cold weather?

If there's a consensus on that, then I can start worrying about what adjustments I need to make.

'Preciate it,

Marshall

For the 80 xs1100G/xs110SG the intake clearence has been reduced to .004-.006 from.006-.008

[marshall]

For the 80 xs1100G/xs110SG the intake clearence has been reduced to .004-.006 from.006-.008

Wow, thanks for that. That actually makes a huge difference to me, as I need to swap a few less shims, and I'm willing to put up $8 a pop to do it locally rather than having to wait to go through the shim library. I need to be more careful and remember to check the 1980 supplement at the end of my Clymer!

[trbig]

$8?? Is that the only shop around? It doesn't have to be a Yamaha shop. A lot of them will trade straight across with you, but nobody should be getting more than $5 in my opinion.... unless it is the only shop around.


Tod