Valve check and adjust

[Kevcules]

Hello again

I'm checking the valve clearances on my 87 Yamaha FZ 600 and am getting confused with what I see in the manual and just want to be sure...

1. Why does the manual give an example of a valve being loose , then re-shimming to get within a tighter spec, isn't it the opposite? These valves get tight don't they??

2. Why does the manual say I have to line up the "T" with the "upper" pick up coil when I only have a lower one? I lined up the "t" with it and it seemed to make the cam lobes be properly positioned.

3. Are these the actual valve specs for this bike, the tolerance seems small?
Intake .11 mm to .15 mm ( .004" to .0059" )
Exaust .16 mm to .20 mm (.006" to .0079" )

I'm going to have to get a better set of gauges because almost all the valves are set at ... .127 mm will not fit except for one exaust valve where .178 won't fit in .

I tried uploading some pics but I guess they didn't work...

[TFOGGuys]

Hello again

I'm checking the valve clearances on my 87 Yamaha FZ 600 and am getting confused with what I see in the manual and just want to be sure...

1. Why does the manual give an example of a valve being loose , then re-shimming to get within a tighter spec, isn't it the opposite? These valves get tight don't they??

2. Why does the manual say I have to line up the "T" with the "upper" pick up coil when I only have a lower one? I lined up the "t" with it and it seemed to make the cam lobes be properly positioned.

3. Are these the actual valve specs for this bike, the tolerance seems small?
Intake .11 mm to .15 mm ( .004" to .0059" )
Exaust .16 mm to .20 mm (.006" to .0079" )

I'm going to have to get a better set of gauges because almost all the valves are set at ... .127 mm will not fit except for one exaust valve where .178 won't fit in .

You can have valves tight, loose, or within spec after a long period of time. If the clearance is smaller than the low spec, fit a thinner shim, if it is larger than the high spec, fit a thicker shim. If the valve is in spec, leave it alone. Exact TDC is not super critical, when you check the clearance on a cylinder, the cam lobes will face mostly away from each other, about the same angle away from the spark plug. It's best to get a metric feeler guage, as the original specs are metric. The specs you quote seem to be about average, most water cooled bikes run a bit tighter, except for Kawasakis. Clearance is dependent on a number of factors, including cylinder head design, cam lobe design, valve train type, and materials.

[Kevcules]

Thanks for the reply TFOGGuys

I actually also have a Kawisaki KLR 650 and just did the valves last year and that's exactly where I compared the tolerances to. They are higher for the Kawi.
Does everyone use the Yamaha special tools to change the shims? There is the OEM bolt on type tool and also the Universal tool. You could also remove the camshaft bearing caps but is this something one should do?

Kevin

[TFOGGuys]

It's faster and easier to use the tool, particularly when you are only adjusting a few valves; you really have no chance of mistiming the cams and causing real engine damage.

[Kevcules]

Sounds good , now I'll hope to borrow one and if not to pricey , I'll purchase one.

Thanks

Kevin