Supplemental service manual

[Crazcnuk]

Hi there, I can't find my supp manual, but I seem to remember there was a change in it to the valve clearance specs for the 80 models?

I have the valve cover off the special, to check the valves, and just want to double check what they should be set to.

I also have to remember where I put my extra valve shims... bleh

[XSPastor]

1980 valve clearances

intake is .004 - .006 (.16 - .20mm)
exhaust is .008 - .010 (.21 - .25mm)

[Crazcnuk]

Thanks, is that the regular settings or the revised ones?

[tinman905]

intake is .004 - .006 (.16 - .20mm)
exhaust is .008 - .010 (.21 - .25mm)

The intake was changed for 1980 to .004-.006 which you have is correct but it should read ( 0.11-0.15mm ) instead of "(.16-.20mm)" according to the the Yamaha supplementary and Chylmer's manual.

[XSPastor]

Yup!

The intake was changed for 1980 to .004-.006 which you have is correct but it should read ( 0.11-0.15mm ) instead of "(.16-.20mm)" according to the the Yamaha supplementary and Chylmer's manual.

You're right - I copied it incorrectly! Oops. Thanks for the correction!

[randy]

Checking my manuals and my supp manual for the G and SG models shows a change in cams for the 80 models. The G and SG intake cam has .03mm LESS lift than the E and F models. Is that the reason behind the clearance change? Is it OK to use the tighter clearances on the older cams? Anyone done that?

[DGXSER]

Randy,

The Clymers manual suggest that you not use the tighter clearances on the older models. No explanation why though.

[tinman905]

Checking my manuals and my supp manual for the G and SG models shows a change in cams for the 80 models. The G and SG intake cam has .03mm LESS lift than the E and F models. Is that the reason behind the clearance change? Is it OK to use the tighter clearances on the older cams? Anyone done that?

I the supplementary manual it just states " to reduce engine noise"