Valve adjustment question

JimMoore · Dec 10, 2006

I have been spending a lot of time at high rpm (6500+) on my oilheads. The valves have been changing (tightening up) to a much greater degree than they did when I rode at lower rpm. You might want to check them more frequently if you ride at high rpm frequently.

PGlaves · Dec 10, 2006

JimMoore said:
I have been spending a lot of time at high rpm (6500+) on my oilheads. The valves have been changing (tightening up) to a much greater degree than they did when I rode at lower rpm. You might want to check them more frequently if you ride at high rpm frequently.

That is interesting. Are there any theories or observations as to whether the going out of adjustment is due to metal wearing away, seat recession, valve head deformation, or adjusters rattling loose? Something has to be making the clearances change. If they are closing it sounds like either the seats are wearing or the valve heads are deforming. Stem stretch could be a possibility too. None of these are good things.

glwestcott · Dec 10, 2006

JimMoore said:
I have been spending a lot of time at high rpm (6500+) on my oilheads. The valves have been changing (tightening up) to a much greater degree than they did when I rode at lower rpm. You might want to check them more frequently if you ride at high rpm frequently.

Why would you ride at such high rpm? That's outside the power curve and simply going to cause more wear than necessary. Lugging is bad, but so is over-revving. :hide

dpmonk · Dec 11, 2006

finding tdc and adjusting valves

I don't remove the timing hole cover. It is a pain in the A** to get back in.
Instead I roll the engine with the rear wheel in 6 gear and watch the valves move. When they both open and close I insert a wooden dowel rod through
the spark plug hole and gently roll the piston to tdc with rear wheel.

Last service at 36k I didn't have to change the clearances. Just used .008 on intake and .014 on exhaust to be sure I wasn't too loose after checking with .006 and .012. But I don't ride very hard.

kbasa · Dec 11, 2006

glwestcott said:
Why would you ride at such high rpm? That's outside the power curve and simply going to cause more wear than necessary. Lugging is bad, but so is over-revving.

On our 94RS, peak torque is at 4500rpm and the hp peak is at redline.

I spend just about all my time between those two points. :dunno

drrider · Dec 24, 2006

the directions taken from the advrider forum was great, but leaves me with one question. :dunno

can someone explain how leaving the timing plug out could effect the way the bike runs? :lurk

mine's been gone for a long time

j-budimlya · Dec 24, 2006

drrider said:
the directions taken from the advrider forum was great, but leaves me with one question. can someone explain how leaving the timing plug out could effect the way the bike runs? mine's been gone for a long time

Keeping rain, oil, and dirt out of the flywheel/clutch is probably a good thing...however, it will run for some considerable time without the plug...

Valve adjustment question

JimMoore

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PGlaves

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glwestcott

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dpmonk

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kbasa

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drrider

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j-budimlya

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