[AlphaAndOmega]

Just as the title states, I'm wondering what the process is to set the cam timing on a XR80 motor. Its out of a '84 I believe, although I don't think that matters as it looks pretty similar to my XR75 (which I've never had to set the timing on).



Pictures would be great, but I'm guessing they are a bit harder to come by on this vintage stuff. A description of where the timing marks are would also work.

 

[Pat Farsole]

Line the "T" mark on the flywheel up with the index mark on the LHS crank case ... then attach the cam chain with the "O" mark on the cam sprocket at the top pointing to 12 O'clock ... simple ...



Rocker clearances should be set at .002" (2 thou inlet and exhaust) while both timing marks are held in those positions ...

 

[firepower354]

I prefer a little more oil clearance, like .003-.004, but either is fine.

 

[AHRMA361]

I prefer a little more oil clearance, like .003-.004, but either is fine.

What he said ^^



I always run mine at .004....... .002 is a little tight in my experience...and .004 isn't the least bit noisy....

 

[AlphaAndOmega]

Thanks for the advice guys. I'll have to take a closer look and find the index mark on the case. Seems pretty straightforward. Hopefully I can hear this monster run in the near future.

 

[Pat Farsole]

A bit of extra clearance won't hurt but I've NEVER had a problem with .002" clearance with the stock cam in 35 years in Australian summer heat ... Honda service manuals state .002" ...



XR 75 Tune Up specs

 

[Dracut50]

where did you guys get your feeler gauges for the valves? i cant find any that small any where

 

[goinsriding]

Feeler Gauge - 32 Piece, SAE/Metric

 

[Dracut50]

So a .002 is really a 0.0020??

 

[dirtbkr188]

yep...

 

[Dracut50]

My smallest feeler gauge reads .006 and .152mm

 

[dirtbkr188]

You'll need to get the thinner set of gauges to be able to set the valves at .002" and .003" or .004"

 

[GSjimmy]

Harbor Freight - $4.00