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The Carb specs for XR80

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I want to verify a baseline for my 1980 XL to XR80 convert.

Can one of you with tuning knowledge throw me bone.

What carb should be on this machine for a start A Keihin PC10,20 etc.

My main jet is at sea level a 105 per BBR and Powroll, pilot is a 35 per same.

I have not looked at what needle, slide, or emulsion tube is in it (the XL parts are different). The carb was replaced a while back. The piston is a new, one over wiseco, the pipe is a Powroll, the cam is a new old stock 1980 XR. needle position? Type needle? mix screw setting? What should be stamped on the carb PC???

in addition any final drive suggestions? thanks Rob

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This is from the Clymer XL/XR 75-100 1975-1990 Manual.

Not the best, but better than nothing.

1980-1984 XL80S

Carb PF65B

Main 72

Slow N/A

Pilot 2-3/4 turns out

Needle Fixed

Float 16.6mm (0.65 in)

Idle speed 1500 +/- 100



Main 92

Slow 35

Pilot 1-1/2 turns out

Needle 4th groove (On my XR80 3rd, middle, worked 100% better!)

Float 20.0 mm (0.787 in)

Idle speed 1500 +/- 100

I put a new carb on my 1979 XR80 jetted to these specs.

It ran like crap mid throttle. Dropped the needle to the 3rd, mid setting, and it ran great. I could test a larger main jet, but this bike is for my wife and son to learn on. Maximum throttle is not a concern. I can start it with my arm. Easy starting is a concern.

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