1981 RM100 Carb Settings

[cchalmers]

I recently acquired a 1981 RM100 as a throw in to the purchase of a 1997 XR600R. The RM will fire up fine on choke and warm up. When throttling the engine responds well for about 10 - 20 seconds, but then lowers the RPMs regardless of throttle position and then dies.

Does anyone have the Clymer manual available to send me the OEM carburetor specifications and settings? I would like to set it up to the original tuning and see how it responds. Unless someone else has any other ideas.

Thanks for your help,
Chad

 

[zoommx]

Sounds like a fuel supply problem to me. Slow filling of the bowl due to a restriction somewhere. I had the same problem with an old Yamaha and found some crud sitting in the carburator fuel passage above the needle valve. Not only would it die after the bowl went low, it would overflow when not running because the crud would keep the needle from seating.

Good luck, Roger

 

[cchalmers]

Thanks Roger.

I wasn't considering that but it does sound reasonable. I guess I could check that and clamp off the fuel line as the bike dies then drain the bowl. Does that make sense?

I thought that maybe I needed to adjust the jet needle to run a little richer - which I am about to try.

 

[cchalmers]

Well I tried adjusting the jet needle on slot richer and thoroughly examined the fuel in let line. The inlet line is clear, I gravity ran fuel through it and it came right out. And the jet needle adjustment produced the same results - motor bogs out after throttling past 1/4 turn.

Any other Ideas out there??

 

[whenfoxforks-ruled]

You have to look at your plug. Take the bowl off and confirm that the float valve is working seemingly okay. That is a yealy replacment item by the way. What kind of sparkplug is in it? Is the timing set properly? How is the silencer packing, filter and reeds? That manual would cover all these areas.

 

[cchalmers]

Got it working. Thanks to those that helped.