r90s Running Rich

[schrader7032]

Stan -

It sure would be good to know what's under the tank...it's not too difficult to get the tank up; the fuel lines will the most hassle but they just unscrew at the petcocks. With the dual plugs and dual coils, there's a lot more combinations...my head hurts!

Your option 1) - you're just going to remove the ends at the plugs and switch sides, left to right. Assuming the plugs are OK, then if the problem reverses, then it's got to be the coils, right? If the problem does not reverse, that would seem to suggest the spark plugs.

Your option 2) - this sounds like a good test...I'd want to know how the coils are arranged under the tank for this one. It might give you some insight as to the kind of change you're making and how to interpret the results.

As for option 2, you'll have to plug wires that are not connected anywhere. To ensure there's no further damage to the coils, you should find a spark plug and put back into the open plug cap and ground the spark plug threads to the engine. This provides a path to ground for the spark if there is one there. Having a coil fire into the open air results in a lot of resistance and the coil doesn't like to see that. So, find a way to firmly keep the plug threads against the fins just in case.

Hopefully the light bulb will come on after a few more tests!

Kurt in S.A.

[VBMWMO]

Hello-
My wife and I just purchased an old Beemer with an r90s engine. We love it, but know next to nothing about the machine! In the first five minutes of ownership, I snapped the choke lever off. Argh. I bought a new (old) one from Re-Psycle in OH, and I put it in and it fit perfectly. The bike starts and idles w/o trouble, but I can't seem to reach highway speed, it sttruggles up hills, it stinks of gas and it's getting 18 mpg. Sounds to me like a fuel/air mixture problem, but I don't know what to do.
Help!
-Stan