Forum bmwbike.com

At full throttle I lose power on my R50/2.

Here is my set up: Large air cleaner housing, 125 main jet, Hoske repro sport mufflers.

Power diminishes when I am at speed and then roll to full throttle.
Strangely when the bike is at rest, in neutral and I perform the same test, there is no
loss of power.

I thought It might be running thin, as the main jet controls the fuel mix at full throttle
so I upgraded to a 125 main jet with no noticable difference.

Then it was suggested that maybe at high revs the ignition jumps to ground in one
cylinder and that accounts for the loss of power...because then I'm only running on
one cylinder. I dispute this though, because power doesn't cut out when the bike is
at rest, in neutral and I do the same thing.

Any suggestions?

OK solved the full throttle problem. On full the bike now goes like it was
launched from a catapult. Well, it's and R50 so it's probably a SLOW catapult.
But now the midrange has a huge dead spot. Probably from about 50% to 80 %
throttle there is a power loss. All needles are in the recommended postions.

Suggestions?