Hello to all of you,
I am writing on behalf of my friend Dieter again. He has recently bought a C Comet to use for shorter trips rather than his shadow.
The bike had been restored 25 years ago and used since. It used a lot of oil and he bought a new 8:1 piston from the club and since fitting it ran the bike about 1600 miles.
The bike received a Mk II cam during restoration and the cam timing is spot on.
The ignition timing is 33 degrees, the bike has a 30 mm MKi concentric carb, inlet track is very smooth. First the bike had a Campbell spiral baffle silencer, now a straight through absorption type.
Gearing is standard for a comet.
Now to the problem, the bike does not perform!
Starting is great, idle as well. No hickups during acceleration.
He is of a 5 foot 5 size about 70 kg but the bike won't run faster than 60 miles on a straight line., slipstreaming maybe 70 miles with a very low slow pickup of speed.
We rechecked everything and ran out of ideas. The 60 MPH are reached with partial throttle but twisting the last 2 cm on the twist grip only changes the inlet sound of the engine but gives no more speed.
Rolling back the throttle also makes no difference, so the 200 main jet seems to be okay.
Do you have any idea how to make this Comet go?
Cheers Bernd
I am writing on behalf of my friend Dieter again. He has recently bought a C Comet to use for shorter trips rather than his shadow.
The bike had been restored 25 years ago and used since. It used a lot of oil and he bought a new 8:1 piston from the club and since fitting it ran the bike about 1600 miles.
The bike received a Mk II cam during restoration and the cam timing is spot on.
The ignition timing is 33 degrees, the bike has a 30 mm MKi concentric carb, inlet track is very smooth. First the bike had a Campbell spiral baffle silencer, now a straight through absorption type.
Gearing is standard for a comet.
Now to the problem, the bike does not perform!
Starting is great, idle as well. No hickups during acceleration.
He is of a 5 foot 5 size about 70 kg but the bike won't run faster than 60 miles on a straight line., slipstreaming maybe 70 miles with a very low slow pickup of speed.
We rechecked everything and ran out of ideas. The 60 MPH are reached with partial throttle but twisting the last 2 cm on the twist grip only changes the inlet sound of the engine but gives no more speed.
Rolling back the throttle also makes no difference, so the 200 main jet seems to be okay.
Do you have any idea how to make this Comet go?
Cheers Bernd