Do Carb. shims really add power?
Posted on the GWRRA BBS for Valkyrie by Jim E. on March 29, 1998 at 20:11:25:
I went on Sat. AM. Some sport bikes had already been through, but I didn't have to wait
at all...my bike is all stock except for .020" shims. I brought tools to remove them
for a second run but luckily the next bike after me was a bone-stock BumbleBee, the only
other Valk I saw. We both ran nearly identical, especially in HP. Torque curve looked a
bit flatter and started to build slightly earlier in the shimmed bike. The tuner suggested
leaving them in, but the difference wouldn't be worth sacrificing gas mileage to
me...haven't checked that yet though. Here's the results:
Dynojet Model 150 52.5 deg F Alt.100 ft.
SAE corrected horsepower (avg. of 3 runs): 93
SAE corrected torque (avg. of 3 runs): 93
The tuner was impressed with the torque and the wheelbase of the Valk...he had to adjust
the front wheel chock out to the "drag bike zone". The next bike after us was a
'98 heritage softail springer with (I think he said cams and carb work). That turned 50
hp.
- Jim E.