I have a friend/neighbor that has two 99' XL1200 LTD witht the PV engine.

One runs fine and has the riva D plate and chip, SBT engine with the pump seal kit other that that it is stock. Very smooth from idle to WOT.

Now the one with the problems.
Same year it also has the rive D plate and chip, OEM engine with SBT PV clips and pump seal kit.

When you drive this one it will start and idle fine and go up to 1/4 throttle like normal but from 1/4 - 1/2 throttle it won't go any faster just a little louder and somewhat of a stutter then once you open up the throttle past 1/2 it will take off like it is shot out of a cannon it actuly runs a little faster then the other one 1-2MPH. Checking the spark plugs they all look the same with a tan color on each.

If you give it WOT from a stand still it will take off just like normal without and slipping or hesitation.

Anyway I switched the entire electrical box from one to the other thinking it may be a coil or plug cap but nothing changed.

I pulled the carbs and rebuilding them but they didn't look that dirty just the diaphrams and fuel pump valves were a little tired. Reeds look new and compression is even a @125 each cylinder. Since the carbs don't have high or low adjustments I can't belive that it would be a problem.

Anybody have any ideas on this type of problem or see it before.