We’d describe this custom B-King as a flamboyant, somewhat less than practical motorcycle…(!) It may have had something to do with the Transformers in its life. The owner (who’d been royally messed around by all and sundry) brought it to us with a Power Commander to set up; we explained that really wasn’t the way to go (more of which shortly) and an ECU remap would be a better bet all round.
Now it had onboard a custom-made – and very short – exhaust pipe, and the lambda was also no longer in play. As ever we were keen to do a good job, and through the ECU could switch off all the excess emissions interference.
He was up for it, so we stripped out the PC and got on with the remap. In truth it wasn’t about power gains, more like making it run as best it could. The pipe was so unrestricted it had become restrictive, with zero backpressure and that’s a situation a PC simply can’t adjust for.
To help it work we got into the Manifold Air Pressure (MAP) tables and started adjustments from there. It was so lean off idle, in the closed loop area that a PC ‘overall’ trim simply wouldn’t register the issue. There was a lot of popping and banging going on too, which more fuel sorted as well. Strangely enough it needed less fuel on full throttle… lack of back pressure again.
Power? Same as a stocker, which we’re not proud of – but now at least it runs properly!
It’s certainly brave, but not overly practical…
And that, as they say is a rear tyre. Side stand optional.
The custom exhaust was a large part of the running issues.
