Bonneville America Forums Forums Technical Forums General Tech Happy RPMs

I had a dream the other night, and I was also reading an old article about early Porsche 911s. It seems that if you bog the car down a little, say below 4000rpm, you carbon up the engine on those cars.

I was wondering if there was an ideal rpm for cruising around town with the BA to either prevent carbon buildup, if that still happens, or just for good practice for the engine health.

Thanks.Charles

Hi, if the carbs are jetted right, and the ignition is working right, then carbon deposits wouldn't really be a problem. Then again, I also check my plugs every month or so, to see how they're burning. If there was an RPM you would wanna cruise at it'd be the torque peak (4000 RPM), the peak is where the engine is turning out the best compromise of Power, Torque, and Fuel Economy, which means that's where the engine should be theoretically at it's most efficient performance level.

As they come from the factory, these bikes run so lean I doubt they can develop much carbon. Mine seems to pull very well at anything over 1800, but it seems to make a "happy sound" between 3000 and 6500, so I try to keep it in that range.

It is hard to "lug" this motor as the carbs are vacuum slides and work in harmony with manifold pressure to raise the slide, therefore, hard to bog-down the motor. Ain't no concern!