Total Motorcycle Community Forums

Hi everyone,

Just purchased a 1983 knighthawk 650. seems to be putting out quite abit of white smoke, not sure why. the guy says he put carb cleaner in the gas as it had been sitting awhile, don't know if he drained the tank or just topped it up.

Also, it seems to be hard to get moving from a stop on a hill.. need lots of rpms to get moving, don't know if this is normal. sometimes it bogs down a bit from a stop till you get moving, then it takes off well. Any ideas. We have to put new plugs in and do a compression test.

Also, will changing the gear oil in the shaft drive help with the up hill starts?

Thanks for any ideas,
Cheers,
Brian

Hi Brian, the Nighthawk 650 is a really cool bike!

If it was sitting for a while, the clutch may be gummed up a bit and causing the reluctance uphill, an oil change and some riding will help with that. Make very sure you have good clean oil before you ride any more.

It may also be a dirty carb, that's going to be more of a job but it can be done. No need to pull the carbs off yet, if it's running OK.

Very often when a bike is started up after a long period of sitting, it will smoke quite a bit at first.

I am hoping that the stuff the Previous Owner put in the gas is what is smoking. If this lasts more than a few rides, you may have to consider it's the motor.

Yeah what Coffee Brake said, although if after a few rides it still takes a bunch of revs to get going then I'm gonna say something is up with the pilot jet circuit.

As for the white smoke, no matter how much stuff he put in the carbs it shouldn't have lasted more than a couple of miles.

I'm gonna say if it's still putting out white smoke, especially on deceleration, then you're looking at a new head gasket.