Question about 1993 Honda CB 750 Nighthawk
When starting bike with choke engaged, dark grey smoke comes out of pipes. With no choke, only smokes some times, mostly none. Clears up after a couple of minutes. Oil level fine. Hardly ever have to add.
Posted by Anonymous on
That sounds normal. Dark smoke is excess fuel due to the choke. Could be that the carbs need cleaned.
Posted on May 04, 2015
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Posted on Jan 02, 2017
White smoke indicates water in the combustion chamber. If the bike is still running okay I would keep an eye on the coolant level, make sure you're not losing any. Best guess is a blown headgasket. You can do a leakdown test or a compression test to check. If your headgasket is blown, two adjacent cylinders should show lower compression since pressure will be leaking from one to the other.
That's the kind of thing that probably won't run for long. Be sure and keep an eye on your oil level too, if you happen to be leaking coolant into the oil you can dilute the oil to the point it no longer lubricates very well.
Posted on Jan 05, 2009
SOURCE: 05 honda vtx 1800 runs rough
Your carb idle pins/needle valves are either fouled or worn/damaged. Or floats that control your equilibrium for gas distribution throughout the carb array are not working together with valves/pins. Has this bike set a spell, at least once for too long of an interval? I'd pull the whole darn carb setup and inspect/clean, then reinstall exactly to specs. Ask for the very best teardown/rebuild cleaner for carbs at the parts store! Betcha a little elbow grease and a perfect dismantle and clean, then rebuild is all you need! Been there----Did dat!
Posted on Jan 13, 2009
SOURCE: cbr 125 choke problem
It sounds like the choke line may not have been routed correctly when the new one was installed. Remove the gas tank and check to see that the line is not being stretched anywhere along the way AND that the gas tank when re-installed is not stretching the line. The line may have been kinked when installed. Look at the mechanical movement of the choke at the carb. Does it operate freely? Remove the air filter and look inside the center of the carb, (you may need to use a small mirror for this), does it look like the choke is opening and closing properly when the choke is moved on and off?
Posted on Mar 14, 2009
SOURCE: Engine problem
The bike has bad piston rings. The piston may need to be replaced and the cylinder may need to be honed or re-bored. If you continue to ride just don't let the oil get low.
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Posted on Jun 20, 2009
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