Honda Twins banner
1 - 4 of 4 Posts

·
Registered
Joined
·
1 Posts
Discussion Starter · #1 ·
I have an 85 cb450 nighthawk that runs to rich. I have gone through the carbs and cant find the problem. The jets are stock, floats are not adjustable and measure good, and I replaced the float valve needle. The pilot air mixture screw is set to the leanest setting and still the bike runs rich. It starts without choke even on cold mornings, gets poor gas mileage(25mpg), and the plugs look sooty. The air filter is new. Bike runs good and if not for the symptoms I mentioned you wouldn't think there was a problem from ridding it. Does anyone have any ideas on what i should look into next???
 

·
Sensei
Joined
·
27,179 Posts
Is the exhaust stock?
Is it possible you've swapped the primary and secondary main jets?
 

·
Registered
Joined
·
2 Posts
I had similar problems in with my '86 when I bought it. The previous owner had drilled the idle jet to compensate for vacuum leaks.

Another thing to check would be the brand of the jets. Different brands can have larger or smaller holes in the emulsion tubes. I tried an off brand set in my bike and it wouldn't even idle. After swapping for genuine Keihin jets, it ran great.
 
1 - 4 of 4 Posts
Top