[piker]

Long story short. Have a 79 Kaw 650 SR. Sat for 20 years. Carbs were shot. Had someone get it running. Think they put some 80' carbs on it. The bike ran but backfires when backing off the throttle. After last ride smelled gas. Gas leaking from overflow. Wouldn' stop so I took off the gas tank. When I took off the tank gas, dripped from fuel tap. This is one of those taps that shut off when bike is turned off (vacumn). Would it cause the carbs to fill and overflow, or do I have carb problems?

 

[heineken]

You probably need a new vacuum petcock. I had the same problem on my old Ninja and it ended up ruining the seats in the carbs. Basically, the vacuum valve that keeps gas from flowing when the bike is turned off quit, so it's letting the pressure of the tank overload the carbs.

 

[QKENUF4U]

1. Gas leaking from overflow.

2. When I took off the tank gas, dripped from fuel tap. This is one of those taps that shut off when bike is turned off (vacumn). Would it cause the carbs to fill and overflow, or do I have carb problems?

1. did you replace the NEEDLE/SEAT or inspect them ? did you set the float height in the new carbs ? may be different for your year ?

2. since its leaking see if you can get a rebuild kit for it. sounds like the diaphram has taken a vacation and is not sealing correctly anymore.

if the petcock isnt working it can cause too much pressure on the needle and push past it causing your carbs to overflow into the engine. make sure yout oil is still clean/not overfilled with gas/oil now.
good luck