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View Full Version : Now a carb issue with my 91 Prostar...


SWGA Boater
06-22-2013, 06:54 PM
Moving on from an oil leak to a carb problem. :mad: Boat seemed to run fine last weekend except for an oil leak (see previous thread). I think I have solved the oil leak. Ran the engine off/on for about 20 minutes on the hose at 1500-2500 rpms. No overheating, no oil leak to speak of.

Problem is engine stumbles and will not idle as carb is loading up. Back secondaries are continually dribbling gas. My dad rebuilt the carb a few weeks ago and it seems to have ran fine until today.

Any idea on where to start or what to look for? I removed to large screw left side of front bowl and gas barely dribbled out. I was thinking the float but not sure. Also, sprayed some carb cleaner around the carb and no vacuum leaks to speak of.

Thanks,

Ansley

j.mccreight@hotmail.com
06-22-2013, 06:56 PM
Moving on from an oil leak to a carb problem. :mad: Boat seemed to run fine last weekend except for an oil leak (see previous thread). I think I have solved the oil leak. Ran the engine off/on for about 20 minutes on the hose at 1500-2500 rpms. No overheating, no oil leak to speak of.

Problem is engine stumbles and will not idle as carb is loading up. Back secondaries are continually dribbling gas. My dad rebuilt the carb a few weeks ago and it seems to have ran fine until today.

Any idea on where to start or what to look for? I removed to large screw left side of front bowl and gas barely dribbled out. I was thinking the float but not sure. Also, sprayed some carb cleaner around the carb and no vacuum leaks to speak of.

Thanks,

Ansley


probably a bit of trash under the needle seat.

SWGA Boater
06-22-2013, 10:50 PM
Easy to do? Will I have to take the front bowl off? I'll pull up the PCM service manual. I think it had some carb info also.

j.mccreight@hotmail.com
06-23-2013, 12:07 AM
Easy to do? Will I have to take the front bowl off? I'll pull up the PCM service manual. I think it had some carb info also.

sometimes a moderate wack with a rubber mallet can free lodged debris from the needle/ seat area otherwise front and rear bowls are easy enough to remove and check and clean, you don't need to remove the carburetor from the intake manifold.

thatsmrmastercraft
06-23-2013, 12:20 AM
sometimes a moderate wack with a rubber mallet can free lodged debris from the needle/ seat area otherwise front and rear bowls are easy enough to remove and check and clean, you don't need to remove the carburetor from the intake manifold.

Agreed.....it sounds like a little debris. If the mallet trick doesn't do it, Popping that rear bowl off will to clean things out is a breeze. If you don't have blue reusable gaskets you will need to pick up a new one. The tan fiber gaskets are virtually never good for a second time. Use a little caution with the o-ring on the fuel transfer tube. A little saliva will assist in reassembly. Had to do this operation at the dock on the first day of vacation a couple years ago.

If fuel filters weren't changed when the carb was rebuilt, I would change them. Could also have some debris in the fuel tank.

SWGA Boater
06-23-2013, 12:30 AM
Thanks for the suggestions. I'll try them tomorrow. I have been watching a few YouTube videos on needle and seat adjustment. Maybe the malet trick will unstick it. Filters were changed at the time of the rebuild.

I also drained the tank and cleaned it, replaced all the fuel lines and installed a fuel/water separator (between tank and fuel pump) and filter after the fuel pump at the time of the carb rebuild. Should not be any trash getting to the carb, but you never know...

thatsmrmastercraft
06-23-2013, 12:32 AM
Sounds like a random piece of junk for your amusement. You should double-check the float adjustment while you have the secondary bowl off.

SWGA Boater
06-23-2013, 03:14 PM
After a few medium taps on the secondary fuel bowl something freed up and the boat ran fine on the hose this morning (no oil leak to speak of either). I was hoping to try it out this afternoon but the rain just rolled in....

Thanks Jim and Peter for the suggestions!

thatsmrmastercraft
06-23-2013, 04:05 PM
It is also possible that the float got hung up and was the cause of this, but Jim's thought on debris is the most likely issue. Keep the mallet in the boat for a while.:rolleyes: