Sbn 44 leaking

tnj4life

tnj4life

Location
Marshall, AR
Hey fellas. I think im the carb problem king on here. I recently put a sbn44 on my conversion ski, I started it for the first time today with the carb on. The carb leaks on the backside cover closest to the motor. Its a steady drip when running. Ive been through the carb a few times and can't find the problem. I slapped on my fx1 carb and it doesnt do it. Any ideas?
 
S

sflsurfrider

the needle and seat shouldnt make it leak on the outside cover.

which side of the carb is it on? pump or metering?

if its on the metering side, its because you have a small pinhole in the round diaphragm. if its on the pump side, it could be any of the gaskets or diaphragms.
 
tnj4life

tnj4life

Location
Marshall, AR
Metering, the ski is running retarded. If you rev it at all it revs up as high as the motor will go and the only way you can kill it is to prime it to death or choke it. Ill swap the black diaphram and see what happens.
 
tnj4life

tnj4life

Location
Marshall, AR
Yea I changed the diaphram, fixed the leak. Just got back from the lake. I debated whether to take it or not with it revving crazy. I knew my carb was out of tune and didnt know whether my jetting was close or not. Since this is the only ski I have running at the time I thought I would take it to see what it does in the water. The water was FREEZING. Put the trailer and ski in the water with the straps on it and adjusted my highs and lows. With the ski in the water it didnt rev up like before. After tuning it I managed to get it to run well, better than the 38mm keihin that was previously on it. I need to go richer on my pilot as my screw is turned out a few turns. The ski pulls great from low to top, and idles well, never tries to runaway like out of water. But on land with the ski running if you blip the throttle a few times it revs so high that you have to choke the motor to kill it. I still have some tuning to do, but doesnt it sound like I still have an air leak?
 
tnj4life

tnj4life

Location
Marshall, AR
Well, I do need a lanyard, but in this situation the only way to kill it when it does that is to prime the crap out of it. The kill swich wont kill it, niether pulling the plug wires, ive tried both. It kinda makes me nervous riding it. Ive gotta fix this, my wife usually rides this ski and i'll never here the end of it!
 
SUPERTUNE

SUPERTUNE

Race Gas Rules
Location
Clearwater Fl.
Do a pressure check 1st.
Make 1/4 aluminum plates to go on the exhaust and intake with plumbers rubber (from home depot) to seal with grease and pressurize to 8-9 lbs through the pulse fitting.
 
Last edited:
Matt_E

Matt_E

steals hub caps from cars
Site Supporter
Location
at peace
It won't rev to the moon in the water because the motor has a load on it in the water.
A runaway motor happens without load.

That said, don't ride with an airleak.
 
tnj4life

tnj4life

Location
Marshall, AR
Yeah, time for a another pressure test. I figure its at my intake manifold. I did ride it though, I know, im dumb. I've had a bad case of cabin fever. My body went numb though, as I was in trunks and a life jacket in 40 degree water. It was kinda funny though when I would fall the cold water would literally take my breath away for a few seconds. My cousin is dumber, he was on a js400 with no turf.
 
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