Logo
FULL SITE MENU

Carb issues???

7

75SeaShark

Member
So got the boat going. When first started, when I engage forward or reverse, it stutters out and dies. Rebuild the whole carb? Lean and rich settings?
 
Lets back up......
This is the 4cly with the neutral safety issue?

That control box had 2 versions. Actually more as the early (pre 68 I think) did not have neutral safety built into the shift switch. Only 3 wires.
Regardless, there was the I/O (& 100hp 68 outboard, same design lower unit) & the 1968 thru 72 50hp thru V4 excluding the 100 hp model above.

Basically the I/O goes into neutral with no power to either shift wire. The outboard version is no power in forward, power to 1 lead in neutral & power to both leads in reverse. Wrong switch will engage both gears in reverse & kill engine. I know you said it dies in fwd & rev. Just verifying.

Is engine truely running on all 4 cylinders? Did you check compression & spark? Have you tried to adjust the idle mixture screws (there is no high speed jet adjustment). Gently screw both idle mixture screws in until they stop & back each out 1 1/2 turn as a starting point. Since this thing has been sitting, probably will need to replace fuel filter & rebuild carb plus points/condenser. Set dwell & timing.
 
Droid said:
Lets back up......
This is the 4cly with the neutral safety issue?

That control box had 2 versions. Actually more as the early (pre 68 I think) did not have neutral safety built into the shift switch. Only 3 wires.
Regardless, there was the I/O (& 100hp 68 outboard, same design lower unit) & the 1968 thru 72 50hp thru V4 excluding the 100 hp model above.

Basically the I/O goes into neutral with no power to either shift wire. The outboard version is no power in forward, power to 1 lead in neutral & power to both leads in reverse. Wrong switch will engage both gears in reverse & kill engine. I know you said it dies in fwd & rev. Just verifying.

Is engine truely running on all 4 cylinders? Did you check compression & spark? Have you tried to adjust the idle mixture screws (there is no high speed jet adjustment). Gently screw both idle mixture screws in until they stop & back each out 1 1/2 turn as a starting point. Since this thing has been sitting, probably will need to replace fuel filter & rebuild carb plus points/condenser. Set dwell & timing.
Click to expand...
It’s a 75 140hp electric shift. 5 wire. The boat ran fine last year but he did say it would stall sometimes off idle into gear. If I use the warm up lever and just give it a bit of throttle and engage gear it does ok and gets up to speed nicely. Not gonna lie, in this day and age it has been awhile since I adjusted carbs. I was thinking just rebuild it but I will try the idle screws.
 
OK so you have the correct switch installed.

Just so you know that the 181 CID (3.0L) is a good strong engine. It idles a bit rougher than the 153 CID (2.5L). The 181 was never used in any GM car. It is an industrial engine.

BUT it has 1 weekness. Because of its large cylinder bore there is a spot between the cylinders that doesn't have a water jacket. Overheat it & you will warp the head & blow the gasket. That is why I said check the compression.

Shifting a Fossil Drive INTO gear at a fast idle can cause a broken shift spring. So do what you have to do to get a nice slow idle.
 
Back
Top