Topic: Nissan outboard Maintenance

[Bassaholic]

Hey everyone!

So im a pretty experienced car mechanic, I don't have any certifications by any means but i have been working on my personal vehicles since i was 16. I can do just about anything on a car. With that said last fall i tore apart my 3.5hp Nissan outboard to do some maintenance and fix an issue i was having. Still i have not been able to fix it.

Im not super experienced with Carburetors and i believe my issue lies within there. Did the typical spark plug replacement, ran some higher test gas thru it, made sure no plastic lines were cracked or leaking but for some reason i need to have the choke fully open on the motor in order for it to run, even when its warmed up. It also just likes to shut off every now and then and sometimes can be a total pain in the butt to start back up. Another issue is sometimes it just leaks fuel all over the place and im pretty sure that is because the carb is being flooded, i checked my tank and lines and there are no cracks or holes..

So im assuming its struggling to get Air into the carb properly, thus causing the gas to pile up because not all of it is being burned in a timely fashion...I have heard about the float getting stuck on carbs and  being a possible cause of this issue, but im curious if anyone could point me in the direction of what else to check out. The motor is definitely struggling and i know its capable of moving a bit faster then it does, or at least run much more efficiently...I could just buy a new carb for it but i may be buying my first bass boat within a few months and i would rather fix it so i can get a better resale value from it when the time comes.

Thanks for anyone who can help!

also its is not oil injected it takes a 50:1 gas/oil mix  I use Evinrude outboard oil

[Curt - NC]

@Bassaholic If you're having to run with the choke closed, it sounds more like a lack of fuel than a lack of air. Closing the choke creates a richer mix, due to allowing less air in.

With that said, is there any type of hindrance to the fuel supply to the carb?? Is there a fuel pump issue? Or it could possibly be carb related, as you've mentioned. How about the squeeze ball? Have you tried replacing that yet? Sometimes the ball can go bad and create a lack of fuel to the motor.

Maybe @bezerk can help with this too. He fixes outboards for a living.

Hope this helps. And let us know how you make out with it.

[Bassaholic]

Thanks for the info Curt. I do not believe there is any type of Fuel pump in the motor, looks like gravity does the job for the most part. Like i said i have inspected everything with the fuel lines into the carb and everything looks just fine, no cracks, leaks, etc so im thinking it has to do with the carb. could be that ball you are talking about, i think what you are referring to is what i was calling the "float" a bit white donut shaped thing in the bottom of the carb, i think that its sticking due to age or someting else.

Also @Curt - RI i have to have the choke fully Open for it to run, not closed

[Curt - NC]

Thanks for the info Curt. I do not believe there is any type of Fuel pump in the motor, looks like gravity does the job for the most part. Like i said i have inspected everything with the fuel lines into the carb and everything looks just fine, no cracks, leaks, etc so im thinking it has to do with the carb. could be that ball you are talking about, i think what you are referring to is what i was calling the "float" a bit white donut shaped thing in the bottom of the carb, i think that its sticking due to age or someting else.

Also @Curt - RI i have to have the choke fully Open for it to run, not closed

OK. A fully open choke and too much fuel would probably indicate a bad float. It may have a crack in it that's causing it not to float. Therefore it's still allowing fuel. Or maybe it's sticking in the down position. Either way, it's allowing too much fuel to enter the carb.

The ball I was referring to was actually the squeeze ball in the fuel line. Sometimes when they get old they can also cause problems, but it's usually more of a lack of fuel than an excess.

My guess is that you'll find that float being the culprit.

[Bassaholic]

Yea thats my guess, i will be tearing into the motor again next week when we get some warm temps =) thanks for the help @Curt - RI

I really hope we get warm weather soon! i love snowboarding but man i have all this new fishing gear and i need to use it!