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1994 force 90 hp fuel problem?

S

Sickie103

New member
I went to pump the bulb and it took quite some time to get firm. Usually it’s a couple pumps but now it takes a lot until it gets somewhat firm. I can hear fuel going somewhere. It starts every time but it starts up very slowly (low rpms the finally gets up) after sitting idle for a couple minutes it’ll slowly sputter and die. This has been an issue for years now but every time my neighbor just turns the idle up saying that it should fix the problem which is does temporarily. Now I can’t get it to stay running unless I put it in gear but even I’m gear if the rpms aren’t up enough it’ll slowly sputter and die. Could the fuel pump be weak/failing? Or could it be something else. I find it odd that it runs fine then does after a couple of minutes. Also whenever I try to go full throttle it seems as though the engine revs and the prop does not turn. If anyone could just point us in the right direction that would be awesome.
 
The ball should get hard and after starting go soft.
So if it gets somewhat hard???
#1 I'd say the fuel pump diaphragm needs replacing.
The fuel going past the diaphragm makes the motor run like crap.
#2 the fuel line connectors and maybe the ball could be bad.
The connectors have a rubber seal that goes bad.
The ball has a one way valve that can go bad too.

I'd start with the fuel pump and then replace he fuel lines and ball.
They're probably real old anyway.

The engine revving up and not going anywhere?
The hub in the prop could be bad and need replacing.
 
I will look into the fuel pump. I opened it up today and around all the carbs there was fuel/oil everywhere. It was not like this a couple weeks ago. My neighbor took the boat out the other day and when they got back he put the trim all the way up and left it like that. Could that somehow make everything drain out of the carbs? The gaskets look like they are in good condition and i cant figure out where it all came from. I tried pumping the ball to see if i could see if anything was leaking anywhere along with starting it and giving it a little gas...cant see a leak anywhere...
 
I replaced the fuel pump and it seems to have fixed the issue of not staying running at low rpm and the ball gets firm. It’s not running as good as I think it should be though. At low rpm it still sounds like it may die but never does. Would turning the idle up be the reason why it could be running poorly? Do the idle screws on all three carbs have to be in the same spot? Thank you for all your help
 
Those are NOT idle screws.
They are used to set the fuel/air mix at idle.
hey need to be adjusted in the water in gear.
You start at 1 1/8th turn out.
Then adjust from there.

The idle is adjusted from the towershaft.
It has a set screw close to the bottom.
It also needs to be done in the water, in gear.
800 in gear/1100-1200 in N
 
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