1996 90HP Johnson will only run with primer on

fahlmanj

Recruit
Joined
Mar 3, 2012
Messages
1
I have a 1996 90HP Johnson model J90ELEDR . It was running rough so I tried to rebuild the carbs with new floats, needle valves, seats and gaskets. I cleaned all orifices using thin copper wire then sprayed carb cleaner reverse of the operating fuel flow direction, then sprayed the proper dirction and can see the carb cleaner blasting out all the holes (3 small holes in front of butteryfly valve and 1 bigger hole behind) . The low speed idle jets were set to 5 3/4 turns back from fully seated as per my manual.

When everything was re-assembled the motor no longer runs at all without primer (key pressed in). It will fire once or so without primer but will not run. It does run many seconds when key pressed in and stays running until key not pressed in or fuel line loses pressure and I have to squeeze primer bulb again.

I did do the sync and link after re-assembly and since is runs fine with primer, it definitly has spark and timing ok. It is just not getting any fuel. I have now removed and "re-cleaned" the carbs yet again but still no change. All four carb bowls are full of gas when I removed to I know for sure there is gas in there, it is just not getting to the engine.

Two things I have noticed: when I stop pressing the key in it dies immediately like the ignition was turned off. Ccould the kill switch on the key be doing this?

Also, three of the four side of the carbs where the plate and gasket go are slightly warped. I can see a little bit of the sealing ridge thus "may" be able to leak/suck air. It was very cold so the gaskets were somewhat hard too so may not have sealed well.

Any help on this would be greatly appreciated.
 

BonairII

Commander
Joined
Jun 7, 2011
Messages
2,727
Re: 1996 90HP Johnson will only run with primer on

Also, three of the four side of the carbs where the plate and gasket go are slightly warped. I can see a little bit of the sealing ridge thus "may" be able to leak/suck air.

You KNOW that they are warped? Or are assuming that they are because you can see some gasket sticking out on the edges?

If they are warped(not sure how that happens)....maybe you can double gasket the carbs.
 

boobie

Supreme Mariner
Joined
Nov 5, 2009
Messages
20,826
Re: 1996 90HP Johnson will only run with primer on

What kink of compression do you have and has it got good spark on all the cyl's ??
 

toddschubert

Chief Petty Officer
Joined
Sep 3, 2011
Messages
504
Re: 1996 90HP Johnson will only run with primer on

Could be sucking air in fuel line between bulb and tank if all carb issues. Check out
 

clanton

Rear Admiral
Joined
Jul 9, 2001
Messages
4,876
Re: 1996 90HP Johnson will only run with primer on

Did you use OEM kits? Did you put a washer on the float needle/seat when installed? Set float? If it runs only when primer is on, no fuel in carbuators. Fuel pump is working, because it is needed to work the primer.
 
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