98 90 hp Johnson only running when choked

[al0311]

hey guys so I recently replaced my fuel pump because I had a problem with it dying under load.
so the other day I tested the fuel pump and realized it wasn’t pumping fuel at all. So I replaced it with a new one.
Go to run the boat today and at first it was running great no stalling no nothing Flying down the river, running nice. But then I started having a Problem. Problem I’m having now is I stopped and had a lot of trouble restarting the motor. It was bogging like before but this time when it would start to stumble I would push the choke key in and it would catch and run fine. I would have to keep priming it with the key switch.
It was not doing this before even if I did push the choke switch in, before It would just bog and die no matter what.

I got it home and took off the fuel lines to the carb and put them in a collection to see how it was flowing . cranked the motor over and the one side of fuel line to carbs was real weak almost as if nothing was coming out at all, the other side was a strong stream. So it’s almost as if it’s not getting fuel to the carbs at all right ? I’m not sure what I should do now I’m kinda stumped.
It can’t be the fuel pump right it’s brand new.
Its a 98 Johnson J90slecm is the serial number. Thanks guys.

 

[Faztbullet]

That motor has a OMS/VRO pump. Is that what was replaced and with OEM or aftermarket? A OMS/VRO only pumps when it clicks.

 

[Captain Jeff]

Could be a fuel restriction or clogged or closed fuel tank vent, does your primer bulb go flat? Another possibility it your pulse limiter is clogged with gunk or shot. The pulse limiter is the blue fitting on the bottom front of the engine that provides pulses from the crankcase to operate the diaphragm in the fuel pump. If you have both fuel lines off at the same time and crank the engine, it may be normal for more fuel to go to one side because of less resistance. If you plug the high flow side or leave it attached, do you get good flow on the weak side?

 

[al0311]

Captain Jeff That’s a good idea I will have to test that on Sunday when I have a day off to work on it more.

And fatzbullet i replaced it with a oms vro pump. Only time I can hear a click is when I push the key switch in if that is what you mean.

 

[Faztbullet]

You hear the primer(choke) click when you push key. The VRO will only pump after several, several engine revolutions when spring pressure is overcome in pump. It does not pump per engine revolution like a diaphragm type fuel pump.

 

[al0311]

Gotcha thanks for th reply. Even when it does turn over it stalls sometimes unless I keep pushing in the choke/primer.

 

[racerone]

model # is required as there are 2 different 90 hp models.----Compression test should be done.-----Having to use the primer indicates a fuel delivery issue.

 

[al0311]

Hi thanks for the reply Serial number is J90slecm is that the number your looking for ? I’m not sure the model number I’ll have to look when I get home