Starting/Gas Hose Pressure Issues 90HP Johnson

I have a 2004 Johnson, J90GLSR with very low hours on it. It came on a Starcraft Fisherman, 1996, used in Ohio this Spring. It was originally set up for Lake Erie and surrounding lakes. Since purchasing it I have only used it at high elevation lakes. When I last used it at about 8700 feet, I had starting issues. The probelm was hard starting and when it did, idling for a moment or two and quitting. When I pumped up the pressure in the gas line, sometimes the pressure would build quickly and the bulb be hard, and sometimes it would stay soft. I stood a better chance of getting it to start and run when I could keep pressure. The other problem would be after I shut it off to troll with the kicker, the pressure in the line would drop and I would have to pump it up again when trying to restart it. If I didn't pump up the pressure in the gas line, it would not start. When it had pressure, I had a better chance of it firing and running. Once running it would run well at top end, not so well at idle. I turned each jet on the carburetor 1/4 turn to the right which seemed to help idle a little, but not the starting issue. I'm not sure what to think or how to solve the problem. Any help would be greatly appreciate. Thanks!!

Re: Starting/Gas Hose Pressure Issues 90HP Johnson

your motor was originally tuned to run at sea level, at 5,000 ft and above, there are changes that have to be done. different size jets, prop. it also sounds like you have a leak in the fuel line. or a carb float that is sticking.
8,700 ft, the motor has to be properly set up for that.

Re: Starting/Gas Hose Pressure Issues 90HP Johnson

Thanks for the prompt reply. When you say leak in the fuel line. Should I start searching from the gas tank backwards to the motor and then into the motor itself? Will follow up with some shops that are in the Salt Lake City area to see what they recommend for props and jets. Have a nice day.

Re: Starting/Gas Hose Pressure Issues 90HP Johnson

the leak could be any where there is a joint.

Re: Starting/Gas Hose Pressure Issues 90HP Johnson

I'd take a look at the check valves in the primer bulb. Once you pump the pressure up in the line it should basically remain (to a point). The check valves should hold (again, to a point) at any elevation, they don't know where they're at. Sometimes if the anti-siphon valve has been removed fron the tank outlet the line pressure doesn't hold like it should. Some aftermarket bulbs don't have check valves.

Re: Starting/Gas Hose Pressure Issues 90HP Johnson

agree