1999 90hp johnson problem!!!!

[TEXAS ROD WORKS]

I bought a new boat that has a 1999 90hp on it , motor runs great ,when you run it wide open it will go bought 500yds and then act fuel starved. the guy that had it before me put a 5psi priming pump in line between the fuel filter and the tank. I have changed the vro pump and also bipassed the filter and 5psi pump and went from the tank to the motor ,still does it. the boat idles well . what do i check now? also if i turn the 5 psi pump on it will run and never act fuel starved.

 

[tashasdaddy]

Re: 1999 90hp johnson problem!!!!

will it pick up if you have someone squeeze the fuel line bulb? is the arrow on fuel bulb pointing toward the motor. could be dirty high speed jets, or sucking air in a fuel line joint.

 

[TEXAS ROD WORKS]

Re: 1999 90hp johnson problem!!!!

I tried looking for kinks in the line and also leaks everything looks good what next ? guessing check the high speed jets ? if i pump the bulb when it starts to act fuel starved it picks right back up , what else could it be?

 

[trendsetter240]

Re: 1999 90hp johnson problem!!!!

Sounds to me like your fuel pump is not working. Which is probably why the previous owner installed that 5psi priming pump.

When you bypass the VRO, where do you connect the fuel line that comes from your gas tank? If it is connected directly to the fuel line T connection that runs to your carbs, you have bypassed your fuel pump along with the VRO.

 

[Faztbullet]

Re: 1999 90hp johnson problem!!!!

Check the fitting on fuel tank, if its made of aluminum its a anti-siphon valve..replace it with a brass one. It sounds like a fuel restriction and the pump is adding extra fuel. Has the boat set before purchase? Check the fuel pressure from VRO pump, use a inline pressure guage. Start and set idle @ 850 rpms and check pressure, it should not fall below 3psi..if it does its a faulty VRO or the pulse fitting is obstructed..

 

[TEXAS ROD WORKS]

Re: 1999 90hp johnson problem!!!!

still can't figure this one out !!!! I have checked all of the hoses , the tank, all fittings ,I even tried to run it on a portable tank and it still does the same thing . I even changed the pulse limiter fitting . guess the next thing would be to check float height to see if they are correct. surely this is not a block problem, the compression is near factory. any other ideas??????

 

[TEXAS ROD WORKS]

Re: 1999 90hp johnson problem!!!!

Sounds to me like your fuel pump is not working. Which is probably why the previous owner installed that 5psi priming pump.

When you bypass the VRO, where do you connect the fuel line that comes from your gas tank? If it is connected directly to the fuel line T connection that runs to your carbs, you have bypassed your fuel pump along with the VRO.

the fuel line is still running to the housing that the vro fits into, on the end of the fuel line there is a conical filter it scews into the the the same mount that the vro plugs into,.

 

[noelm]

Re: 1999 90hp johnson problem!!!!

you seem to have it in your mind you have a carby trouble, but I think you don't, you have a fuel pump problem, by pumping the primer bulb, you in fact sort of taking the fuel pump out of play, the carbies are still the same, replace or repair your fuel pump, do not get side tracked by over complicating the whole thing.

 

[TEXAS ROD WORKS]

Re: 1999 90hp johnson problem!!!!

I was under the impression tha the vro was the fuel pump, one side fuel one side oil . they make 2 diff vro pumps. one for oil injection one for pre mix . I replaced the pump with the pre mix syle pump, brand new.

 

[TEXAS ROD WORKS]

Re: 1999 90hp johnson problem!!!!

can you remove the vro on this motor and add a regular fuel pump?

 

[TEXAS ROD WORKS]

Re: 1999 90hp johnson problem!!!!

ttt

 

[lpolk22]

I have the same problem. Replaced fuel line and VRO. Dose not appear to be sucking air. Still have to pump primer ball to keep motor running. I did replace VRO with aftermarket part. Could that be the problem?

 

[jbcurt00]

I have the same problem. Replaced fuel line and VRO. Dose not appear to be sucking air. Still have to pump primer ball to keep motor running. I did replace VRO with aftermarket part. Could that be the problem?

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