'03 90hp Johnson--should I go from oil injection to gas? Is it ok to do so? HELP!

[jefdig]

I have a 2003 90hp Johnson and they say my fuel pump might be out, but not sure. Said it's cheaper and better to go from oil injection to mixing the oil with the gas and installing a different fuel pump as the one for it now costs $450 because it's oil injected. He states that if I change over and use mix, I would have less a chance of burning a piston down the line as it's typical in oil injection if they get plugged and no oil gets in the cylinder. Truth to this? Would you convert over? Is there anything else that could go wrong or I need to address if I change to mix? Do I simply pull the oil resivor and lines out then? Will this affect the motor in any other way? I know, alot of questions, but I don't have aclue and would like some advice! Thanks

 

[boobie]

Re: '03 90hp Johnson--should I go from oil injection to gas? Is it ok to do so? HELP!

When a mechanic says "might be out but not sure" I'd get awful nervous and look for a different mechanic.

 

[ondarvr]

Re: '03 90hp Johnson--should I go from oil injection to gas? Is it ok to do so? HELP!

What issues lead him to believe the oil injection wasn't working right?


To check and see if it's working, use pre-mix for a tank or so and leave the oil injection connected, mark the tank and see if the amount of fuel used matches the amount of oil it should use.

 

[jefdig]

Re: '03 90hp Johnson--should I go from oil injection to gas? Is it ok to do so? HELP!

I did check my oil use and it's using oil like it should be. Just telling the mechanic how it was running, he says best guess is the fuel pump is going out as it bogs out under load only at full and 3/4 throttle. If the oil is getting used properly, is it safe to say the fuel pump is working ok to? Could it be anything else? Thanks guys

 

[jefdig]

Re: '03 90hp Johnson--should I go from oil injection to gas? Is it ok to do so? HELP!

boat starts and idles great, just bogs out at full throttle for hole shot, and sometimes running 3/4 throttle. Any ideas what it could be?

 

[ondarvr]

Re: '03 90hp Johnson--should I go from oil injection to gas? Is it ok to do so? HELP!

If the fuel pump portion is bad, when it starts to bog down squeezing the primer bulb will increase the flow acting like a fuel pump and it should run fine (better). If the carb is plugged this may have no affect, but pushing the choke (primer button) will bypass plugged or restricted jets or float needles and it should run better.

Air leaks in the fuel line can cause this too.

 

[sterndrive tech]

Re: '03 90hp Johnson--should I go from oil injection to gas? Is it ok to do so? HELP!

i agree, i am a tecnician,, and i never use the words, might or might not, if i put a pump on and i have misdiagnosed , then i just ate a 400 dollar part.

 

[sterndrive tech]

Re: '03 90hp Johnson--should I go from oil injection to gas? Is it ok to do so? HELP!

this is a great trouble shooting practice ondarvr, also water in the fuel,as the boat s nose gets higher , the water level in the fuel tank rises at the back of the tank where the pickup is,

 

[sterndrive tech]

Re: '03 90hp Johnson--should I go from oil injection to gas? Is it ok to do so? HELP!

when the boat boggs, does it recover? or die down? a stuck timer base can also cause this as we are not advancing timing,, normmally happens from the stators epoxy, melting onto the plastic brng that lets the timer base turn

 

[jefdig]

Re: '03 90hp Johnson--should I go from oil injection to gas? Is it ok to do so? HELP!

It recovers. thanks guys for the all the input. I'm going to take another rider out with me to pump primer bulb while I try it and will check the choke.