1985 Johnson 150GT

[Aces38]

I have a 150 GT. I have a couple problems and am not sure if they are related or not.
1.) When the motor is first started it seems to accelerate to full speed fine but after it has run awhile and you try to accelerate it seems to be like it is starving for gas or like the boat weighs a million pounds.
2.) When you are running at full throttle the boat only runs for a short time before it shuts down. If it is run at roughly half throttle it doesnt seem to have this problem. I have recently returned from a bass tourney and it seemed as though it was drinking the gas and not using much oil at all.

Could this be a VRO pump problem or am I going the wrong direction. I have recently replaced all electrical parts to rule that out. Fuel consumption was horrible I am hoping fixing this problem will cure that as well.

Please help.

 

[tashasdaddy]

Re: 1985 Johnson 150GT

well for the time being i would premix my fuel, as a safety freature. it will not hurt the motor. fill your oil tank, then keep track of oil vs fuel usage. is the motor running hot? have you check it with a infrared thermo. are you sure the vent is clear and open on the fuel tank? when were the carbs last cleaned and rebuilt. have you check compression hot and cold?

 

[ezeke]

Re: 1985 Johnson 150GT

There are not many original 1985 VRO pumps around as most have been upgraded to the VRO2 or OMS systems.

You might want to read the following thread, then see if it helps to explain your situation. http://continuouswave.com/whaler/reference/VRO.html

Remember that the VRO fuel pump feeds all of the carburetors at the same time, so problems related to the pump will generally not single out a specific cylinder, with the possible exception of the one providing the pulse.


In the meantime, what were the results of your compression test and your spark test?

 

[Aces38]

Re: 1985 Johnson 150GT

The compression is from 125 to 130 across all 6 cylinders. Would you recommend completely bypassing the VRO oil side and doing a premix or upgrading to a newer ststem.

 

[Aces38]

Re: 1985 Johnson 150GT

yes the overheating warning buzzer sounds. I am assuming this is related to not having enough lubrication causing it to run hotter

 

[ezeke]

Re: 1985 Johnson 150GT

You would be better off to upgrade the VRO system. It is simple enough to premix though. Just make sure that the premixed fuel has reached the engine before cutting off the oil side of the VRO.

If you decide to upgrade, be sure to use the pump with the number 5007*** or higher. I believe that 5007421 is correct, but check with the BRP dealer.

 

[tashasdaddy]

Re: 1985 Johnson 150GT

which alarm?

J/E Alarms

low oil alarm is a beep every 30 seconds. beep......................beep...................

no oil alarm is a beep every 1/2 second or so.beep,beep,beep

overheat alarm is a constant beep.beeeeeeeeeeeeeeeeeeeeeep

 

[Aces38]

Re: 1985 Johnson 150GT

Constant alarm. I have changed the thermostats as well to avoid one that may be stuck.

 

[Aces38]

Re: 1985 Johnson 150GT

Admiral -

Would this VRO pump being bad if it is cause the massive gas consumption?

 

[Aces38]

Re: 1985 Johnson 150GT

Would it be cheaper to bypass the VRO pump first and if this fixes the problem then just upgrade to a better system.

Also, do the make a retro fit for this motor to upgrade to fuel injection or is this just wishful thinking.

 

[ezeke]

Re: 1985 Johnson 150GT

Don't bypass the pump, just plug the oil side, disconnect the wiring for the alarms and oil tank, and run it - costs nothing. Just make sure that you premix the fuel to 50:1 gasoline to TC-W3 oil.

Also test the temp switch wires to be sure that they are working afterwards.

 

[tashasdaddy]

Re: 1985 Johnson 150GT

wishful thinking on injectors. you can disconnect the sender wires on the oil tank, and the sender wires on the vro pump, block the oil line, then you have to premix your fuel 50:1, disconnect fuel line at carbs, and pump until you get premixed fuel to the carbs. i think i would also recheck to make sure you have good spark on all cylinders, that can cause the increase fuel consumption.

 

[Aces38]

Re: 1985 Johnson 150GT

i will try this and let you all know what happens.

Thanks