Have a 96 Johnson V4 90 hp 60 deg that does not run well. Recently purchased but know it was well taken care of. Sat unused for a few seasons. Carbs,fuel pump had recently been rebuilt before sitting. If this one had a VRO it was removed and replaced with the standard fuel pump.
When I first brought it out on the water it wouldn't get up to high speeds unless I hit the choke/primer solenoid. Idled rough with lots of smoke. Found water in 1 cylinder. Replaced rings and thermostat gasket. That fixed the water problem but still ran rough. Started going through the fuel system and found a few leaking hoses and a loose pump inlet, tighten'd those up and it seemed to run great on the muffs, was purring pretty well. Got it on the lake and it ran much better than before but still had to hit the primer to get it up to the top end. Assumed it was running lean so I brought it back home and pulled all the jets/ carbs. A few obstructions in the large jets but otherwise looked to be in great shape. Started it up and it was back to running really rough. Now pushing in the primer makes it stall
I have checked the fuel quality, was some water in the tank but motor operated the same on an auxiliary tank with fresh fuel. Removed and checked every hose from the tank to the carbs. Put inline fuel pressure gauge in several locations and got a constant 2 lbs,( LOW?) Would increase to about 15 when I squeezed the primer bulb but engine RPMs or rhythm didn't change then it would slowly go back to 2 lbs with no change in rpms or rhythm.
At times I have seen some fuel dripping from the carbs but all the floats seem to be working properly. Needles dont have any deformities or buildup. When I squeeze the primer bulb it gets hard and see some fuel dripping from connections at vapor separator, only zip ties holding them on.
I am currently going through the fuel delivery system 1 more time.
I have not adjusted the carbs (always been told not to until you rule out other issues. I tend to render more equipment useless by trying to adjust the carbs.)
Am I going down the wrong route with thinking its fuel delivery??
Primer solenoid test at 4.1 ohms and clicks when power applied
Compression on all 4 were around 110 if I recall.
Pulling plug wires changes idle on all 4 cylinders.
MODEL# J90ELEDR
SERIAL# G 04051791
When I first brought it out on the water it wouldn't get up to high speeds unless I hit the choke/primer solenoid. Idled rough with lots of smoke. Found water in 1 cylinder. Replaced rings and thermostat gasket. That fixed the water problem but still ran rough. Started going through the fuel system and found a few leaking hoses and a loose pump inlet, tighten'd those up and it seemed to run great on the muffs, was purring pretty well. Got it on the lake and it ran much better than before but still had to hit the primer to get it up to the top end. Assumed it was running lean so I brought it back home and pulled all the jets/ carbs. A few obstructions in the large jets but otherwise looked to be in great shape. Started it up and it was back to running really rough. Now pushing in the primer makes it stall
I have checked the fuel quality, was some water in the tank but motor operated the same on an auxiliary tank with fresh fuel. Removed and checked every hose from the tank to the carbs. Put inline fuel pressure gauge in several locations and got a constant 2 lbs,( LOW?) Would increase to about 15 when I squeezed the primer bulb but engine RPMs or rhythm didn't change then it would slowly go back to 2 lbs with no change in rpms or rhythm.
At times I have seen some fuel dripping from the carbs but all the floats seem to be working properly. Needles dont have any deformities or buildup. When I squeeze the primer bulb it gets hard and see some fuel dripping from connections at vapor separator, only zip ties holding them on.
I am currently going through the fuel delivery system 1 more time.
I have not adjusted the carbs (always been told not to until you rule out other issues. I tend to render more equipment useless by trying to adjust the carbs.)
Am I going down the wrong route with thinking its fuel delivery??
Primer solenoid test at 4.1 ohms and clicks when power applied
Compression on all 4 were around 110 if I recall.
Pulling plug wires changes idle on all 4 cylinders.
MODEL# J90ELEDR
SERIAL# G 04051791
Last edited:
