Logo
FULL SITE MENU

1984 90HP Johnson stops running

S

stuke

New member
My 84 90 HP VRO Johnson stop running when cruising. I can be going along just fine and then the engine acts like it's out of fuel and stops. The primer bulb is hard as a rock. If I wait a couple of minutes the engine starts and I go through the cycle again. Time varies between shut downs, but is usually about 2 to 3 minutes. I checked the filter and gas flows freely, tried a new hose and changed gas tanks with same results. I did notice the gas level in the filter goes down to the point of near nothin when fast idling the engine. No alarms go off when this is happening. Oil tank is full. The boat and motor were in storage a couple of years prior to this outing, fuel stabilized and engine fogged. Engine starts and runs good otherwise, maybe a little rough on idle. I talked to a Marine dealer in the area I was fishing and he seemed to think it was the VRO pump. thanks in advance for any help.
 
Does it stop instantly like you turned the key to off, or does it sputter and slow down before it dies?-------Has the waterpump been inspected , impeller replaced ?-------Have you confirmed that the VRO pump is indeed working properly ?
 
Lower unit has been rebuilt and pressure tested a couple of years ago and is working. It does sputter and lose RPM before it dies, I suspect from no gas. Don't know how to check if VRO is working but have been told alarms would be goingoff it it wasn't.
 
There was no alarm on the 84 VRO units!-----It may have a newer one installed with an alarm circuit.-Any wires on the VRO pump ?--------Use the manual fuel pump on the hose when motor falters and see if that improves the situation.---------What are the results of a compression teston this motor ?---------------If there is mechanical damage inside the motor there may be an issue with crankcase compression ( different from cylinder compression ) and that is what operates the fuel pump.
 
Found a brittle and broken line from the crankcase that drives the pump. Will replace and see if this solves the problem. Doesn't explain the rock hard manual bulb unless the oil pump was causing it. Engine must have been running on fuel manually pumped into carbs. Thanks for all the helop, will post again if problem continues.
 
My mistake, after taking the starter off to get at things, it turns out to be the oil line hose. Also, there are no wires running to the fuel/oil pump. Can this oil line be replaced with standard fuel line hose?
 
If there are no wires from the VRO pump then it is an original 84 and not to be trusted.----So if the oil hose was bad it may have been sucking air instead of oil !----Perhaps you should now do a compression test.-----------Sorry that I can't stand beside your motor to do the simple checking.-----Just replace it with standard fuel hose and hope for the best.------You might want to mix at 50:1 untill you confirm that the VRO is indeed working properly !!
 
Already replaced it with fuel hose. Also found the inline filter in the old hose. Cleaned it and put it in the new hose. Also planned on running mixed fuel as you said. Any info on what the compression should be and how to perform the check would be helpful. Do you do it like an auto and just turn the engine over? Trying to find the proper way to prime the oil line. You are correct about it being original as is everythig but the spark plugs.
 
Back
Top