90 hp v4 johnson

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thomasonbunch

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I have 90 hp v4 johnson fuel side went out so we replaced the vro with a new pump so we now have to mix the fuel put it on now it starts up the runs about 2 or 5 seconds and then dies i pulled the carbs off and they were clean and not pluged put it back together and still does the same thing and even checked the spark on the plugs .I have one question the wires that went to the vro we just disconect them from the vro should they have to be connected ?
 
AEROCOOK

AEROCOOK

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Re: 90 hp v4 johnson

Step 1, please provide the model number. What fuel pump did you put on it? After it starts and just before it dies, try pushing the key back in for a second or so to give the motor another prime.
 
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James R

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Re: 90 hp v4 johnson

Leave the plug disconnected. Try applying hand pressure to the primer bulb to keep the motor running. If it does run you have a fuel pump problem.
 
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boobie

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Re: 90 hp v4 johnson

Have you got this "new fuel pump" plumbed correctly ?? Did it ever run after you put it on?? Or is it another vro ??
 
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thomasonbunch

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Re:1984 90 hp v4 johnson

Re:1984 90 hp v4 johnson

the pump we put on is not a vro we put regular pump and the number is 0438556 we got it from the dealer and he said this pump would work for the motor that replaces the vro pump is 1984 90 hp v4 model # is J90MLCRD and so we have to mix the fuel
 
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thomasonbunch

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Re: 90 hp v4 johnson

AEROCOOK said:
Step 1, please provide the model number. What fuel pump did you put on it? After it starts and just before it dies, try pushing the key back in for a second or so to give the motor another prime.
Click to expand...

the model number is j90mlcrd the fuel pump we put on is to replace the vro pump the # 0438556 and we got the fuel pump from the dealer and the motor is a 1984 90 hp v4 johnson
 
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emdsapmgr

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Re: 90 hp v4 johnson

Not sure just how you have the new pump mounted: The pump you purchased is meant to be mounted to the side of the block in order to get the crankcase pulses in order to make the pump function. The VRO pump which you took off used a separate crankcase hose to provide the crankcase pulses to the pump. Those are two different types of pulse methods. If you have the new pump mounted directly to the side of the block and you have blocked off the old pulse hose, the new pump should work. I'd prefer to put a 3-port pump in it's place-one that uses the existing VRO pulse hose. That pump is part number: 438559.
 
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James R

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Re: 90 hp v4 johnson

emdsapmgr is quite correct. I cannot see from the block drawings if there is facility to mount the pump you purchased. I do know that a 1985 120 and 115 I did recently and a 1990 I have done and in the shop now does not provide for the case mount pump. The 428559 is the pump and can be found listed under 1975 135HP motor. Simple to mount. Use new hoses and bolt it to the old VRO mount bracket.
 
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thomasonbunch

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Re: 90 hp v4 johnson

hello the pump i put on the motor is a two port fuel in and fuel out do you think by not using a three port is causing the motor to start and then die it only runs about 2 or 3 seconds and dies if you try to give it throttle it acts like it floods it and then a takes little bit to get it to start and then die and another question i check the spark one day and could not see it so we decided to leave it alone and wen out there another day and i bought one of those spark checkers and could not see it in the day but can see it at night
 
J

James R

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Re: 90 hp v4 johnson

If you are referring to the light bulb style tester they are difficult to see in daylight. The better tester is the spark gap tester with which you can judge the strength of the spark.
You have not said if you have solved the fuel pump issue. Is your two hose pump correctly facilitated or do you need the three hose model that we all use.
 
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