johnson 1991 v4 90hp wont start

arthurj12

Petty Officer 2nd Class
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Mar 14, 2012
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106
hello my v4 90hp wont start without primer solenoid on after its starts i turn primer back to normal it will idle for 10 mins then die if i pump the fuel line it helps so im thinking fuel pump iv cleaned carbs replaced thermos anyone have a good thought about it need some input thx
 

emdsapmgr

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Dec 9, 2005
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11,551
Re: johnson 1991 v4 90hp wont start

The topic header says it won't start, yet you indicate it will run. Not sure just what you mean regarding the primer solenoid. You don't "turn it back to normal" during regular operations. To prime the engine for cold start, you push in on the key when it is in the on, or start position. That will inject a small amount of extra fuel direct into the carb throats. That's the choke operation. There is a red lever on the side of the solenoid, which is not to be moved during normal operations. That red lever should always be kept parallel to the length of that solenoid. You are performing a good test of the fuel system by constantly priming the hose bulb. That action forces extra fuel into the carb bowls. If the engne runs "normally" as long as you prime that hose bulb, you've got a fuel delivery issue. Very well could be a weak fuel pump. (Or fuel restriction-like a bad hose, sticking anti-siphon valve, etc.) The issue with a weak pump is that it may provide some fuel to run the engine, but maybe not enough to sustain it-this usually is a high speed WOT problem, but surely could occur at idle if the pump is weak enough.
 

toddschubert

Chief Petty Officer
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Sep 3, 2011
Messages
504
Re: johnson 1991 v4 90hp wont start

Do you have an external filter? Did you check screen on Pump?
Second EMD on red leaver...leave it alone...unless your trying to pull start or mist it.
 

arthurj12

Petty Officer 2nd Class
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Mar 14, 2012
Messages
106
Re: johnson 1991 v4 90hp wont start

ok will not touch red lever and ill check my filters the key primer makes a sound when pushed in but doesnt help
 

Joe Reeves

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Feb 24, 2002
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Re: johnson 1991 v4 90hp wont start

hello my v4 90hp wont start without primer solenoid on after its starts i turn primer back to normal it will idle for 10 mins then die if i pump the fuel line it helps so im thinking fuel pump iv cleaned carbs replaced thermos anyone have a good thought about it need some input thx

I understand what you're saying about turning the RED lever of the primer solenoid to the manual override position, then turning it back to the normal automatic position, also also the priming the fuel primer bulb statement.

What you've had to say indicates that the fuel pump is failing OR the pressure line that leads from the pump to the crankcase is cracked, broke, leaking.

The proper and normal starting procedure for that engine incorporating the Fast Start feature and the fuel primer solenoid is to..... Pump the fuel primer bulb up hard, turn the key to the START position and push the key in at the same time to engage the primer solenoid, and hold the key in until the engine fires and starts, then release the key to the ON position.

It may be necessary to bump/push the key in momentarily from time to time to keep a cold engine running until it warms up.
 

wired247

Lieutenant Commander
Joined
Oct 8, 2011
Messages
1,557
Re: johnson 1991 v4 90hp wont start

Did you clean the carbs before or after it wouldnt start and run?
 

arthurj12

Petty Officer 2nd Class
Joined
Mar 14, 2012
Messages
106
Re: johnson 1991 v4 90hp wont start

ok thx alot ill check the pressure line is there rebuild kits for the vro2 pumps available if need be
 
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