# 1984 evinrude VRO 40hp overfueling



## gotmuddy (Nov 24, 2010)

I have a 40hp on my 16x48 and WOT it will only go 16mph. It has good compression, good fire(haven't hooked a timing light up yet though), the fuel pump has been retrofitted to not use oil injection, and the priming system is set correctly. Could the primer solenoid be dumping fuel constantly?


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## gouran01 (Nov 24, 2010)

I had a very similar problem on my 87 rude. The choke was staying engaged and sucking about 3 times the fuel into the engine. I disconnected the choke from the ignition (key) set up and wired it directly to a push/pull toggle switch and coulda swore I had a brand new motor back there! I think that it's suppose to shut it self off at a certain temp, and there is a replacement part for that sensor but for the age of the motor, you can't beat a 3 dollar switch!


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## Pappy (Nov 24, 2010)

A very common mistake coming from people wiring up their own motors is to hook up the purple/white wire in the harness to key on hot power. Should be the purple wire on the "I" terminal. If this has been done then the primer solenoid assembly is toast and fuel will free flow through the assembly. With the engine off and the key on you should be able to hear crisp audible clicks with you pushing in the key switch repeatedly. If you do not hear these clicks then the primer has failed, ground wire is open, or it has been wired incorrectly. Quick checks to make is to take a pair of needle nose pliers and gently pull one of the small diameter hoses off the primer while the engine is running or you are pumping the bulb. If fuel is coming out then take a test light and see if the purple/white on the primer is hot while the key is on and the key switch is not depressed. If so, go to my first sentence and fix the problem. Second way to check is to pinch off the larger line to the primer while running and see if the engine picks up. The primer does not stay on until a certain temp, the Purple/white should only be hot when the key is on and the key switch is depressed.
Third..........the red manual valve should be facing back along the body of the primer, not sticking above it.
Below is how your key switch should be wired. There is no need to add a push button switch!

IDENTIFIER FUNCTION WIRE COLOR CODE CONNECTS TO 
B BATTERY Red with Violet stripe Battery positive via fuse 
A or I ACCESSORY or IGNITION Violet Accessory loads; engine ignition 
S START Yellow with Red stripe Engine starter solenoid coil 
C CHOKE Violet with White stripe Engine primer solenoid coil 
M (raised) MAGNETO Black with Yellow stripe Engine ignition kill circuit 
M MAGNETO Black Engine chassis or battery negative


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## gotmuddy (Nov 28, 2010)

thanks for the reply pappy, very informative. That makes sense because when you pull the fuel hose off and run the motor out of fuel for about 3 seconds it runs perfect, then it dies.


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## gotmuddy (Nov 28, 2010)

I plugged the hoses for the carbs and pumped thebulb. It appears that its working fine. It doesn't let fuel out until you push the key in. One jet was stuck in the carb bowl but I was able to get the other out. It says 38d on the jet. How can I find out if the let's are the correct size?


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## blunt (Nov 28, 2010)

orifice plug 38d is for a 1986 -1988 40hp .. 39d is for a 1984 40hp...


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## gotmuddy (Nov 28, 2010)

How big of a difference would that make? Maybe I have a '86 instead of a '84...


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## blunt (Nov 28, 2010)

honestly I doubt it would make a difference. Your motor may be a little newer or maybe just the carbs are. either way I would say it's the correct jet for a 40hp.


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## Pappy (Nov 29, 2010)

Try clamping off the supply line to the primer while running the engine. See if that makes a difference. The small difference in jet size should not make a difference unless someone has been playing with drillbits with your jets.


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## gotmuddy (Nov 29, 2010)

Pappy said:


> Try clamping off the supply line to the primer while running the engine. See if that makes a difference. The small difference in jet size should not make a difference unless someone has been playing with drillbits with your jets.




when the fuel is unhooked the motor runs the same until it is almost out of fuel, then it runs perfect for about 3 seconds before it dies.


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## Pappy (Nov 29, 2010)

Yes, I read that several posts up. 
Now, at the RPM the issue is occuring at, clamp off the supply line to the primer and see if the engine picks up. Could be that at higher RPM more fuel pressure is building and becomes enough to free flow through the pump.


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## gotmuddy (Nov 30, 2010)

when you say primer do you mean the bulb on the fuel line or the fuel pump up on the motor?


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## Pappy (Nov 30, 2010)

The one on the engine. We are trying to see what is passing excess fuel when it shouldn't be. There is no pressure in the primer bulb when the engine is running.....only vacuum as the engine's fuel pump is sucking fuel through it.


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## 89Suburban (Nov 30, 2010)




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## gotmuddy (Nov 30, 2010)

I wont be able to check it with it running until this weekend.


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## gotmuddy (Dec 4, 2010)

I pulled the fuel pump apart and found a pinhole in the diaphram. guess I found my problem.


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## gotmuddy (Dec 19, 2010)

Well rebuilding the fuel pump helped a little but it still isn't fixed. I put new plugs in it but that didn't help. I noticed quite a bit of smoke


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## gotmuddy (Dec 21, 2010)

found the problem, the top coil was going bad.


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