87 50HP VRO Evinrude - Could this be my problem?

FishAtFive

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Sep 3, 2025
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It's just a matter of ruling stuff out. I've now ruled out the carbs and entire ignition system. I'm thinking if I can find out the ideal starting RPMs I can test that and rule out the starter and battery. If I squeeze the bulb that doesn't rule out the pump, it could just be compensating for a bunch of different things like poor crankcase pressure, issue with choke solenoid, slow start speed. Unfortunately I only get a small amount of time each week to work on it. I work a full time job, go to night school and have 3 kids, cub scouts, sports, etc.

I've also found that testing on the muffs is useless. I need to fill a tank and test on that, which takes time.
 
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saltchuckmatt

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Jul 19, 2019
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It's just a matter of ruling stuff out. I've now ruled out the carbs and entire ignition system. I'm thinking if I can find out the ideal starting RPMs I can test that and rule out the starter and battery. If I squeeze the bulb that doesn't rule out the pump, it could just be compensating for a bunch of different things like poor crankcase pressure, issue with choke solenoid, slow start speed. Unfortunately I only get a small amount of time each week to work on it. I work a full time job, go to night school and have 3 kids, cub scouts, sports, etc.

I've also found that testing on the muffs is useless. I need to fill a tank and test on that, which takes time.
Muffs are not useless...and, if you have diaphragm damage to the fuel pump that's the test.

Best of luck to you, your obviously a thinking man but perhaps in this moment your "overthinking"
 

FishAtFive

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Muffs are not useless...and, if you have diaphragm damage to the fuel pump that's the test.

Best of luck to you, your obviously a thinking man but perhaps in this moment your "overthinking"
The handful of times I thought something was fine in the driveway only to be dissapointed at the ramp tell me otherwise. I'll happily swap 20 minutes of prepping the test tank versus 2 hours back and forth to the ramp. I've taken apart the fuel pump and inspected it awhile ago, one of the first things I did.
 

FishAtFive

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Yep , all the hundreds of thousands of peeps all over the world that use them are just wrong . :rolleyes:
They are actually a very handy tool ........but you do have to know how to use them:)
I use them. Just saying for serious diagnostics that require load similar to that of being in the water, using the muffs can skew the results and leads to false diagnostics. If ya'll going to get nitpicky over every little statement then that's your time to spend, I guess.
 

saltchuckmatt

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I use them. Just saying for serious diagnostics that require load similar to that of being in the water, using the muffs can skew the results and leads to false diagnostics. If ya'll going to get nitpicky over every little statement then that's your time to spend, I guess.
Look, we all need to take a big breath. What Mc tool is explaining as you can do lots of things on muffs but you can't do everything. A test tank is great but not everybody has one. I do and I have test props to go in it. If you're talking about a barrel full of water that's not a test tank. We all understand that once you put a an outboard on load, now you've got a whole different set of rules.

This is post 67 which is crazy. You diagnosed that your primer function is not working properly. Solve that, andyour golden. Could it be the crank seals?? it's possible but not probable.
 

FishAtFive

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Crank seals are low on my list. When I first got the motor it was literally spraying fuel out of the primer valve it so I replaced with with an Amazon special...but I kept the original. I did not know any better. Before I even mess with it I will see if I can recreate the condition and see what happens when I turn the red valve manually. I might have done that this past weekend but I can't remember. I was just besides myself that I could rule out so many things with that one simple test of unplugging the primer hose, and then I ran out of time. I knew it was at least somewhat working because if I pressed the key while it was running it would accelerate then stall the motor. Getting closer!
 
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