Runs great on hose, Dies under load

Daviet

Fleet Admiral
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Sep 24, 2008
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Re: Runs great on hose, Dies under load

Splice in a pressure guage and run it, watch the fuel pressure.
 

Just-in Time

Cadet
Joined
Aug 27, 2010
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Re: Runs great on hose, Dies under load

Splice in a pressure guage and run it, watch the fuel pressure.

Please excuse me but im not quite sure what this means. you mean splice it in the fuel line right? any particular place?
Also, assuming i see some variance, what do i do with this information and how does it help me discover the ultimate problem?
thankyou kindly, Justin
 

Daviet

Fleet Admiral
Joined
Sep 24, 2008
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8,958
Re: Runs great on hose, Dies under load

Yes, splice it in the fuel line that runs from the pump to the manifold.
 

Just-in Time

Cadet
Joined
Aug 27, 2010
Messages
16
Re: Runs great on hose, Dies under load

Yes, splice it in the fuel line that runs from the pump to the manifold.

oh ok i see now. and when the engine has the problem, check the pressure gauge and look for low pressure. this will isolate the problem to the fuel pump. sounds like a good idea.
just need to buy a pressure gauge.
thankyou
 

Daviet

Fleet Admiral
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Sep 24, 2008
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8,958
Re: Runs great on hose, Dies under load

Correct, I know of people that have installed a guage and left it in the system.
 

Just-in Time

Cadet
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Aug 27, 2010
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Re: Runs great on hose, Dies under load

Alright I think I'm getting close to finding the problem. It has more symptoms now which should make it easier to eliminate a bunch of things.
Put the boat in the water to test some more and this time the problem happened immediately. At first when i would push the key in to prime, the rpm's would increase slightly. Seems like it would be a lack of fuel problem. however, later (maybe a couple hours) under the same circumstances, pushing the key to prime caused the engine to die.
At one point we couldnt get the engine to run above idle at all for about an hour. it would once again start somewhat easily, only idle and then die when given throttle. What eventually helped it was putting it in neutral, pumping the fuel, and manually increasing gas at the engine to cause it to run at higher rpms. After that it was fine and ran in gear again.
it may sound weird but it really seemed like the waves were giving the engine a hard time. 2-3' waves submersing the engine above upper exhaust holes seemed to make it die when in idle after just starting.
I checked the floats on the carbs and they seem fine.
Also, I did notice something worth noting but im not sure it would cause this. When pumping the fuel and trying to start the engine, fuel would squirt a little out of the top of the primer on the engine. When the primer is on and the fuel is pumped, it leaks out of the top of the primer. when its not on it doesnt leak unless trying to start the engine. a little confusing, i know.

is it possible for this to be an electrical problem? how would i troubleshoot that? Sorry for the long post. thankyou!
 

Daviet

Fleet Admiral
Joined
Sep 24, 2008
Messages
8,958
Re: Runs great on hose, Dies under load

You need to repair the fuel leak to eliminate any chance of the fuel system to suck air. What is you idle set at?
 

Just-in Time

Cadet
Joined
Aug 27, 2010
Messages
16
Re: Runs great on hose, Dies under load

You need to repair the fuel leak to eliminate any chance of the fuel system to suck air. What is you idle set at?

OK. Not sure what it's set at, I dont have a tach. My mechanic adjusted it for me last time it was in the shop.
 
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