fuel delivey problem

[doghunter9]

Good day guys

OK I got a 94 50hp johnson with vro. About 2 weeks ago i was using my boat, every thing was fine, trailered it home, was sitting for about 1 week, than launched it and I never got out of the harbour, I had to keep priming the bulb(fuel pump Not working?)

Ok, Is it possible that the fuel pump broke in my drive way, or a line is leaking, It is about 3 km to the slip way. so i doubt it crack in transit. also it is about -5 degrees celcius here. my lines have frozen and cracked? I cant fined any leaks.

If i want to switch to standard premix pump is there any troubling doing that. Anybody know the pt # for this pump. I am looking for the ones that have a pulse tube not the one that bolt directly to the crankcase.

I had a old pump of a 84 65hp, I tried that, it was better but not perfect, so i rebuilt it but broke it in the process. So I want to try to get a new one like this but an unsure if it will work? much cheaper then a VRO.

Any input is welcome


Is there any issues with flow if a 65hp pump on a 50Hp?

 

[stanky]

Re: fuel delivey problem

... it is about -5 degrees celcius here...

Any input is welcome

You need to move someplace warmer.

 

[doghunter9]

Re: fuel delivey problem

You need to move someplace warmer.

Nope I like it just fine a little cooler would actually be nice(longer snowmobile season) Like my signature says

 

[kenmyfam]

Re: fuel delivey problem

Either air getting into the fuel lines or a failing pump. Did you check all the lines yet for leakage ??

 

[kenmyfam]

Re: fuel delivey problem

Test pump by removing item #24 at the fuel manifold (item#10) end and run the hose into a container. Put muffs on to save impeller and crank the motor and watch what is going into the container.
Regular strong spurts = healthy fuel pump.
Strong spurts to begin with and tailing off = pump starting to fail.
Trickle or next to nothing = fuel pump failed.
This is assuming that there is no major air intrusion from the hoses / connections.
Use this link and plug in your model and year to find the diagrams.

http://shop2.evinrude.com/ext/index.aspx?s1=bf6ad09c53cead335fcfd8a6471c0f7f

Good Luck and keep us all posted.

 

[kenmyfam]

Re: fuel delivey problem

Here's a link to a conversion job that may help you.
Remember though, you can rebuild the fuel side of your existing pump and that may well be a more economic repair.

http://forums.iboats.com/showthread.php?t=265363&highlight=now+pre+mixer

 

[tashasdaddy]

Re: fuel delivey problem

this is a 2004 50 hp that has been converted to a premixed pump. route your fuel hose to the pump, and plug the pulse line to the block. there is a 1/4 inch plug on the side of the block, remove and mount new pump.

 

[doghunter9]

Re: fuel delivey problem

ok Heres the situation.

Took out the VRO put in the premix pump, rebuilt the pump did a blow test. I can blow back thru the pump but it is restricted compare to the correct flow direction?

I removed the pump discharge line and replaced them with clear one so I could see whats going on. Prime the carbs is fine, First right up then after 30 secs I start to see air in the lines and she dies. When she dies I see all the fuel run back form the carb to the manifold replaced with air. I assume this is becuase the needle is down because the bowl is emtpy. Correct???

SO After 2 pump and a complete rebuild one one still no fuel to the carbs? I by passed the filter and went directly to the pump withe the primer line? triied 2 differnt primer lines.

Could I have a partial restriction in my tank that allows priming but stops the pum from lifting.

PS with the tank at the same level as the pump it dont really help.

 

[ezeke]

Re: fuel delivey problem

Are you now using a conventional lift pump or the non VRO/OMS that looks like a VRO/OMS pump?

Did the primer bulb collapse?

Try running on a portable tank with a different hose and primer bulb?.

 

[doghunter9]

Re: fuel delivey problem

the blub dont collape jus tlose its pressure once the motor is started, I can pump it up again and catch the motor before it dies but I have to do it slow. If I Pump it quick I kill the motor. I tried two differn blubs but never tried a different tank.

 

[ezeke]

Re: fuel delivey problem

If the pump is a lift pump and is mounted as shown in TD's photo, make sure that the gasket between the pump and the engine is airtight.

I think that you have a float valve that is sticking open.

 

[doghunter9]

Re: fuel delivey problem

another bit of info I should provide, Today in the harbour at WOT the motor is barely running and you can pump the blub up but no real change, but if you really squeeze it you get a little surge form the motor.

 

[ezeke]

Re: fuel delivey problem

The primer bulb and the fuel pump should only fill the float bowls with fuel. The pistons then create a vacuum that pulls fuel from the float bowl.

If squeezing the bulb allows fuel to reach the engine directly, you have either a ruptured fuel pump membrane, a float valve that is stuck open, or a primer solenoid valve that is open.

 

[doghunter9]

Re: fuel delivey problem

When I see the air develop in the carb lines I can rev the engine and get the fuel to move towards the carbs but as soon as you let of the throttle the fuel the falls back to the fuel pump. Does this indicate a fuel pump or pulse problem.

The pump is a conventional lift pump that uses a pulse line, not the one in the pic above?

 

[ezeke]

Re: fuel delivey problem

It indicates either an air leak, a primer solenoid valve open, or a float valve not closing.

 

[doghunter9]

Re: fuel delivey problem

bad diaphram in the carb was the problem, causing the bottom cylinder to lose it power, spray fuel in through the throat and it picked right up.

Thanks

Scott