1963 Big Twin 40 HP Fuel Problem.

[vwfoolwhy]

1963 Big Twin 40 HP Fuel Problem.


I picked this boat up at the beginning of the year and it's been a slow summer long rebuild project.

A few weeks a go it was finally go time. So I set out for it first run. Unfortunately it didn't go all that well. The only way I could keep it running except at idle was to pump the primer bulb so it would fill the clear fuel filter. It would run great all the way up to full throttle when pumping.

So I decided the fuel pump needed rebuilding.

I ordered a pump rebuild kit and carb kit. It didn't need the carb kit but it was cheap and not any more for shipping.

Received all the parts and installed and adjusted to the manual (on CD but still the manual). Started and ran fine on the ears and even reved it up a few times.

Put the boat back in the water and started off and even got up to FT for a short time. Again the fuel filter would empty again and it died. Pumped the bulb a few times and it fired right back up. It will keep up at no wake speed but not anything over with out pumping.


"Now for my ?"

1- Do you believe it could be the fuel pump. Even if it pulls fuel from the filter and it also squirts a steady stream of fuel up to the carb (Removed fuel line at carb and cranked motor fuel shot right out)

2- Do you believe it could be a bad fuel line from tank to filter or filter to pump.

I plan on replacing the fuel bulb and line and another new inline filter, but I wanted to see what every one else's thought on this where as well.

The carb is set perfect great throttle response and start response.

Fuel mix is 40:1 and NGK B6HS plugs look great after run time.

Mike
Methuen, MA

 

[rolmops]

Re: 1963 Big Twin 40 HP Fuel Problem.

There is a good chance that there is a hole in your fuel line.This will make it suck air instead of fuel.Replace your fuel line not just from the tank to the engine hook up,but also the lines that go to the fuel filter and pump.The fuel filter in the glass should be enough.Do not add an additional inline filter,it just makes it harder on the pump.
Do replace those NGK plugs with Champions.They are made for this engine. J4C is what you need.
The mix you need to use is 1:50.
Good luck!!

 

[tashasdaddy]

Re: 1963 Big Twin 40 HP Fuel Problem.

what about the gasket or the fuel bowl, they go bad and leak air, thus the pump can't pull fuel.

 

[vwfoolwhy]

Re: 1963 Big Twin 40 HP Fuel Problem.

All gaskets where replaced in the pump and carb.

Tomorrow I'll be replacing all the fuel lines and I'll try eliminating the inline fuel filter.

I had replace this filter and reinstalled only because the previous owner had one installed there.

The filter in the pump bowl was missing but now has one.

As far as the NGK Plugs they are a personal preference for me over Champions so I'll stick with what works for me.

As for the ratio this being a 63 it's said to run 24:1 and on the 64 they went to 50:1

I'm running 40:1 and the plugs look great so 40:1 will work for now.

Thanks for the suggestion I'll be sure to let every one know how it turns out.

Mike
Methuen, MA

 

[dave havoc]

Re: 1963 Big Twin 40 HP Fuel Problem.

hey Mike I also have a '63 40 hp johnson- I was wondering if you can tell me how the fuel lines are set up from tank to carb. I bought the motor and there were no fuel lines. I posted a tread today with the same question. Thanks man.

 

[vwfoolwhy]

Re: 1963 Big Twin 40 HP Fuel Problem.

wow I'm really bad with re-posting.

It ended up being the primer ball as one of the one way valves was gone.

all new fuel lines with primmer set up with no in line fuel filter and it ran like new all summer.

Had more fun with the MFG and the 40 Evinrude then i did with the BW rage 15.

 

[riker64]

Re: 1963 Big Twin 40 HP Fuel Problem.

There is a good chance that there is a hole in your fuel line.This will make it suck air instead of fuel.Replace your fuel line not just from the tank to the engine hook up,but also the lines that go to the fuel filter and pump.The fuel filter in the glass should be enough.Do not add an additional inline filter,it just makes it harder on the pump.
Do replace those NGK plugs with Champions.They are made for this engine. J4C is what you need.
The mix you need to use is 1:50.
Good luck!!

great idvice