1957 Evinrude Fleetwin Carb Problem

[yesizmatt]

My evinrude will not run very good at all. If I do get it to start (take around 5-10 pulls) it will only stay running for around 10-15 seconds, and can not idle low, or be put into gear without it dying. I have replaced coils, points, and spark plugs so those are not the problem, but I believe something went wrong when I re-built the carb. I have a few pictures to show if anything looks wrong which in particular I was wondering about the larger green gasket type washer and if it is in the correct spot, because in my diagram their is not one their, but others have told me that's where to put it. Any ideas on how I can get my motor running??

 

[nwcove]

Re: 1957 Evinrude Fleetwin Carb Problem

the green boss gasket is in the right spot. when you put the bowl on, do you need to screw it down to get it to contact the bowl gasket? the green boss gasket should hold the bowl up a bit before you tighten the screws. still running the pressure tank?

 

[yesizmatt]

Re: 1957 Evinrude Fleetwin Carb Problem

Yes the boss gasket does hold the bowl up a bit before it tightens. I have installed a fuel pump to run with newer tanks, could the problem be their? The pump is a Mikuni Fuel Pump.

 

[nwcove]

Re: 1957 Evinrude Fleetwin Carb Problem

where are you getting the pulse for the pump from? heres how it is normally done on that motor

 

[yesizmatt]

Re: 1957 Evinrude Fleetwin Carb Problem

That is where I have the fuel pump hooked up to give it a pulse

 

[nwcove]

Re: 1957 Evinrude Fleetwin Carb Problem

compression numbers? spark jump a 1/4 open air gap? what does it do before it stalls?

 

[HighTrim]

Re: 1957 Evinrude Fleetwin Carb Problem

Start with compression. What is it?

As stated above, next ensure the spark will jump a 1/4" open air gap with a bright blue ZAP!!

Next remove the fuel line, direct it into a container, and pull over or start. Steady stream of fuel coming out from fuel pump?

Ensure float floats. Ensure it is not getting hung up on the gasket. Ensure needle is coming off of seat.

Before installing carb on motor, do a blow test on it. Right side up, you should be able to blow into the fuel inlet with ease. When you flip it upside down, you should not be able to.

 

[yesizmatt]

Re: 1957 Evinrude Fleetwin Carb Problem

I have taken the carb off and noticed their is more than one carburetor mounting gasket. Would this be a problem?

 

[nwcove]

Re: 1957 Evinrude Fleetwin Carb Problem

you need to use the one that is the right size for the carb/intake. the kits for that motor include parts for 3hp up to 18hp ( maybe more)

 

[yesizmatt]

Re: 1957 Evinrude Fleetwin Carb Problem

Ok so I have taken off the float and needle that came in my carb kit, and replaced it with the original ones. I started the motor right up and runs on nearly every pull. What could be the problem with the new set I got in my carb kit? Also now when you prime the motor until the ball gets hard, it will run well and then die out or not go up to its full potential when twisting the throttle to fast. Once the motor is off, the ball on the gas line is not very hard and when I prime it again, I can hear this noise in the carb like hissing or something. Their is no gas leaking, so it must be air coming out somewhere or just the carb re filling up? Would this problem be why it can not go to its full potential when it comes to speed?

 

[oldboat1]

Re: 1957 Evinrude Fleetwin Carb Problem

hissing could be the air outlet to the two line pressure tank, if hasn't been completely plugged for use of a fuel pump. (hissing could also be coming from the fuel pump connection, connector from the tank, or something related to the fuel pump installation/operation.) Sounds like the new needle wasn't operating right, but would just stay with the old float and needle if that's working. Keep the new ones in reserve. Assuming you found the compression was OK, it sounds like the running issues could be as simple as properly adjusting the high speed and low speed needles -- might reset those. If you can't get an idle, it's possible the chamber on top of the carb wasn't completely cleaned when the carb was done.

 

[HighTrim]

Re: 1957 Evinrude Fleetwin Carb Problem

That hissing sound is normal when priming the fuel bowl. It is air, and is usually heard right before the fuel starts filling the bowl. Did you then hear the liquid fuel filling?

Now, as stated, tune the needles. Let us know if you need help with this.

 

[yesizmatt]

Re: 1957 Evinrude Fleetwin Carb Problem

I blocked one of the air outlets with a vacuum cap when I did the conversion. If this did not make a good seal could that be why the ball is not staying hard after the motor runs for a bit?

 

[HighTrim]

Re: 1957 Evinrude Fleetwin Carb Problem

Im confused with your conversion? You blocked one of the air outlets?

Did you modify the intake manifold, then use the old pressure line as a pulse?

Can you show us pics of what you did.

The bulb is not meant to stay hard. It gets hard when the fuel bowl fills, then once running it simply turns into a one way valve, not supposed to stay hard.

 

[nwcove]

Re: 1957 Evinrude Fleetwin Carb Problem

that is a bit confusing? sounds as tho the op did the mods to the intake and tapped the bypass cover??

 

[yesizmatt]

Re: 1957 Evinrude Fleetwin Carb Problem

In all of the conversion tutorials you are suppose to block one of these passage on this thing behind the carb I don't remember what it is called. I have tried running the motor again following the tutorial on this website on how to tune the needles. My motor is running very rough again and when I finally get it into gear and twist the throttle it won't react, and then in will all of a sudden jump up to very high rpm, then dies completely. I don't know what to do but I am just considering taking it somewhere to have it fixed because I have been troubleshooting this motor for months now. Can't seem to find the problem to fix this motor.

 

[nwcove]

Re: 1957 Evinrude Fleetwin Carb Problem

are you tapped into the bypass cover like in the pic i posted.....and do you also have the intake modded? there is absolutely no reason to mod the intake on the 7.5 hp's. the tutorials you watched were more than likely for the 5.5hp motors, as they dont have the removable bypass covers.
by your description, it sounds like the motor is running out of fuel. did you do the fuel pump test described by hightrim?

 

[yesizmatt]

Re: 1957 Evinrude Fleetwin Carb Problem

Yesterday my buddy and I took the hose that goes from the fuel pump to the carb off and pulled the cord. It was not a steady line of fuel that came out of the fuel pump. It was more drippy and definitely not a steady line coming out.

 

[yesizmatt]

Re: 1957 Evinrude Fleetwin Carb Problem

I watched this tutorial and for the most part followed this tutorial exactly. http://m.youtube.com/watch?v=FtG4M7ye1N8

 

[nwcove]

Re: 1957 Evinrude Fleetwin Carb Problem

definitely need pics of the fuel pump setup! you can bypass all that stuff and try to run the motor for tuning purposes and rule out carb issues tho.