1980 Trailfire engine problem I can't pin down

[mwking]

I'm having a problem with my 1980 340 Trailfire that I can't seem to nail down. The sled is very low mileage and I had the opportunity to buy it from the original owner. It's is in very good but not perfect condition. It is a great survivor so I decided to go through it completely but not restore it or improve it cosmetically. The engine has been gone through and has new gaskets and seals, the fuel tank was cleaned and the fuel lines and filter were changed. It starts up fine cold but does not want to idle. It will rev up and run for a few minutes if you keep the rpms up. It acts like it is getting too much fuel and flooding out. It will stall and is difficult to restart. If you hold the throttle open and play with the choke you can usually get it running again but it quickly stalls out. I have replaced the choke plunger and checked the adjustment. The fuel pump was rebuilt. I have cleaned the carburetor several times and actually tried another with no improvement. I also swapped on another choke cable and switched the coil in case it was an ignition issue. So far nothing has helped. Not sure where to go from here other than to keep swapping parts and hopefully stumble on the cause. Just wondering if anyone has run across anything like this?

Thanks,


Murray

[robtan88]

Murry. From what you are describing, I am leaning still toward an over-fueling/ flooding issue from your description. Also wondering if you have a sealing issue between the two cylinders when you put the crank and crank case halves back together, meaning internal leaksge between the two crank case halves...Rob.

[ljm]

Murray

Welcome back!

When you pull the starter rope. Does it ever want to kick and pull the handle out of your hand?
Have you replaced or rebuilt the fuel pump?

Lloyd

[mwking]

Thanks for the replies.

I did rebuild the fuel pump and it has never kicked back on me. About the sealing between the cylinders, I had never thought of that as being a possible source of the problem. How would that cause it?

Lloyd, I have been away for a while. I actually finished the rebuild on this sled almost two years ago. I ran into these problems and set it aside. I started a new job and work was really busy and I never looked at a sled last winter. Things are still busy at work (in a good way) but I am trying to make some time for the things I like to do.

Murray

[ljm]

Murray

I had a sled that ran like similar, but it would pull the handle out of your hands when it kicked. It was a CDi. I would be tempted to try a different one.

[mwking]

I was getting frustrated not being able to find any fuel issues that's why I swapped the coil. Make sense to try the CDI next.

Thanks, I have a little more hope now.

Murray