Starting new thread for same old problem.....

[Brad]

HAd a thread going on fuel pump and carburator, but am still having trouble. Spent some time today trying to find out what could be wrong?
My Son's M135 will start right up, and seems to idle fime. I was thinking fuel all along, but then maybe condenser? Would run down the road just great, then shut off, but then start right back up and run fine for a while? Then shut off again.??
So here is what I did today. It started up and I was feeding it gas, just above idle. It strted to sputter and miss, and shut off. I was giving it enough gas that would seem to be the same as if cruising on level road at medium speed. It would then start right back up, and after a couple minutes playing with the throttle I could get it to stall again.
Then I noticed something. After it stalled, I could not hear the fuel pump running. If I shut everything down and turned the power back on the pump would run. But after it would stall, no pump running. However once after a few minutes, the pump just came back on by itself. I had not shut the ignition or power switch off.
Does the fuel pump shut itself down if there is enough fuel un the float of the carb?
Also, I took the top off the carb and the float area was full of fuel?
I have a couple sets of points and condensers ordered, and am going to order a set of plugs, But I am really perplexed???
Thanks for any help in advance

 

[NDT]

Pump runs any time the ignition is on.

 

[williamh]

I had an m135 and when the condenser was bad it had no spark , it didn’t just die it would start missing real bad and burn the points. And yes the pump should run always when turned on. You might want to buy a cheep electric fuel pump and put it on , like $15.00 on Amazon. Should be able to pull past the pump or use a fuel can with the pump and connect to the carb to see if the issue goes away.

 

[rustystud]

I had an m135 and when the condenser was bad it had no spark , it didn’t just die it would start missing real bad and burn the points. And yes the pump should run always when turned on. You might want to buy a cheep electric fuel pump and put it on , like $15.00 on Amazon. Should be able to pull past the pump or use a fuel can with the pump and connect to the carb to see if the issue goes away.

Agree with "williamh" about the condenser. When I was a young man all gasoline vehicles had "points and condensers" . No such thing as HEI or any electronic ignition. One major "give away" in your statement was the engine would fire back up after stopping. The condensers job is to "absorb" the electrical current from the points, and discharge it to ground. When they become "saturated" they can no longer absorb any current. When the condenser becomes old it can no longer quickly discharge the current and becomes saturated. So when it shuts down it discharges it's "charge" and can quickly restart.

 

[Brad]

Thanks so much to all. I was looking at elec fuel pumps on line. Some said that they would stop at a certain high pressure. That's why I thought perhaps that is what mine is doing?
Also, there are what appear to be, three "condensers" in this distributor? Although I believe I know one of them is actually a resistor to lower the voltage to the points?
After your description of what that condenser is supposed to do, it sounds like that may be the trouble. Sure hope so.
Thanks again, and please keep the help coming?

 

[NDT]

The condenser that dies is the one right next to the points on the breaker plate. Mine once crapped out at 58 mph and the engine backfired so severely it blew my muffler into pieces. Happened late at night on I-45 downtown Houston elevated. I was able to limp to a safe location.