SA 200 suddenly dies

[rybot]

I am not sure if this is the right place to post my question. I have a 1978 sa 200 that was rebuilt and then sat for over 20 yrs. Just finished cleaning the carb/fuel tank and replacing fuel lines and filters. Starts up and runs great. welding is a pleasure. However.......randomly while idling or even during welding it will just shut off. I originally suspected ignition problems since there is no sputtering or struggling before it dies. It's just like you switched off the ignition. However, I have verified with a spark tester that ignition stays on and spark continues until the engine stops turning.

Thoughts? Newly rebuilt carb. etc.

[rybot]

More info:

After it dies it will usually start right up but I do have to choke it and occasionally choking is not enough and I have to put my hand over the intake while someone starts the machine (aggressive choke). Once running again it runs without problem for several minutes until it happens again.

[G-ManBart]

If you're sure it's not ignition it can only be fuel. I've seen something similar happen with tractors....something in the fuel tank/filter/strainer that normally floats will get sucked in, cause a blockage, then float away after the suction is gone so the engine will restart and run fine. The need for extra choke to get it restarted sort of points to that as well...you're having to enrich the mixture by limiting air.

[M J D]

There should be a sediment bowl on there. Remove as much gas as possible then pull out the sediment bowl assembly. Check the screen and run a wire inside the opening to be sure it's clear. Could have some build up between the needle- seat and the fuel inlet.

[Insaneride]

If you're sure it's not ignition it can only be fuel. I've seen something similar happen with tractors....something in the fuel tank/filter/strainer that normally floats will get sucked in, cause a blockage, then float away after the suction is gone so the engine will restart and run fine. The need for extra choke to get it restarted sort of points to that as well...you're having to enrich the mixture by limiting air.

Could be loss off compression tho

Bolts headsteads could of loosened
No?

[M J D]

Could be loss off compression tho

Bolts headsteads could of loosened
No?

If that was the case it would run like crap before it died or probably not start in the first place. Simple check would be to see if it has decent suction on the air inlet when cranking. Ignition coil can cause an engine to randomly die, but they will generally misfire before shutting down

[duaneb55]

Some SA200 carbs have a filter screen integral to the inlet elbow fitting. If you haven't checked to see if that's the case and that it's clear I would look there.

[123weld]

ur last sentence might kill this theory, but, yrs ago a 65 hs wisc eng of mine was dieing quickly like u described. finally found out that once things sorta got up to temperature, the condenser on the comvetional type distributor was acting up/going bad. id think same thing is possible w/ a mag., i have fuel line from the tank to carb on my 200, w/ a clear window on a inline fuel filter, so i can sorta see whats going on w/ the fuel anytime. if i was having ur problem, i could immeditaly cinch the little needle nose vise grips that lays there on the hose when it dies, then pull plug outa bottom of carb bowl, to see if any gas was in it

[123weld]

Could be loss off compression tho

Bolts headsteads could of loosened
No?

ive had that happen too. even had where bad intake valves on a flathead let compression blow by back into carb, and push fuel/bubbles back towards tank. i own alot of junk

[rexcormack]

A friend/coworker of mine had the same thing happen to his Farmall H.
Turned out it was a dead frog in the fuel tank!
It would drift around in the bottom of the fuel tank and occasionally cover up the outlet!
Now whenever something strange happens with equipment at work someone(usually me) hollers "must have a dead frog in it!"!

[RPM FABRICATION]

I am having the same exact issue. I cleaned out the carb and lines and it still turns off usually when welding unless I have the choke on and it eventually dies with the choke too. I was wondering if you found what the issue was?