Engine problems.

[winton]

I've got a Case 310 (~1957) that has run and been cared for pretty well for many years. It currently runs very smoothly, but only for about 30 minutes, at which point it revs a few times and then konks out altogether. Attempts to restart it result in it running for a few seconds before it dies again. Letting it cool down for a few hours means I can run it for another 30 minutes or so before it dies.

Ignition system seems fine -- getting healthy sparks in all the right places. There seems to be compression, otherwise it wouldn't run at all. Carb was cleaned not too long ago.

Any suggestions?

Thanks.

 

[BillyP]

You have some kind of fuel flow problem.

 

[LeRoi]

If the fuel flow is gravity fed, check the vent on the gas tank or gas cap whichever it has. It sounds like you are pulling a vacuum in the tank and running out of fuel. After you let it sit for a while, the vacuum equals out and fuel flows again.
This only applies if it is gravity fed, if it has an electric pump, the pump could be getting hot and shutting down. If it has a mechanical pump, you could be getting vapor lock meaning that the fuel line is getting hot and vaporizing the fuel in the line and since the the pump will not pump air it the fuel has to cool down and return to liquid to flow again.
Hope this helps
Leroy

 

[winton]

Good suggestions. There's no fuel pump, and since I've taken the gas cap off a few times during the period when it won't start (to make sure I wasn't being stupid and hadn't just run out of gas) that should eliminate any vaccuum problem, right?

 

[JerryG]

winton,
I am guessing that this is a gas tractor. If it is, try a new condenser.

 

[Egon]

I'll go with an electrical problem too. Runs long enough to heat up and then requires cool down before starting.

I had a Briggs& Stratton 8 HP that used to do the same thing. It was a condensor as someone else has stated.

Egon

 

[Glenn9643]

I had a '57 Ford automobile that behaved similarly. It would crank cold and run until warm and die. Someone told me to replace the coil and that fixed the problem. That was the only time I ever saw the problem, so it must be rare.

 

[LeRoi]

Winton,
Taking the gas cap off would eliminate the vacuum problem. The surging a couple of times before it quits is a symptom of fuel flow problems. I am really not familiar with the fuel setup on your tractor, we had 9N Fords and a TO30 Ferguson. Does the tractor have a fuel filter/water separator with a clear bowl so you can see if gas is flowing? If so have you changed the fuel filter or cleaned the inlet screen on the filter/separator?

 

[jrepp]

Might be vapor lock? Check the routing of the fuel lines.

 

[Soundguy]

I agree.. sounds like a fuel delivery problem.. it is starving and leaning out.. gov kick it up a couple times then dies.. carb bowl being empty.. restarts in a few minutes and quickly starves again as it sucks carb bowl empty.. let set.. and carb and fuel line recharge.. and runs again as before.

Even if the carb is clean.. there may be an upsstream blockage.. or even vacume on the tank from a clogged tank vent..

Soundguy