to35 runs perfectly for 30 minutes then goes dead

Does anyone have any suggestions? I am not a seriously experienced mechanic. I may need to seek one. Do I have a Carb. problem?

Good luck and keep us all posted on your findings

BOB UK
England

BOB UK, Yes, the sediment bowl did have a filter bolt and new filter screen etc.

I replaced the coil on Friday. You guys talking about overheating got me thinking, so I checked the radiator. Full, coolant tested fine. The front of the radiator did have a good bit of chafe on it. (I SHOULD HAVE ALREADY CHECKED THAT!)
I cleaned the chafe, checked all fluid levels and cranked her up.
After about an hour of use, she still was purring like a kitten. However, it was EXTREMELY overcast and cool in comparision to the previous test days. I will run again at a later date when the sun is out. Maybe it is fixed. Could have been the coil or the chafe. Does not appear to be the fuel. We will see and I will keep you updated. Any other suggestions would be appreciated.

Thanks again

Had same problem few years ago....
It was the ignition switch Switch had bad contacts and heated then quit
after cool down it restarted and ran for 15-20 min and stop again.

Switch can be checked by bypassing the switch with a wire jumper.

HTH

Bart

Don't laugh but that question saved me $1000 on a MF 65 I purchased.

Seller wanted $4000, engine cranked and turnned good but would not start. Owner said I put gas in, but there must be rust in tank and the fuel system would have to be replaced. I said cost of carb, tank, lines, fliters and labor is at least $1000. Purchased for $3K.

Took it home, and with a flashlight examined the tank. Clean as a wistle, I see the gas they put in, about 1/2 gallon. The gas didn't even come up to the reserve inlet.

I put in 5 gallons and she started right up, and I haven't had a lick of trouble with the fuel system.

Of course to fill an empty tank all the way would cost around $1000 today.

Next, open the fuel valve wide open, get a good sized container (to catch the $3/gal gas)and unscrew the plug in the bottom of the carb. Fuel should pour continuously (like a cow peein' on a flat rock) out of the bottom of the carb for as long as the valve is open. If it doesn't, check the "secret" fuel filter in the fuel inlet elbow on the carb and work your way back to the tank to find out where the restriction is.

If your supply is OK, then replace the plug, start the tractor and run it til it dies and recheck the spark. If spark is now weak (orangey or yellowish scrawny spark). Check all the primary ignition connects (clean, bright, and tight)and if that doen't fix it, I'd suspect the coil.

The brass block that the fuel line attaches to has a screen filter the fits into the carb.

Remove the fuel line from the carb then with a wrench gently unscrew the brass block from the carb. A screen filter should be attached and pull out once this block is removed.

you can clean yourself, or if it needs to be replaced they are ~$2.90 at TSC.

Hope this helps

Jeff

I had just replaced the condenser about 2 months ago. I will check the coil. I"ve got a new spare that I will likely change just to rule it out for sure. The condenser may need replacing again as well.

I left the gas cap off during operation for one of those cycles to see if it made a difference and it still went dead. I did not note any suction when I took it off multiple times tring to see if it would effect the flow unless it ran for a long time and it was not reproducable. It happened maybe twice over the four days and it was working okay when that happened.

Also, this tractor has worked fine for the two years that I have had it with the same gas cap. Could the cap"s vent changed in any way that could have caused this??

THe tank is a gravity fed system. As such, any fuel removed (i.e. used) needs to be replaced with air, else you start to form a vacuum. After about 30 min. The fuel supply stops and the engine quits. Most of the time there is not a complete bloackage, thus the girrgling/hissing sound. (unless your fuel is boiling) The sound is the air getting back into the tank. The fuel starts to flow again and it starts in about 2 minutes. But as the tank did not fully equalize with the ambiant pressure it happens again in short order.

Yes the cap vent can change. A piece of chafe gets in the hole and blockes it. Look at your cap and verify that the vent is clean and clear.

The one disturbing thing is you said you took the cap off and it still vent dead... Thus theory two.

Take a strong flash light and look through the gass fill hole and examine the inside of your tank. Is it clean? Is it rusty? are there bits of stuff in it?

As you changed the fuel filter and it worked for a while... the new one could be clogged now.

Also, did you change the fuel filter in the carb elbow?

just some thoughts Jeff