Is there some gas thats just too poor to run in a JD 70

I got the John Deere 70 gas out to work some this fall. Put it on a 61 foot auger and it ran just fine threw a few thousand bushels of corn. Drove it to the gas tank and partially filled it up with gas that was just delivered. It did have ethanol in it. Just wondered if the new gas from the bulk truck might have been dumped in a close to empty storage tank absorbing the water at the bottom of the tank. Tractor began to run poorly and now won't even start. I have tore the carb down and there were no plugs - all passages are clear. Good spark at plugs. Automatic fuel shut off works just as it should. Maybe I should drain the gas and put in some fresh from town. Any ideas?

Take a sample of that gas to the dealer let them test it.

Sounds like you're assuming a cause-and-effect without any supporting evidence. If the gas was bad, you should have noticed crud or water in the carb or sediment bowl.

What happens if you give it a whiff of starting fluid?

drain out that gas put in 5 gals from another source simple fast method to determine if its the gas.

sure its not deisel?

Had a similar problem on "15" one of our Model 70s.

You might consider checking the fuel flow to the carburetor.

The fuel pipe from the fuel filter to the carburetor was blocked.

Had a similar problem on "Vernon" another one of our Model 70s.

You might consider checking the condenser.

Replaced the bad condenser and it started with no problem.

Hope this helps.

The new fuel delivery could have stirred up whatever was sitting on the bottom of your storage tank. It takes a few hours for that floating debris to settle out again.

This is the most likely cause, probably some water that condensed in the bottom of the tank got stirred up too. Never buy fuel if the truck is making a delivery to a gas station either.

Do you have good flow of gasoline to the carb?

I have had plugged screens/filters since there is some rust in my tractor tank - however I have not had an ethanol problem to date. To check for water/ethanol phase separation simply drain a quart or so of gasoline into a glass jar - let set a few minutes - the ethanol/water phase will form at the bottom if it is present. It takes a significant amount of water to cause the phase separation so it is not as likely as many people think.

I have used E-10 for about 15 years in the tractors - I don't worry about it any more.

I suspect the condenser ,, they sure can play games with a good running motor ,,. like the other poster asked ,,. You Do not have a diesel theredo ya ,,??. dummer things have happened

With the gas line taken off at the carburetor the tractor has great flow of gas when the starter is hit. So, the oil pressure fuel shut off is working as it should. Tractor had new points and condenser and had worked well a few hours after they were installed. I am going to drain the gas tank and put in some new gas and see what happens. As I mentioned before it has a good spark. This problem didn't happen all at once. I noticed the engine started to run poorly over a few hours of time. Thanks for all of the ideas.

Here is a link to water finding paste . Good product to keep around.
Untitled URL Link

Ah yep . Over the years you can not believe how many service calls i have been on for tractors not running right , hard to start or not run at all due to bad gas . In my area we have a ton of old gas powered tractors that are still in use each and every day on small farms by today's standards . Went out on one call a guy had and 800 sires Ford that we had done his usual twice a year tune up on and a week later the tractor would not start after he filled the tank with gas just delivered by his fuel supplier , this was in the fall when everybody was filling there home heating oil tanks . He had 250 gallon of gas delivered and now the tractor would not start after he filled it's tank . I pulled the new plugs and they were wet and black, so i installed new plugs and the tractor started a little slow but it did start . While we were talking i noticed that she was smoking black like a diesel with a light load on it . I checked the carb adjustment and it made not changes to speak of . We shut it down and tried to restart on a warm engine and NOPE it ain't happing the plugs were soaked again. I did not have another set of plugs on the truck so i cleaned the first set with either and a propane torch and got the tractor back up and running and on the trailer to take back to the shop. I was not playing with it out in his shed in twenty degree weather. He needed a tractor to haul manure and grind fed with so i let him have my one 706 gasser to use while i figured out what was wrong with his ford . My 706 had a little over a 1/4 tank of gas in it when i hauled it back down to him that evening and was running fine . The next day i got into his tractor and went thru the carb and a new set of plugs i found nothing wrong with the carb and still had a problem with starting i thought that maybe the coil might be a bit weak so i put a new coil on it and no help there . Then he shows up at the shop to let me know now my 706 will not start , What that tractor sets outside and it will start at -30 degrees every time . So back out in the cold and down to his place three miles from the shop and nope the 706 will not start , pulled the plugs out of it and they are wet and black. I saw and old coffee can setting there and grabed it and out to his fuel tank and i put about a 1/4 of a can of gas in it and said do you have a match ???? He went to the hose and brought out a hand full of kitchen matches . Well IF the gas was good then one match would have caused a small flash fire explosion , NAh that did not happen as the lit match fell into the socalled gas and went out . Took and old rag and dipped it into the socalled gas and lit the rag after holding the match to it for a couple seconds it lit and burned like diesel but it had the smell of gas . So we tried to lite the can and yes it did lite but it burned like a smudge pot. black smoke just billowing . The fuel supplier did not clean out the compartment and the hose reel . And this guy was not the only one the supplier did this to that fall as i had six other people call with the same problem . And there other problems with todays gas in old gas tractors. I myself like gas tractors but we are now having tomany problems related to gas while trying to work them and i have just about given up on dealing with it.

I have a 44 B JD with 2 tanks. Start on gas & switch to a mix of half gas & half #1 stove oil. Seems to be hard on carb. floats. They crack up & sink. Last one turned black & split. I hung some .243 brass in the bottom of the tank & they all turned green. Gas is E-10. I now drained the tank & will try a new mixture.

Why not test the more of the fuel path? You missed the carb screen and float. Open the plug on the bottom of the carb fuel bowl.

Here is my take on this since I drove fuel trucks. All fuel tankers and farm tank wagons if on fairly level ground will drain out completely. So if you had diesel in this compartment this time it was not a problem going to gasoline on next trip. Most farm tank wagons have five compartment. I would say when he got back to the bulkplant to reload he forget that he did not completely empty this one compartment that had diesel in it and fill it back up with gasoline. That's your biggest worry as a drive is keeping track of whats in each compartment. Each time you come in to reload you are dealt a new hand of five cards.