300 died, can't think what to check next

Zachary Hoyt

Well-known Member
This morning I was plowing snow with the 300 when I ran out of gas(should have checked before I started). I put some gas in, it started right back up and ran fine for a couple of minutes and then died quite abruptly and would not fire at all. I checked the spark at the points and it looks good. I tried spraying a little ether down the air inlet while cranking and it still wouldn't fire at all. It is turning over plenty fast, the rotor turns when the engine turns and I am at a loss as to what to do next. I think I could have got something in the gas system from the bottom of the tank but I think if that was the problem it should have fired on the ether. The only other thing I have thought about is the cap and rotor, I don't know if one of them could have cracked or gone bad, but it seems odd that it would be right after I ran out of gas. Any advice will be much appreciated.
Zach
 
Check and clean carb and blow air back through lines. Must have something to do with running out of gas. Low fuel in tank with the cold than warm you had. I am sure there is condensation in the tank you may have some ice too. oldiron29
 
i have had engines that would not fire on ether and i believe it was because there was water in the gas; cannot prove this.
because you have fire at the points, does not mean that you have fire at the plugs. make sure of this. i had a coil wire that went bad.

maybe you can drain the gas tank and try again.
 
Sounds like dirt in the carb, The "NEW" Eiher we get around don"t light up as good as the old stuff, Put some gas in a oil can give her a shot or two in the crab, See if it will fire then. Let us know.
 
My bet is a fuel problem.

Take the breather hose off and squirt some gasoline in there. If it fires then it will confirm that it is indeed a fuel problem.

If it is like my farmall h which has a dirty tank that needs cleaned then you can remove the fuel line at the carb open the sediment valve and back flush the dirt back up into the tank with an air nozzle. Good idea to have the fill cap loose or off when you do this. Of course we are hoping that none of the dirt actually reached the carb.

When I ran my farmall h out of fuel this summer this was all I had to do to get it running again. Once cleaned the tractor will run for years this way as long as you do NOT run it out of fuel again.
 
Fueling from cans is one source of problems. My uncle was particular to use a brass screen funnel. He showed us one day that the brass would prevent water from getting through when gasoline was already flowing. It also trapped flakes of???, as they tried to get into the tank.
Ask yourself:
How old is this fuel?
What was in the can earlier?
Is it rusty inside?
Condensation in the can?

Is there residual flakes in the tank?
Will sufficient fuel flow from the sediment bowl when the glass is off of it?

Keep thinking!! Jim
 
I learned early - if I run my M out of fuel it won't run right for an hour or so. I have no idea why. The fuel tank is clean. It just works that way for some reason. I've taken off running to the fuel barrel more than once.

Take the carb off and go through it. Oh, and hold your tongue just right.
 
When you put "some" gas in it how much did you put in? When you ran out of gas you slowly used the last gas. Now when your put some gas in it you were really stirring up the bare bottom of the tank and whatever was there.
I make it a habit of gassing the old guys the day BEFORE I intend to use them and allow any stirred up stuff to settle out.
And it helps to always fill the top half of the tank :)
 
Fire at the points means nothing. In fact with a good condenser you will not see much sparking at the points. Do you have a good hot spark at the plugs that will jump a quarter inch or more? If it won't fire on ether, I would be checking spark.
 
Zach - Before you get in too deep with the carb and such, stick a timing light on the #1 cylinder and verify the ignition timing has not gone awry. Can happen should the cam gear suddenly fail, which then causes a "no start" situation like you now have.
 
Remove No1 sparkplug near the radiator and bring that piston to tdc on the compression stroke. Once you're at tdc remove the distributor cap and see where your rotor is pointing. It should be at the No1 plug tower. Hal
 
Thank you all for your help. I took the line off at the carb inlet and had good flow from the tank, pulled the little screen and the fitting out of the carb and there was a little blob of debris inside the cylinder of screen. I blew it away and put it back together and the tractor started right up and ran fine while I finished plowing. I need to re-think my diagnostic method, but I am glad it was so easy to fix.
Zach
 
Check that you have a good blue/white spark that will jump a 1/4 inch gap at ALL 4 plug wires. Also if your daring enough grab the distributor cap when your trying to start it. If you jump 10 foot doing that you have a cracked cap and that will cause a problem like you have. The 340 I have I had a problem sort of like that this summer. Rotor would turn but I found out it only spun when I looked at it but with the cap and rotor on it would not spin like it should and I found some teeth on the distributor drive gear where bad and it moved when it wanted to and not other times which threw it way out of time
 
Glad it was simple. As with my h; you and I just need to remember to not run em out of fuel again. When in doubt add some fuel.

All that debris in the bottom of the tank does not hurt a thing resting in the bottom of the tank, but sure does get pulled to bad places when you run em out of fuel.
 
Oh by the way - we want paid for all the help we provided. Instead of money, How about posting some action photos of the next snow plowing? (LOL)
 
I'm no mechanic by a long shot, but I added an in-line fuel filter to my 300, which helps with gunk and junk in the line.
 

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