plugged gas cap?

Thu Nov 28, 2013 12:38 am

So I ran the tractor out of gas the other day (oops), and it sat outside in the snow overnight until i could get more gas (double oops). I brushed it off, filled up the gas, and when i go to start it fires up and dies within seconds.. I happened to glance at the gas cap and there was a drop of water right over the vent hole, so i blew it off. Tried it again and she ran fine! Could that tiny drop of water really have caused it to starve or was it just a coincidence? I ask because sometimes I'll turn the fuel off to let it run itself out of gas if I'm not going to be starting it for a while, and it takes much longer than a couple of seconds to die...

Re: plugged gas cap?

Thu Nov 28, 2013 8:13 am

The water should be drawn into the vent as the gas goes down. It was most likely an air lock.

Rodney 8)

Re: plugged gas cap?

Thu Nov 28, 2013 9:29 am

I think it had more to do i running out of gas and you stirred up sediment when you refilled the tank, plus it had to pull gas back up to the engine. Anyhow glad you are back in business.

Re: plugged gas cap?

Thu Nov 28, 2013 10:58 am

Speaking gas caps... do you have an original cap or a replacement safety cap?

If not a safety one, TM Tractor has info and the link for the FREE one...

http://www.tmtractor.com/new/fl/fuelcap.htm

Glad you got it going,

Re: plugged gas cap?

Thu Nov 28, 2013 11:04 am

Eoghan wrote:.........when i go to start it fires up and dies within seconds.. .....................there was a drop of water right over the vent hole, ...
Definitely coincidence. If it died within seconds there is no way the Cub could of used enough gas to draw down the tank far enough to create a vacum in the tank. Half an hour or an hour maybe; depending on how full the tank is, the fuller it is the less air space and the sooner it could happen. With it running out the fill neck (really bad idea to be that full) it would still take many minutes not a few seconds.

Second thought, "a drop of water over the vent hole" does this mean you have the old style short cap with only one vent hole? If so I would suggest requesting your free tall baffled cap with multiple vent holes from Navistar and replacing it.

Third thought, your idea of the vent being blocked is very possible for a Cub that sits outside. Water can get in the vent holes. Water is not a big deal for the small amount were talking about it will get sucked on into the tank. What can create a problem is when water gets in the vent holes and then freezes. Ice makes a very good plug.