Boiling Gasoline ?

When I park in the barn I close the gas valve, disconnect the +ve end of the battery and connect the solar cell charger. (I've had problems w/ flat batteries - especially in winter.)

Anyhow - tonight - I also opened the gas cap to check the level - and "Pshhhhh hh..." - there was a great release of pressure and inside I could see the gas "boiling". Is this normal? Seems downright dangerous to me!

Other info ... Outside temp is 85 - most of the mowing is done in 3rd gear - when I finish and park in barn there is some overflowing from the radiator.

So - is this normal ?
Thanks in advance
Angus

Gaspump, Dunk, Dean - Tank vent? What's that? Opps ... Guess i've got some homework to do. Quick google tells me that its near impossible to reach without lifting the hood - and that a new vented cap will do the trick. Question ... is it a special 8N size , or are gas tank holes a universal size - and my local NAPA store will fix me up?

Gaspump ... I'll clean the rad and btw there's no thermostat in the top hose.

Dean - Winter gas? Sounds like something that *they* can charge extra for. Pusher fan ? Like somebody put the fan blades on backwards - so it blows rather than sucks ? Never heard of that before (but that ain't saying too much). Why they do that?

Sean ... blow it out w/ compressed air ? Ah... can I use garden hose ? or are you saying that'll damage the fins ?

Gaspump ... Advance ... Ummm. I just recently gave it a total electrics make over ... points, coil, plugs, cables, etc..

Again - Thanks - a new gas cap is in order.

Angus

Actually I wish I was able to answer some of those questions!!

The vent is a hole kinda in a bubble in the top of the tank under the top of the hood.

I DO think a vented cap will help bunches, and you won't hear them new finagled talking Ford automobiles telling you there is a problem because you forgot to tighten yer gas cap.

I've never run a t'stat, but that may not be a good thing from the popular consensus.

Winter gas, got me?!?!?!

Pusher fan, yep, like a bulldozer, they do make em, and they do have em.

Yes you can blow the radiator out with your garden hose, just don't try it with yer pressure washer, you may screw up the fins at 2200+ lbs of pressure. You may also soak yer distributor and coil, and be back with a "it won't start scenario".

Well I DID enjoy that!!

But thanks - great suport for a newbie.

PS: ealier list advice about a bad ignition switch presenting as fuel starvation was right on the money.

Thanks again
Angus

These days it is not uncommon for gas to boil in the tank of tractors that have the fuel tank above the engine.

This was largly unheard of 20 or 25 years ago (in the midwest, at least) and is due mostly to the higher volatility of today's gas. Avoid gas with alcohol if possible and you will have less of a problem. Also, winter formula gas is more volatile and more of a problem in this respect.

The fact that you witnessed a rapid release of pressure when you opened the cap indicates that the tank vent is clogged. This is not uncommon on Ns.

You may want to replace your fuel cap with a vented one because excess pressure can split a tank seam or cause a leak at another weak spot. This can happen just from letting the tractor sit in the sun with a nearly full tank.

Finally, does your N have a pusher fan? If so, you will probably have more problems with boiling gas as there is less air moving above the engine.

Dean

They (at one time) gave vented caps out free, just cause of this.

Now you have to buy one.

But mostly, I think your problem is a plugged gas cap vent. Shouldn't release pressure like that when you open the tank. And alcohol in the fuel. And winter-blend fuel.

Replace the cap. If it runs OK and doesn't build pressure in the tank, I wouldn't worry any more 'bout it.