Gas line issue or gas tank?

wparris

New User
I have been rebuilding our 8n. The issue I keep having is that we have a rubber gas line instead of the solid gas line. Carb. is brand new. also the sediment bowl. When we start it will run for about 2 minutes and then it seems as if it is starving for gas and stalls out.
The other thing is that the top flip up lid hinge has rubbed a hole in the top of the gas tank.

Is it stalling out due to the gas tank having a hole in it, and/or could the rubber gas line constricting and limiting the gas flow?

I have put a lot of time and money into this beast and can not get it to run long enough to use it. Very frustrated.
 
First, check out tip # 15.

" Is it stalling out due to the gas tank having a hole in it,"

No. The tank is supposed to have a hole in it; it's a gravity fed system. No hole & it will vacuum lock.

" could the rubber gas line constricting and limiting the gas flow" Probably not.


" it seems as if it is starving for gas and stalls out. "

Find out why. Do not assume it's fuel. It might be.....but it could be spark.

It is important for you to tell us if your tractor has a 6 volt or 12 volt electrical system & if the distributor is on the front of the engine or on the side. The troubleshooting is different based upon the configuration of your engine.

It takes three things for an engine to run: spark at the right time, compression, & fuel in the right mixture. For the moment, forget about compression & concentrate on narrowing the problem down to spark or fuel.

There are three very important tools you always need to have in your N tool box: a 3 inch piece of wire w/ alligator clips on each end, an old spark plug w/ the gap opened to at least 3/16” ( ¼” is better) and a 7/16 box end wrench. (see tip # 50 at the link below) And, you really do need a working ammeter on the tractor; it is a very important diagnostic tool. With these tools, you can quickly narrow down most N problems to spark or fuel.

Next time it stops, check quickly for fuel then spark. When I say quickly, I mean get off the seat, grab the tools & do it right then. Do not wait a minute or two. First, check for fuel. Get a can & put it under the carb. Remove the bolt in the bottom of the carb; as long as the fuel is turned on, you should see gas flowing out of the carb. Let it run for at least 30 seconds. If it’s a dribble, or runs for 5 seconds & stops, or none at all, you have solved half the problem: it’s fuel related. If gas flows well out of the carb & only stops when you turn it off at the sediment bowl, chances are very good it’s not a fuel problem. So, next, turn the key on, crank the engine & look at the ammeter. What is the needle doing? Does it show a constant discharge, no movement at all, or does it move back & forth slightly? Next, get the old plug, ground it to a rust & paint free spot on the engine, turn the key on & crank the engine. If the spark jumps the 3/16” gap, you probably don’t have a spark problem. If it won’t jump the 3/16” gap, you have a spark problem. If the ammeter needle shows a constant discharge, or doesn’t move at all, that also tells you that you have a spark problem. Jump the ignition switch w/ your jumper wire & see what happens. If it runs, you found the problem. If it doesn’t have spark after you jump the ignition switch, post back for more info on further troubleshooting. (and do not forget to turn the ignition switch off; see tip # 38)

If it does not have gas coming out of the carb at a steady stream w/ the bolt out for at least 30 seconds, you have a fuel problem. First, remove the gas cap. Your vent could be clogged & it vacuum locked. If that doesn’t work, tap the carb bowl w/ a hammer handle in case the float is sticking closed. (don’t whack it w/ the head of the hammer; you can crack the bowl). If you still don’t see gas flowing, the N has three fuel screens; one in the brass elbow, one in the top of the sediment bowl & one on the stem of the sediment bowl in the gas tank. Check the screen in the elbow & the screen in the top of the sediment bowl. (don’t worry about the one in the tank) Both probably need to be cleaned. If you have the fuel knob turned on all the way, & 1 gallon or less in the tank, it may be trying to feed off of the reserve inlet which is probably clogged. Only open it 2 full turns. Put at least 2 gallons in the tank. (and do not forget to turn the gas off; see tip # 9)

There are ways to check for spark & fuel that work & ways that don't. For example, having gas to the carb is nice, but having it past the float is what counts! That’s why removing the 7/16” bolt in the bottom of the carb is the way to check for fuel. And, same thing w/ spark at the plugs. Some folks think that checking for spark means pulling a plug wire off & looking for one. Well, it's the distance the spark jumps at the plug that gives you the info you want. It takes about 17kv to jump a 3/16" gap & 22kv to jump ¼” in the open air. Remember, it’s 14psi outside of the engine & about 90psi at a 6:1 compression ratio in the cylinders & compressed air creates electrical resistance, so you really need the 17-22kv to fire the plugs when the engine is running. A store bought plug checker will work better than an old plug because it won’t shock the snot out of you like an old plug might!
75 Tips
 

It has been upgraded to the 12volt system. The coil and distributor are mounted on the front of the engine

As I am reading your reply I may be opening the valve on the sediment bowl to the reserve. Instead of only turning it 2 turns to "on". Thank you for the response Good info.
 
wparris, I'm no tractor expert, but if indeed the gas tank has a extra hole in it from wear, who knows how much debris is in the tank at this point. Also, as many others have posted here before, do not install an 'in-line' aftermarket fuel filter as they can reduce fuel flow to carb. Best of Luck, Old Fossil
 
Sooner or later the rubber gas line will swell up, get loose and burn up the tractor.Alcohol gas hardened the soft line on my tiller.Line dropped off the gas filter.Caught it while putting gas in the tank.There has been a post about a 9N burning up on here.As for the hole in the top of the tank, some epoxy putty made for sealing gas leaks will fix that.A gravity fuel system has to have an air vent and cars with a fuel pump need an air vent.New cars and trucks are different but that dosent affect a 9N.I have replaced many feet of cracked and mushy rubber line on rider mowers.While its called rubber it a different material.Rubber turns to mush in gasoline.
 
The rubber line while it can work is not a good idea due to what most use a tractor for. I simple brake line with the correct ends is the better way to go and can be bent to work just fine and I have done many tractors that way and it works better then the rubber line will. The 2 minute run time is maybe a bad ignition switch. I would try hot wring it and see what happens. If it runs then you know the problem is in the ignition system from the coil back. If it does not run then the fuel so pull the drain plug and make sure you have a good steady flow of gas for say 5 minutes. Catch the gas to look for dirt water etc.
 

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Back
Top