'41 9N Refuses to Start

BDodge

New User
I just replaced my points, rebuilt my carb, replaced manifold gasket, replaced fuel shut off, cleaned tank and fixed wiring, and put shear pin on bush hog.

The tractor ran perfectly and I was able to cut a few rows with bush hog. Broke a bolt, replaced and cut today. The tractor made a loud pop! then quit. Now it won"t start.

Is that because I didn"t read the 75 tips which said not to get Tractor Supply points? Frustrated. Hard to mow grass when tractor will not stay running. Help from MO!
 
" Is that because I didn"t read the 75 tips which said not to get Tractor Supply points?"

Could be!

But don't guess. Check it out. It's either spark or fuel.

It is important for you to tell us if your tractor has a 6 volt or 12 volt electrical system. 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.

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 is a 12 volt system. I am not good with electronics or electrical. I do not think the system charges. I captured your schematics for 12v system and will recheck once again. It is raining now with tractor getting a bath! Took battery out to charge. I did check spark after I replaced points, and it was a strong spark. Haven't checked since it popped. Rain came.

Also, noticed when it last ran the rpm was low then with no help on my part it accelerated.
 
'don't think it charges'


?

quit thinking and start verifying.


1st. get her running.

follow bruce's advice.

check spark FIRST
 
anytime you have runtime issues. check spark 1st. it's easy, and cheap and fast. may not be the issue.. but once you rule it out.. then you canmove on to more invasive tests..e tc.

let us know what you find.

good luck
 
Sunday, check the spark and it is good. Started up and ran for an hour and lost power. Brought it to garage to replace battery terminals (was going to do anyway) and saw my coil wire, Part of insulation gone and wire grounded to tractor, replaced.

Started up and ran for a while and lost power again. I brought it to the shed, turned it off, shut gas off, and heard a hiss. Opened the battery/gas compartment. Looks like I have vapor lock. Took off the gas cap and heard a release of pressure.

I did buy a higher quality of points and will not buy points or sediment valve from TSC again. Will also buy a new gas cap.

Got a couple acres mowed. 10 more to go! haha.
 
(quoted from post at 10:30:57 09/30/13) Sunday, check the spark and it is good. Started up and ran for an hour and lost power. Brought it to garage to replace battery terminals (was going to do anyway) and saw my coil wire, Part of insulation gone and wire grounded to tractor, replaced.

Started up and ran for a while and lost power again. I brought it to the shed, turned it off, shut gas off, and heard a hiss. Opened the battery/gas compartment. Looks like I have vapor lock. Took off the gas cap and heard a release of pressure.

I did buy a higher quality of points and will not buy points or sediment valve from TSC again. Will also buy a new gas cap.

Got a couple acres mowed. 10 more to go! haha.
o to vapor lock, but tank does need to be vented. Get a vented cap.
 
I agree with jmor.. it was not vapor lock.. but DO get a vented cap.

you can even drill your old one and install a loose pop rivit in the hole. cheap.. easy..
 
I will get vented cap.

If not vapor lock, then what?

I have noticed when I increase throttle lately, it takes a while to increase speed. A good 5+ seconds. My only thought is rebuilding governor. But why would it work in the beginning and after a while loose power?
 
Your tank has a vent hole towrds the front where you can't see it. It's probably been plugged by dirt daubers or sumpin. Tank needs to be vented so air can displace the gas which has been used from the tank. If not a vaccume is created in the tank and you will get symptoms such as you had.
Just venting
Pike
 
why not vapor lock? why? because you don't have a fuel pump. vapor lock is fuel pump nomenclature.

takes a while to come to speed? i'd be looking at carb settings first. both extremely rich and way lean could cause this. does it pop any? or gurgle?
 

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