There"s two things that makes a tractor run or not run . It needs a good flow of gas & a good spark . Drop the plug at the bottom of the carb to see if you get a good steady flow . There"s usually 3 filters in the fuel system that could be plugged . Or the main shut off could be plugged by rust & dirt in the tank . If gas flow isn"t the culpret , check the spark . Someone else will jump in here & help more than I can . These are things I"ve learned on these sites , so i hope I helped out a little anyhow . God bless
Britcheflee
Well-known Member
At the risk of starting another tirade from some posters here you really need to give us a lot more information - when you say it will not start does it just churn away and not fire? Is it turning over at all? Was it running fine and then just suddenly decided not to start the next time you tried to fire it up? Is is 6 or 12 volt? Did the problem start when you put the new battery in? There is a lot more information you need to give us including the distrubutor type and so on. Unfortunately without all the clues you can give us we cannot deduce the cause of your poor tractors demise...even though there are many here who are as clever as Sherlock Holmes!
Lee
Ultradog MN
Well-known Member
- Location
- Twin Cities
No tirades here. You are correct.
Not enough info.
Not enough info.
Bruce (VA)
Well-known Member
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.
We also need to know if the engine is turniing over & not starting.
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.
If the engine turns over but does not start, check for spark & 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 bolt in the bottom of the carb is the way to do it. 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, so that's why you need to use a spark plug. Or, a store bought plug checker (on the left in the picture). 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.
50 Tips
We also need to know if the engine is turniing over & not starting.
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.
If the engine turns over but does not start, check for spark & 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 bolt in the bottom of the carb is the way to do it. 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, so that's why you need to use a spark plug. Or, a store bought plug checker (on the left in the picture). 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.
50 Tips
Bruce (VA)
Well-known Member
" At the risk of starting another tirade"
LMAO!
Lets see if our replies were 'sensitive' enough.
LMAO!
Lets see if our replies were 'sensitive' enough.
elmersooner
Member
most common, I wish it were that easy. is it turning over?
Bruce (VA)
Well-known Member
Remove the rubber insulator going to the thumb switch. W/ the tractor in neutral, ground the wire to the tranny case w/ a screwdriver. If it turns over, the thumb switch is bad.
If that doesn't work, jump the solenoid.
If that doesn't work, try jump starting it per tip # 43.
Pls post back w/ results or other questions.
We may not be 'sensitive', but we will help you get your tractor running!
50 Tips
If that doesn't work, jump the solenoid.
If that doesn't work, try jump starting it per tip # 43.
Pls post back w/ results or other questions.
We may not be 'sensitive', but we will help you get your tractor running!
50 Tips
otto berlin
New User
have you tried bypassing the ignition by going from the top of the coil with a wire to the hot side of the battery? If this works, your problem is most likely the resistor. good luck.
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