52 8N WOULDN'T START

[OLD FORDS]

Hello all,I've got a 52 8N that has always started without fail, it started and ran rough 3 days ago and wouldn't start again, good spark, adequate fuel wouldn't fire off. Hit it with starting fluid this afternoon, started right up and started again and again. Any thoughts ?

 

[Ultradog MN]

Time to pull your distributer cap off and have a look at the points.

 

[Bruce (VA)]

" Hit it with starting fluid this afternoon, started right up and started again and again. Any thoughts ? "

Could be it was just one of those days. Slightly discharged battery giving you a weak spark, cold weather, etc, etc.

Next time it won't start, try troubleshooting to see if it's spark or fuel; the starting fluid is more volatile than gasoline (and it's already a vapor)so it will address both a weak spark & some fuel issues.

It takes three things for an engine to run: spark at the right time, compression, & fuel/air 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, a spark checker w/ an adjustable gap (* see below) 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 won't start, check for spark then fuel. First, 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, hook up your spark checker, turn the key on & crank the engine. If the spark jumps the 1/4? gap, you probably don?t have a spark problem. If it won?t jump the ?? 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

Next, 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.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 ?? 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 (in the picture) will work better than an old plug because it won?t shock the snot out of you like an old plug might!

Post back with results or more questions.



*If you don?t own a spark checker w/ an adjustable gap, buy one. In the meantime, an old spark plug w/ the gap opened to at least ?? will work. Ground it to a rust & paint free spot on the engine turn the key on & look for
75 Tips

 

[OLD FORDS]

Thanks for your help and input, I've had your "50 tips saved as one of my favorites for several years and will now update it to "75 tips". It was probably "one of those days" its very very rainy and damp here in upstate New York for the past week, I wasn't really satisfied with hitting it with starting fluid, I was more interested in why ? Thanks again, Old Fords

 

[Bruce (VA)]

Been like that here in VA. Pull the cap and check the points like UD said. Replace the cap gasket. Spray the cap and plug wires with WD 40. Lubricate the operator with Jack Daniels.
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[HCooke]

Had the same problem a couple of weeks ago. We had very high humidity with condensation on everything. Very reliable 8N (6 volt, front mount dist) would not start. Had spark and fuel. I tried to dry everthing with a blower. Still no start. Next day it was raining but condensation was gone and it started up immediately!