8N is hard to start, but runs great

[Walston]

My 2N runs great and starts very easy, seems like it is running before the second "verump". I did put electronic ignition in it, but it did the same with points when they were nice and clean.

My buddy has an 8N, older restoration and a trailer queen. He gets it out once a year and it is always a fight to get it started. So he asked me to put electronic ignition on it because he got tired of fighting the points. Both his 8N and my 2N are front mount distributors. Both are still 6V and other than the electronic ignition and plug wires, they are both all original design.

The 8N is still a real bugger to get started. Once started it runs great, smooth over the entire range of RPM, but hard to start. We pull started it and it fired right up and it will start with the battery / starter but takes a long time. The carb has been recently rebuilt and seems fine.

I wonder if the coil is weak? Any ideas why this thing is hard to start but runs great, great oil pressure.

Any Ideas why this thing is so stubborn to start?

This post was edited by Walston on 07/28/2021 at 04:16 am.

 

[showcrop]

Conventional wisdom says to solve problems and get it running properly before changing over to electronic ignition, otherwise if the problem doesn't disappear you just add another variable and the water just gets murkier. You could perhaps get more help if you were to state what tells you that the newly rebuilt carb "seems fine"

 

[JD in da UP]

6volts is needed to get a spark. If your battery is low and you are cranking slow there may not be enough voltage for spark until you stop cranking. You
have to realize this timing in your mind when cranking and choking..Does the 8n start easier when warmed up?

 

[BarnyardEngineering]

Hard to start, how? Describe the starting process.

Hard to start can mean a lot of things. Many tractors pop right away but will not stay running and require several attempts to get the fuel air mixture right so it will stay running. Others just crank and crank with no response.

Is he using the choke? Most gasoline tractors need at least some application of choke when starting cold. They are not fuel injected. Every tractor is a little different, and you have to figure out what your tractor wants to start first time each day.

Only running the tractor once a year doesn't help.

Did he confirm lack of spark before messing with the points previously, or did he just start sawing away on the points any time it would not start?

Get a fifth spark plug and pull one plug wire while trying to start the tractor. The tractor will fire and run on three, and you can observe the plug for weak spark as he is cranking the engine. 6V does not leave much power for a good spark with a dragging starter.

After confirming good spark while cranking, get a can of starting fluid and spray some in the intake while cranking. If it fires right away you have a fuel problem. Starting fluid is not all ether, will not hurt your engine, and will not make your engine "dependent" on it.

 

[Mike M]

Make sure the spark plug wires actually have wire in them. Not the carbon fiber type these are no good on 6 volt.

 

[mhb@ufe]

One problem I see quite often causing hard starting with rebuilt carburetors is they set the float level too low so it has a hard time picking up the fuel at cranking speed on a cold engine. When tow starting it the engine is turning faster.

Mark

 

[Dean]

Old gasoline.

Dean

 

[Bruce from Can.]

I agree with Dean. Because you said this tractor is a trailer Queen, it probably doesnt get fresh gasoline very often. Drain out the tank, and put 2 quarts of fresh gas in the tank, start it and run it for a few minutes, then come back tomorrow and see how it starts. New gas just looses its ability to fire off in a cold engine.

 

[Steve@Advance]

Anything 6v must have everything just right to start.

One of the biggest problems is too small battery cables. They need to be size 0 or 00, only available at truck and equipment supplies, not the auto supply. All connections need to be tight and paint free, including the mount surface behind the starter. Have the battery load tested just to see where it's at, even if it is not very old. Feel for warm connections between the battery and starter, anything heating up is a sign of a weak connection.

A dragging starter will also cause too much battery draw and there is nothing left for the ignition.

Use solid wire or spiral core resistor plug wires, not carbon string type.

Be sure the choke closes fully. If there is no gas dripping after a failed start, chances are it is not getting fuel up to the cylinders. Try hand choking, if that fires it look closely at the choke plate and the float level.

 

[old]

A weak starter can do that due to pulling to many ams so not getting a good spark

 

[GordoSD]

Try turning it over with the starter for just a couple rotations then let of the start switch
Will it start just as you quit cranking it? You get a little voltafe spike for that brief moment.
What size are your battery cables?

 

[Dean]

Bingo.

Rarely used, pull starts and runs fine but will not start with starter.

Almost always old gas.

Dean

 

[Den N Ms]

Walston, As Gordo asked ,what size are the battery cables? To start with make up a new set with 0 or even 00 (better) cables with copper ends and heavy battery ends soldiered on and heat shrunk .clean shinny connections on all connections and cable ends and posts on.A verified load tested good or new 6 volt battery.Next remove the starter bolts and put a 5/16 nut on one of them to hold the starter together.Then sand the starter pocket shinny with some 40 grit paper also the end frame drive end,both sides barrel ends and brush end plate. so the starter has a good ground through out.
This will make a world of difference in cranking speed and starter draw.This will allow faster cranking speed and more power to the coil for great starts.

 

[showcrop]

Six volt starters don't crank a motor very fast. If your is cranking the cables and their connections should be pretty far down your list.

 

[Walston]

Follow up:

Checked all wiring and connections. all are clean, same result.

New battery, no change.

Rebuilt the starter, helped a bit, but still quite hard to start.

Swapped out the front mount coil and that fixed it. Fires right up and runs like new.