8n very cold collared

[Graveyard1984]

My 8n starts good when the weather is warm
As long as you leave the throttle in
lowest position and using the choke.



If least bit cool out it will not start.

Is this normal for these tractors. Is it
a possibility a timing issue or what?



Tractor does have new plugs, new carb. It
has a slight miss while running also so
that is why I thought it might be a
possibility of the timing being off a
little bit


It is a later model with the side mount
distributor. I only run pure gas no
ethanol




Thanks

 

[Joe.S.AK]

84,

Without knowing much about your specific tractor, the "New Carb" sounds like you might have bought a brand new Chineeseium one --- and they can be dodgy at times. Did you tear down the new carb to see if there might be a bit of manufacturing junk inside it - say a jet partially clogged?

A little water in the float bowl?

Is the air intake path clear and is the filter clean and in good shape?

Cold shrinks things. Are there any air leaks in fuel line connections? [b:c7e9ced0a2]No[/b:c7e9ced0a2] aftermarket in-line fuel filter - right?

As a suggestion, pull a plug. You could have it running a bit too rich (((carbon build-up on the pulled plug gap?))) or possibly too lean (((Spotless plug gap))) .

Maybe re-reading the book and re-doing a new carb set-up and adjustment might be beneficial.

Any other suggestions from others - you know, like don't throw away that "old" carb because it could be the "new" rebuilt one in a week or two.

- Joe -

 

[Joe.S.AK]

84,

Without knowing much about your specific tractor, the "New Carb" sounds like you might have bought a brand new Chineeseium one --- and they can be dodgy at times. Did you tear down the new carb to see if there might be a bit of manufacturing junk inside it - say a jet partially clogged?

A little water in the float bowl?

Is the air intake path clear and is the filter clean and in good shape?

Cold shrinks things. Are there any air leaks in fuel line connections? [b:46aeb0237e]No[/b:46aeb0237e] aftermarket in-line fuel filter - right?

As a suggestion, pull a plug. You could have it running a bit too rich (((carbon build-up on the pulled plug gap?))) or possibly too lean (((Spotless plug gap))) .

Maybe re-reading the book and re-doing a new carb set-up and adjustment might be beneficial.

Any other suggestions from others - you know, like don't throw away that "old" carb because it could be the "new" rebuilt one in a week or two.

- Joe -

 

[Graveyard1984]

The carb was on it when I purchased it.
The carb is very bright and shiny.
No everything is factory.

 

[mhb@ufe]

Your symptoms may be an indication of the float level being set too low. With the throttle set low and full choke you are getting maximum vacuum so it will pull gas from the bowl. With the float set at the proper level it requires less vacuum to pull gas from the bowl.

Mark

 

[Bruce(VA)]

" The carb is very bright and shiny."

Likely a cheap Chinese clone.

Some folks can get them to work. Most don't.

Plenty of good OEM rebuilt M/S carbs out there.
75 Tips

 

[Dean]

Verify that ignition is spot on before looking elsewhere.

No, it is not likely a timing issue.

Low cranking speed and low compression are most likely causes of failure to start if ignition is spot on and engine is getting fuel.

Dean

 

[Btzj02]

Is this normal for these tractors.

The "normal" of my 8N51, side distributor like yours, requires 1/2 throttle and no choke in the summer. When it gets cold it requires 1/2 throttle and full choke to start but then about a quarter inch choke for a few minutes as the engine warms up.

 

[a32vickyhotrod]

(quoted from post at 07:41:14 01/22/21) Is this normal for these tractors.

The "normal" of my 8N51, side distributor like yours, requires 1/2 throttle and no choke in the summer. When it gets cold it requires 1/2 throttle and full choke to start but then about a quarter inch choke for a few minutes as the engine warms up.

Close to my 8N normal also.

Forget about timing. Once timing has been initially correctly set, it will not change enough to cause starting or running problems unless the point gap has been severely altered.

Correct timing along with correct centrifugal advance weights has more to do with attaining maximum horse power at operating speed.

 

[Jim in Western MI]

I think every tractor has its own preference to be started. My oldest 8N was been converted to EI many years ago, but it started fine before that unless the points were getting bad; when changed, it would start fine. IN warm weather, 1/4 throttle and no choke unless it had been sitting for a few weeks. Just a brief choke pull/push while cranking and off it went. When cold, 1/2 throttle and feathering the choke for a minute has it going great. I will mention that the carb adjustments screws have not been touched in over 20 years; they're not likely to change and if you start messing with them after it's run well, you really don't know where your problem might be, or if you have two problems that work in opposition to each other. The newer 8N had it's carb rebuilt by Royse as it didn't take throttle movement well; it was 6V for time but starts great. It's still on traditional points and in the Michigan cold needs only a quick pull/push of the choke and starts up fine even in the teens. I did convert to 12 volts just to have battery minders that did cars/trucks/boats/tractors. I don't think your tractor is right if it doesn't start when cool or cold; and I doubt any of the above helps you other than assuring you that it can be fixed and work properly when cold. By the way, I had a 601 for a time that wouldn't start and kicked my butt for several weeks. Then I found out about that little clip on the distributor shaft that I had never seen.

 

[Jim L WA]

How old is your battery? What is the voltage when you try to start the tractor? A weak battery will do just what you are describing.

 

[JerryCPP(WA)]

More years ago than I care to remember, and old Ford salesman told me how to start an 8N in cold weather. Fuel on; pull choke; turn engine 4 turns; push choke in; ignition switch on; start, and be ready with the choke. I've been using that method on my '50 8N ever since, and it will start every time down to about -20 degrees F. It's still 6 volt.

 

[lha]

I've actually driven vehicles,including a '48 Dodge truck to work 5-6 days a week in all different weather. They were 6v,+ground as most were until the '50s. I started using this system after a cold start attempt prompted an old Coot to help me get it started. He explained that the few revolutions with the key off,choke on full allows a fuel charge to get to the cylinders to make the motor start when the key is turned on. My 9n starts very easily every time when started like that. Many will argue that it doesn't work like that,but 50+ years of driving relics says different.

 

[rickdude]

I had similar issues with my 8N, pull off your intake boot and have a look in the carb at the choke plate. The OEM carb had a spring loaded flap window in the plate, mine was missing leaving a gaping hole which didn't choke anything. I fabricated a solid plate with a small window, the tractor now starts well, even down to -15 degrees C with no preheat.
https://forums.yesterdaystractors.com/viewtopic.php?t=1256977&highlight=

 

[TheOldHokie]

(quoted from post at 15:08:52 01/22/21) I had similar issues with my 8N, pull off your intake boot and have a look in the carb at the choke plate. The OEM carb had a spring loaded flap window in the plate, mine was missing leaving a gaping hole which didn't choke anything. I fabricated a solid plate with a small window, the tractor now starts well, even down to -15 degrees C with no preheat.
https://forums.yesterdaystractors.com/viewtopic.php?t=1256977&highlight=

I am going to bet you are the closest guy yet to identifying the actual problem. Maybe not the flapper but something in the choke....

TOH

 

[Tim PloughNman Daley]

A worn engine will be hard starting in cold especially so is it 6V or 12V? One reason to go to 12V is quicker starting on a worn engine. Check the battery first - have it tested at a shop, not just charged, get a Float Charger (Battery Tender) when non running. 2nd, verify wiring whatever system you have. Is it correct? How do you know? 99.98% of all non-starting issues are due to mucked up wiring. 3rd, what was wrong with OEM/old carb? All components meant to be rebuilt over and over. Buying most anything new these days means Made In Cheena (re: junk) so don't think you can just take it out of the box and install it and it will run. Did you disassemble and check it -float and settings? What is the oil pressure at start up and then after warmed up for a half hour? It's your tractor and your time and, especially, your money so you can do whatever you want but spending twice as much for "pure gas" is nonsense and a waste, IMHO, doesn't do anything except keep the big oil companies in business. Bruce(VA) has the best procedure for starting. Cranking and choke pulling to no avail means something seriously wrong. Spark test first, power to coil, fuel test 2nd, compression 3rd, and don't start replacing parts willy nilly. True root cause problem solving, not WAG's, is required.


Tim Daley(MI)

 

[Abbby]

I am in the similar situation as Graveyard1984. When warm throttle in lowest position and no choke it pops right off. Problem is when the weather starts getting cold. It will pop off at idle but not enough to keep it running so feel like I have to give it a little throttle first and then bang it is flooded. My engine is strong, blue spark jumps large gap in tester and tractor runs great. It was 12F this morning so I decided to try the crank it a little with choke on and key off. Historically there was no way the tractor would start. Well is did not start right away but I did get it going. I am going to go thru the carb when I get a chance to double check stuff. Until then I take my heat gun on the manifold for about 2 minutes and all is good.

 

[Graveyard1984]

It is a 12 volt system. It cranks over really good but will not hit. The carb was replaced previously before I purchased the 8n so I don't really have any clue why it was replaced.

 

[Graveyard1984]

I've checked the choke flap and choke rod every thing is working there.

 

[TheOldHokie]

(quoted from post at 01:09:43 01/24/21) I've checked the choke flap and choke rod every thing is working there.

Try placing your hand over the carb intake when cranking. Or give it a small squirt of raw fuel. If either of those gets it to fire you have a cold enrichment problem.

TOH

 

[soaked]

Hi Graveyard1984,
I'm just thinking out loud, and wonder if you, ( or anyone else ) has tried closing the idle mix screw, all the way?

Would be max rich, and max suction from the primary idle orifice, when starting from the lowest idle setting.

It would sacrifice some atomizing, for
raw fuel, maybe a desirable trade off when cold?

Would expect to open 1/2 turn or so, after running a few moments. May need a third hand to run the choke tho...

Up here in western wa, it seldom is very cold, but I frequently use the lowest throttle setting when warm out. The challenge is to wait long enough before raising rpm to warm up.