Carb issues?

OHLowell

Member
Good morning everyone.

To start, 1946ish 2N/9N.

Over the past few weeks I have replaced a few parts on ye'ol tractor. (12V conversion, manifold, water pump, radiator) I finally got enough time in my schedule to finish putting everything back together over the weekend and now I have an issue.

I've got spark (verified with spark gap tester), I have fuel to the carb (verified by loosening the bottom bowl bolt to allow fuel to flow out of the carb.) The problem is that I can't get the blasted thing to start! When I started this project the tractor ran fine. Everything thing I did was more of a routine maintenance and 'make my life easier' type of improvements.

My typical procedure for starting the tractor is to choke the tractor all the way until it just starts to kick over, then go to half choke and it typically starts right up. I tried this and nothing..... it smelled like it was flooded. I pulled off the air intake line from the carb and gas poured out of the carb. I'll be honest I've never messed with the carb before and I'm not sure if this is normal or not but there is fuel leaking out of the air inlet to the carb when I try to start the tractor. I'm wondering if I didn't knock something loose while I was replacing the manifold.

Does anyone have any thoughts about this? I'll be honest working on the carb makes me nervous as typically carbs are not my forte.

Any help here would be greatly appreciated.

Thanks in advance.

Lowell in Ohio
 
Every tractor seems to have its own preferred starting procedure. That being said, you probably flooded the plugs with gasoline, so remove them, clean and replace. Try starting it without any choke for a couple of revolutions, if it doesn't start then add choke. My two 8N's, one a 12 volt conversion with EI starts almost always without choke, and a (new to me) 6 volt positive ground usually starts on the second rev with a quick pull of the choke. If it ran fine before your work, I'd try this simple thing before adjusting the metering screws on the carb. It is possible that your new manifold, and presumed new gasket, improved the vacuum and you might not need the degree of choke you did before.
 
"Does anyone have any thoughts about this?"

Yes.

Here is part of your problem: " My typical procedure for starting the tractor is to choke the tractor all the way until it just starts to kick over, then go to half choke "


First, replace the plugs. You flooded it, they're fouled & it will be it next to impossible to start. You don't need to toss them; heat the tips for a few seconds w/ a propane torch to burn off the invisible spark-robbing deposits from today's additive filled gasoline........or wash them in lacquer thinner or brake cleaner.

The usual cause of gas dripping out of the carb throat is operator error.

While each N has its own starting sequence, none of them will start well by just yanking out the choke rod & holding it out for 5 or 10 seconds while the engine cranks. This is a gravity fuel system on a low compression engine; it is easily flooded by too much choke.

Try this:

Key on, gas on 2 full turns, clutch in, 3/4 throttle, press the starter button. Let it crank for at least 3 - 4 seconds before you pull the choke rod. Then, don't hold it out for more than 2 or 3 seconds.

If you find out it will not start w/o excessive choking, you have problems.

Did you replace the points, set the gap correctly & set the timing when you did that 12v conversion?

Are you using the OEM ballast resistor and a 12 volt coil?
75 Tips
 
Thanks all for the input.

I had not thought about the plugs or the possibility of the new manifold needing less choke due to the better seal. The old manifold was shot on one end!

I'll give all of this a try when I get home and let you know how it works out!

Thanks

Lowell in Ohio
 

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