All that and it still requires choking

Problem: Won’t run without ¾ or more choke. It doesn’t like to start (but will sometimes) without a jumper from the battery to the coil.

What I have done thus far: Rebuilt carb (twice), checked fuel line for clear
What I have replaced: coil, points, condenser, cap, rotor, plugs, sediment bulb and valve.

The motor turns over without hesitation, so I don’t expect the battery to be the problem. However, I am going to put a different one in tonight and see if it helps.

This is a 1949 8n, front mount distributor, stock 6 volt system.

What do I try now?

I wound up taking the tractor to a full time mechanic. I needed to get it to run. My diagnostic skills are shallow and I was ready to replace the carb all together. I just couldn't believe that the carb didn't work....

Well....It didn't. They wound up taking the carb apart and tinckering with it to no avail...and at no charge. They put in a remanufactured carb and it runs like a top. Put it on the dino under load and she purrs.

So....The end result sometimes is to replace the carb. Hard to believe.

Preston.

Well, old, you got at least part of it right I'm sure. I discovered that the ignition switch, when giggled, was intermittent. So I jumped it at the contacts. This imporved things a little. I tested the battery and with no load it is at 6.50 volts, and 6.01 volts while cranking the starter. I took the new coil off and put back on the old one. This made no change. I'll return the new one as it was of no use.

It seemed that if I let it set for about a minute, and then hit the starter, it would run a short burst, then die out. This sure seems to me to be a fuel problem. I realy don't want to take the carb apart again, but it looks like I'm going to have to. As suggested by several, I will check the manifold for a vacume leak at the same time. I'll keep you updated.

P.

I tinkered with carb (rebuild kit etc...) and the manifold (new gasket, had old welded crack re-welded etc...) all to no avail.

I finally decided to get a new carb and a new manifold and, "eureka", problem solved.

I'm not sure if it was the new carb or the new manifold but it still runs great 26 years later.

HTH. Rick

I read you post about replacing your carb the other day. I thought about it again last night when I still couldn't fix the problem. I just hate to buy a new one when all the wear parts are replaceable, and should be cheaper then a new carb. I need to clean it at least one more time before I start to consider a new one.

Thanks. P.

And, you are right, the carb should not ware out and the replicable components can be replaced. But, they can get to the point where they just don't work properly, no matter what you do to them.

I don't think the original MS carb on the N is available new but rebuilt carbs are. You can try rebuilding again and take a small wire (torch tip cleaner, etc...) and poke all the small orifices and clean them out good.

A problem carburetor can be a real pain at times.

Good luck with it.

Best regards,

Rick

Check voltage at the coil with key on and points closed, should be about 3 votls or so.

The vacume leak test Dan told you about is pretty fool proof. I'll add.. that if you do the unlit propane test.. do it outside in the open.. it's fairly safe that way.. some use ether.. I think that's unsafe however!

Soundguy

Replace your manifold, put new gaskets in, clean up any pitting in the block with some high temp pucky or at least JB Weld (it will hold for awhile as it is on a water cooled block and protected from the worst heat by the gasket) if you are leaking in this area. This completely cured my 48 8N trailor queen that had the exact same choke issue to keep it running.

Good luck,
Dan