8n troubles

medicrick007 · Sep 29, 2010

I bought a "48 with some carb trouble... at least that is what I was told. I figured fix the carb and fix the issue... well after rebuilding the carb... the govner... replacing plugs... replacing manifold gaskets... I left the key on and burnt up my points... so I replaced them along with the coil. So it is still having the original problem. The only way it will run is if you crank out the high throttle screw on the carb. Bench settings for the screw is around one turn out from bottom and I am around 4 to 5 turns... not much turn left before it falls out. At the point that it actually does start, there is absolutely no throttle control. The throttle lever does nothing but make the govner rattle... help, please...

Bob · Sep 29, 2010

It's hard to tell WHAT your problems are over the 'net!

The governor problem COULD be due to mis-adjusted linkage, internal governor problems, the carb butterfly and shaft mis-assembled, or the locations of the two rods swapped around at the governor.

The "have to open up the mixture screw" problem could be plugged passages in the carb, worn, swapped or missing jets, something wrong in the venturi area, or even a bad gasket.

Also, valve problems, a manifold gasket sealing problem or even a manifold with an internal defect can cause problems like that.

If you want the maximum number of "GURUS" to mull over your problems, post this on the "N"-specific Forum linked below:
N Forum

Geo-TH,In · Sep 29, 2010

The carb adjustments on my 1953 jubilee and 1950 IH C are backward from what you may think. Screwing the main jet out is leaning the carb down. Both of my tractors, the main jet is cranked all the way out and they run fine, plugs are a clean gray.

This is only a guess, could be many other things, gas level in the bowl is too high. Does the carb leak gas when tractor is not running? If it does it could be a float or needle issue.

LOL
George

Bob · Sep 29, 2010

Gas level too HIGH means main jet has to be opened more than normal?

WOW!

Kentb of SWMO · Sep 30, 2010

ONLY the idle mixture screw on SOME carbs works in reverse as the screw controls the idle AIR. An adjustable MAIN jet is always richened by screwing OUT. I would check for an extremely LOW float level.
On a FIXED jet carb., the higher the float level, the richer the fuel mixture. This is why the float level is SO IMPORTANT on a fix jet carb. On a carb with an adjustable high speed mixture, the float level can be off a little because you can compensate with the adjustment. If the float level is extremely low you can not. Also check your governor linkage to be sure it is opening the throttle plate when you tension the spring in the governor system.

Kent

8n troubles

medicrick007

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Bob

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Geo-TH,In

Well-known Member

Bob

Well-known Member

Kentb of SWMO

Well-known Member

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