8N runs rough at higher rpm

Lake County Tractor · Sep 8, 2017

My 52 8N idles very well in the lowest throttle setting. When I drive it or throttle it up it sputters a bit. Any ideas on a fix or what to look at?

Bruce (VA) · Sep 8, 2017

Did you set the timing after you set the
point gap?
75 Tips

Lake County Tractor · Sep 8, 2017

I thought this might be a timing issue. That's what it sounds like. My dad replaced the points and gapped them so I'll have to ask him. But what is the process of setting the timing?

JMOR · Sep 9, 2017

(quoted from post at 22:08:24 09/08/17) My 52 8N idles very well in the lowest throttle setting. When I drive it or throttle it up it sputters a bit. Any ideas on a fix or what to look at?

hat is a 'sputter'? If 'sputter' is a mis-fire, well, I say look elsewhere, as I have never in all my years & various engines seen timing cause a mis-fire.

RM-MN · Sep 9, 2017

If the tractor ran reasonably well before the points were replaced and now does not, I'd be looking hard at the new points. It takes a hotter spark to fire properly at higher speeds than it does at idle. The new points may need cleaned, re-adjusted, or replaced.

R Geiger · Sep 9, 2017

(quoted from post at 04:48:20 09/09/17) If the tractor ran reasonably well before the points were replaced and now does not, I'd be looking hard at the new points. It takes a hotter spark to fire properly at higher speeds than it does at idle. The new points may need cleaned, re-adjusted, or replaced.

I would adjust the carb before I fooled around with timing.I have changed dozens of set of points and have never reset the timing. If you don't move the distributor the timing does not change.

Lake County Tractor · Sep 9, 2017

t
Thank you for your straight forward answer I appreciate that. I'll start by looking at the carb.

Dell (WA) · Sep 9, 2017

LCT.......the sputter is usually a miss-adjusted carbie. Learn how to adjust yer own carbie. Heres the drill. Set yer down-pointing mainjet to 2-turns and LEAVITT!!! Adjust yer side-pointing idlemix fer FASTEST idle NOT SMOOTHEST idle. Understand the difference??? It'll usually be about 1/8-1/4 turn. WARNING: the side-pointing idlemix is BASS-ACKWARDS, out fer lean, IN fer ENRICH.......HTH, Dell, yer self-appointed carbie-meister

R Geiger · Sep 9, 2017

(quoted from post at 12:21:45 09/09/17) LCT.......the sputter is usually a miss-adjusted carbie. Learn how to adjust yer own carbie. Heres the drill. Set yer down-pointing mainjet to 2-turns and LEAVITT!!! Adjust yer side-pointing idlemix fer FASTEST idle NOT SMOOTHEST idle. Understand the difference??? It'll usually be about 1/8-1/4 turn. WARNING: the side-pointing idlemix is BASS-ACKWARDS, out fer lean, IN fer ENRICH.......HTH, Dell, yer self-appointed carbie-meister

Every carb and every engine is a bit different, while they may all run at two turns out on the main jet, they will run better if the adjustment is fine turned. FO-4 has a good procedure to adjust it except it says to start at 1 turn out, I start at 2 1/2 turns out and adjust like the book says from there.

Tim PloughNman Daley RIP · Sep 10, 2017

The original Marvel-Schebler Model TSX-33 Carburetor was used on the 9N, 2N, and early Tractors. The early books all say to set the Main Jet and the Idle Air Mixture at 1-1/2 Turns outward initially. The MAIN JET 2-turns out method was instituted when the TSX-241 carb came out with Economizer Jet addition. TheTSX-33 carb settings also say to set to the float level at 9/32" (.281") but now say to set at 1/4". I set all mine to 1/4" and if there is a problem, has been only one occasion, I then reset to the 9/32 spec. I get carbs with the float set all over the place -some with one side OK the other side way off.

Tim Daley(MI)

Charner (MS) · Sep 11, 2017

Had a friend that had the same problem. We traced it to the distributor. Found the cam weights to be rusty and not functioning properly. Cleaned and oiled them and bingo, like a new motor.

Lake County Tractor · Sep 11, 2017

Interesting. Thanks for the info that's something to look at.

8N runs rough at higher rpm

Lake County Tractor

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Bruce (VA)

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JMOR

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RM-MN

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R Geiger

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Dell (WA)

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R Geiger

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Tim PloughNman Daley RIP

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Charner (MS)

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