Fine tuning

[Tim Bozeman]

Well thanks to the help on this board, I've got the 9n running good. the only things I see that may be a problem are that the exhaust is a bit white(rich?) and when the engine is not under load(like going down hill) it misses ever so slightly. Are ethier of those cause for alarm?

 

[JMOR]

white=lean
black=rich
lean may be cause of popping while no load, but no alarm!

 

[Tom N MS]

Does it take the gas good when you fan the gas to it fast? If so, I"d leave it alone. If it stumbles, turn the main adj. needle out about 1/4 to 1/2 turn and see if it will take the gas fast..

 

[JjEjFjF]

Hello all. I dont meen to intrude. I was kinda of surprised to see someone having the same issue that i am having. I have searched high and low for answers with no luck. Like Tim my 9n stumbles quite a bit when under no load, even sitting still at idle. It will run really smooth for the first couple minute after a cold start then the stumbling begins. Again.....im sorry for butting in. I didnt see much sense in starting a new post on the same issue.

 

[Dell (WA)]

JjEjFjF......uh? you write......"It will run really smooth for the first couple minute after a cold start then the stumbling begins"......this is almost "classic" weaksister ignition switch problem. About 15-mins after starting, you gitt weak sparkies and stumblin'. BAD ignition switch ($10, cheap) .......Dell, yer self-appointed sparkie-meister

 

[JjEjFjF]

Thanks Dell. I wish it was that easy. I bypassed the ignition switch and still had the stumble. Also....i used one of those devices to check spark. With every plug wire i was able to jump a 1/4 in gap like a bolt of lightening.
Any other advice would be much appreciated.

 

[Jerry/MT]

Your sparks sounds good so check the carb mixture settings. Screw in the idle mixture screw in an eighth of a turn at a time to enrich the mixture and see if that helps at idle.

There is always the possibility that you have an airleak downstream of the carb metering section leaning your mixture. Leaky throttle shaft, gasket leak at carb/manifold interface, crack or hole in the intake manifold or a leaky manifold gasketre theusual culprits.

As far as the white smoke is concerned, that could be water vapor. Are you loosing any coolant?

 

[JjEjFjF]

Thanks Jerry/MT, Like so many other N owners that i know.....the idle mixture screw has to be turned in all the way to get a half decent idle.
Air leaks......carb just rebuilt, new carb to manifold gasket . New manifold and gasket. i know just because all of these things are new does not meen they are without imperfections. I tried all of the leak detection processes that i have read about like the WD40 and starting fluid. As far as i can tell there are no leaks. Im willing to tear the carb apart , remove the manifold and whatever it takes to try and solve this.

About the smoke. I guess i shouldnt have said i was having ALL the issues the original poster mentioned.

 

[Dunk]

(quoted from post at 21:29:01 09/23/09)
Thanks Jerry/MT, Like so many other N owners that i know.....the idle mixture screw has to be turned in all the way to get a half decent idle.
Air leaks......carb just rebuilt, new carb to manifold gasket . New manifold and gasket. i know just because all of these things are new does not meen they are without imperfections. I tried all of the leak detection processes that i have read about like the WD40 and starting fluid. As far as i can tell there are no leaks. Im willing to tear the carb apart , remove the manifold and whatever it takes to try and solve this.

About the smoke. I guess i shouldnt have said i was having ALL the issues the original poster mentioned.

It really irks me for someone to say they have a rebuilt carb, but I am going to try to be benign in my post.

What most M/S carbs need is a through cleaning, not a [b:bcc8568590]rebuilding[/b:bcc8568590] as [b:bcc8568590]voiced[/b:bcc8568590] by most, even fairly good mechanics.

Here is a recent post by Gary, he is one of the few, the proud, that knows what I am talking about.

http://ytforums.ytmag.com/viewtopic.php?t=530090

 

[JjEjFjF]

Thanks Dunk. I read that post a few days ago.
I cleaned the carb the best i could (meaning every passage was open as far as i could tell). When i mentioned about rebuilding i was referring to Jerry/MT's comment about an "air leak at the throttle shaft". At the time of cleaning i checked the shaft for wear (play) which there was very little of. I then installed the new shaft and seal.
Your comments make me wonder what kind of person would rebuild (replace seals and parts etc.) without doing a good cleaning first.

 

[Dunk]

(quoted from post at 22:07:04 09/23/09) Thanks Dunk. I read that post a few days ago.
I cleaned the carb the best i could (meaning every passage was open as far as i could tell). When i mentioned about rebuilding i was referring to Jerry/MT's comment about an "air leak at the throttle shaft". At the time of cleaning i checked the shaft for wear (play) which there was very little of. I then installed the new shaft and seal.
Your comments make me wonder what kind of person would rebuild (replace seals and parts etc.) without doing a good cleaning first.

One of the best ways I know of to know that you have the passages all open, is an air compressor, and a rubber tipped blow gun for it.

The rubber tip will seal around the openings.

And make sure that you can blow thru every hole and orifice in it, and that you can feel the air blowing out the places that it should.

 

[JjEjFjF]

Thanks Dunk. Lets suppose i take the carb apart again and do another cleaning and infact get the idle screw issue straightened away. Do you think that will solve the "studdering under no load" issue? After all , thats what this thread is all about.

 

[Dunk]

(quoted from post at 22:37:39 09/23/09)
Thanks Dunk. Lets suppose i take the carb apart again and do another cleaning and infact get the idle screw issue straightened away. Do you think that will solve the "studdering under no load" issue? After all , thats what this thread is all about.

I don't know....

The N tractors, in ALL their Glory.

Do have some idiosynchrosies in their idle, and back down, running that most folks seem to see as a problem, that ISN'T!

Ifn that N will sink a plow in the ground, deep, and pull it, and talk to ya, and not drop a lick....

And sit there and run at a very slow idle....

A problem may be all between yer ears.

 

[JjEjFjF]

(quoted from post at 18:51:08 09/23/09)

(quoted from post at 22:37:39 09/23/09)
Thanks Dunk. Lets suppose i take the carb apart again and do another cleaning and infact get the idle screw issue straightened away. Do you think that will solve the "studdering under no load" issue? After all , thats what this thread is all about.

Ifn that N will sink a plow in the ground, deep, and pull it, and talk to ya, and not drop a lick....

And sit there and run at a very slow idle....

A problem may be all between yer ears.

She does infact do all of that.
I will make note of your wisdom.
Always trying to pursue perfection is most definatly a curse.