Hi all,I have a problem with my 9n quitting after about an hour of hard work.It still has spark.I also pulled the plug on the bottom of the carb,and gas drained freely through.After it cools,it starts and runs normal.Any thoughts? thanks in advance,Stan
jinman
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If you are certain all plugs have spark, spray a little starting fluid around the air intake when the engine stops to see if it trys to start. I think your problem is vapor locking in the carb. Even though the float chamber has gas flowing into it, the fuel may not be atomizing properly because it is boiling. I would try cooling the lines and the carb with ice to see if that got things going again when it stops.
If it's not a vapor lock problem, it may be trash that is randomly plugging your needle valve on the input to the float chamber or main jet...most likely the main jet since the float chamber is getting fuel.
On these simple engines, there are just so many things that can keep them from running:
1. Choked...no air or too little air
2. Not enough fuel (vapor lock or trash)
3. Too much fuel (flooded)
4. No spark
5. Intake or exhaust valves sticking open and loss of compression.
If the first four are okay, then do a compression check to look for stuck valves.
If it's not a vapor lock problem, it may be trash that is randomly plugging your needle valve on the input to the float chamber or main jet...most likely the main jet since the float chamber is getting fuel.
On these simple engines, there are just so many things that can keep them from running:
1. Choked...no air or too little air
2. Not enough fuel (vapor lock or trash)
3. Too much fuel (flooded)
4. No spark
5. Intake or exhaust valves sticking open and loss of compression.
If the first four are okay, then do a compression check to look for stuck valves.
I had the same problem with my 9N. It's most likely vapor lock, I tried insulating the fuel line that runs over the engine with pipe wrap but that only gave me about 10 more minutes of run time. I would have to let the engine cool down a few hours before I could cut again and when I went away for the weekend to cut 20 acres I wasted the whole weekend. I was afraid to use the tractor to do chores in the woods because if it stalled I'd never get out. I got so fed up I traded it in and got a TC30. Now I cut in no time at all.
Soundguy
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See my post about this same subject in this same forum.
my bet is spark really isn't good.. but looks good in an air gap. these N are really.. really hard to vapor lock except under rare circumstances.
My bet is bad ignition coil due to improper votlage / ressitor matching.
The square front mount coils are not robust in any sense of the word. And they are not a true 6v coil.. they are more like a 3v coil.. etc.
Soundguy
Soundguy
my bet is spark really isn't good.. but looks good in an air gap. these N are really.. really hard to vapor lock except under rare circumstances.
My bet is bad ignition coil due to improper votlage / ressitor matching.
The square front mount coils are not robust in any sense of the word. And they are not a true 6v coil.. they are more like a 3v coil.. etc.
Soundguy
Soundguy
