8N rough running while bush hogging

[Eric L]

1948 8N 6 volt front distributor.....I hooked up the bush hog and tried to mow today but i had to keep the choke all the way out in order for it to stay running under a load.I checked all the screens and it dont seem to be starving for fuel,i have a good stream coming out the bottom of the carb.I also took the carb. apart and it is clean.Dont know what to try next.

 

[Britcheflee]

Mine was doing a similar thing - turns out that it was poor spark and two gummed up spark plugs - pull the plugs and check for spark and that they are clean and properly gapped (as well as all electrical connections nice and clean and tight) - however, I am sure you are going to get better advice from the more knowledgeable members here.

BTW - I had to clean my carb twice before it was actually completely clean and all small passages completely clear.

Lee

 

[Eric L]

Well Lee i checked all the plugs for gap and they are all gapped at .025 ad all the conections too.It still running rough under load and i have to keep the choke out.

 

[dlplost]

points...

 

[Bruce (VA)]

Pulling out the choke gives you a richer mixture. So, you could have either a fuel or spark problem.

A carb out of adjustment will also cause this problem; have you been fooling w/ the main jet adjustment lately? Put it back at 1 1/2 turns out & leave it alone.

A dirty carb can cause the problem as well. It takes soaking in solvent & blowing out every orifice w/ compressed air to properly clean a carb. If you didn't do that, it probably needs it.

Dirty/old gas, or water in the gas can cause this problem.

Restricted fuel flow can cause this problem; sounds like you have ruled that out though.

On my 1950 frontmount, needing choke to run is the first sign that the points need adjusting/replacing. When is the last time you did that?

Old plug wires can cause the same problem.

And, finally, a vacuum leak can do the same thing. Get a hand propane torch and carefully spray it (unlit of course) around the intake manifold of the tractor while it is running. Or, you can use carb cleaner or WD40. If it speeds up, you found the leak.

Bottom line: by far, most "needs choke to run" problems a fuel related, but do not rule out ignition problems. Just check the likely fuel problems first.

Please be sure to post back & let us know what the fix was. We all learn something if you tell us what worked!
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