Engine tuning issues need help

[Manco335]

I have a 3.5 B/S on a manco 335 frame.Got it all mounted up and went to start the engine and i had to end up priming it with a little gas.Got it all up and running but has a little bit of a stall just off idle so i thought it was maybe a little rich since it would puff a little bit of black smoke indicating a rich condintion so i leaned it out a bit and now it wont stay running unless its choked 3/4 of the way closed.

I reset the idle mixture to its previous condition and still have the same issues.So now im lost as to what to do.Just a week ago this motor was bolted down to the bench and ran like a champ since then ive installed a home made header and an open air filter element.

Anyone know of any thing i can do to get this motor running correctly again?

Thanks in advance sorry such a long thread.

 

[Russ2251]

it wont stay running unless its choked 3/4 of the way closed.

This indicates lean condition. Possibly jet is partially blocked. Doesn't take much to cause problems. Try backing out adjustment to further richen mixture (1/4 to 1/2 turn?) and restart. This should be enough to clear out jet.

 

[Kenny_McCormic]

This indicates lean condition. Possibly jet is partially blocked. Doesn't take much to cause problems. Try backing out adjustment to further richen mixture (1/4 to 1/2 turn?) and restart. This should be enough to clear out jet.

LOL not always, learned that the hard way a couple winters back with the genset. 10hp tec fired right on up but was surging I shrugged and turned out the screw. Surging again later in the day, turned it out some more NOT THINKING. Half hour later power quits. I walk outside to see that the genset is pouring black smoke and running at idle speed.

The mix screw had rattled out(along with whatever was blocking the jet), keep your carbs clean!

 

[Russ2251]

along with whatever was blocking the jet,

Exactly my point. I just don't walk away from it. I have purposely backed them completely out while running. Then I pulse hole with my finger. Provided debris is small enough, it will eventually be pulled through by manifold vacuum.
You will hear it when/if it clears.