WooHoo!

She is purring like a kitten!

It was the float.  I bent/modfied it several more times.  I found a small piece of trash near the needle/seat entry (piece if a decayed gas line?)

Cleaned it.  REinstalled it, made a few adjustments and PRESTO!  

You guys are the greatest!

No backfiring.  Sweetest little idle you have ever heard!

Waldo.  You are correct, gravity feed, updraft carburetor.

I have a carb kit ordered.  New gaskets, needle, seat, etc.  It was supposed to arrive Friday, I am expecting a call today confirming the delivery to the tractor dealer.

Do you think a lack of fuel (ie. stuck closed float) would cause the tractor to backfire into the carb?  

I am beginning to wonder if this is not some other problem.  The tractor would not be running low on gas in the carb within only one-two revolutions.  Maybe this is a stuck intake valve?

TIA

TRG

you got a zenith or marvel-schebler carb?

i had the same problem with a zenith...esp. when the tractor was running uphill and tilted to the right.

i traced my problem to the float. it was starving the engine of fuel...a situation i could remedy from the seat by partially pulling on the choke lever (thus, making the mixrure more rich).

disassemble the float bowl and bend the stop tab on the float that opens and closes the fuel needle valve. just eyeball it and bend it so that the needle is closed with the float approximately level. bend it it the direction that allows the needle to open at a higher float level.

if you find your carb's air intake tube filling with gas...you went too far.

if you need the number of the best source of olt time tractor carb parts in north america, im me.

Campy,

"i had the same problem with a zenith.."  You mean yours was backfiring, or just starving for gas or both?

I will try rebending my float.  It would make sense that the float is somehow related to the backfiring since the tractor was NOT backfiring until the last float adjustment.

Thanks guys,  time to go disassemble that carb for the 4000th time...  [:(]

Thank you both for your help.

TheRedGoat