SC--something missing on Carburetor

The part you are looking for is C71-21: Jet, Main Adjusting Assembly.

I bought two of them earlier this year from a Zenith distributor- V.E. Peterson. Their number is listed below:

I think these cost around $12 apiece for the "T" needle, needle body and packing. According to Zenith Fuel Systems- the jet (seat) itself is no longer available.

Dave Reed at Otto Gas Engine works has this assembly as well, but I don't think they are listed in his online catalog.

Hope this helps,

-Schotte

p.s. - from reading some of the rebuild instructions I've collected- it appears that certain models of the Zenith carbs DID have that port "plugged" and non-adjustable. Do you know if yours has been replaced? It should be a Zenith 9667A (05771AB)

• V.E. Petersen web site

Thanks for your reply and the info. Carb is 005771 AB (9667A). And in further review of the schematics of the carb kit I have on hand, it does show a plug-type as alternative to the adusting valve. So if the tractor is running rich, how can any adjustments be made without this valve adjustment is my question?

From the drawing it looks like the plug would be interchangeable with the valve and that the seat that's there would work with the needle type valve as well. Am I correct or was there a special seat that came with the plug type? So if I ordered a valve from V.E. Peterson I could just install it in the port, make the proper adjustments and...have a smooth-running tractor--if it were that simple. There may be some internal problems with the valves and have not done a compression test yet. Just adjusted the valve lash and it does run much better than it did--these clearances were way off. Valve cover had not been off for a long time and had a bad build-up of sludge. This tractor's care was neglected--about an inch of sludge in the oil pan too. If you have any further suggestions-would appreciate them.

Gerald

I don't have any of the rebuild kit instructions in front of me here at work- so I don't know about the plug type having a different main jet.

I can't imagine an application that wouldn't need an adjustable main jet... maybe some sort of power unit?

As you probably know, this jet is the "load screw"- so I don't know how you can get by without it. My tractor would idle fine, but would sputter and cough anytime it was under load until I got this set correctly.

The manuals say 1-1/2 to 2 turns out on the main jet adjustment before you do the fine tuning. Mine never worked like that. I get very little response from my idle adjustment screw- and my load screw has to be about 4-1/2 to 5 turns out to work correctly under load.

Of course with a "T" handle, what I'm considering a "turn" may only really be a 1/2 turn.

Good luck, and keep us posted.

-Schotte