Need info on D2 Zenith main jet

I got a new main jet from John Deere, not to long ago. Also the gasket set. Think all told it was around $30.



[quote="Neil"]Hi all,
D2 3J4086 has the Zenith TU-4C carb (Cat 5F3530) and I had a couple of questions:
- is there a specific screwdriver for the main jet. It has a large bore with the screwdriver slot on the top of the bore wall. Is there a screwdriver with a pilot that fits in the bore to properly locate the screwdriver tangs for positive engagement? If not, I'll grind a generic one up
- is the main jet still available, either through Cat or John Deere or a third party? I'd like new rather than second-hand

Thanks
Neil.[/quote]

Thanks, do you remember the JD part #s? Did you just ask for a "TU-4C main jet" or did you supply a part #? If you have that, I can look it up online.
Cheers,
Neil.

Have your John Deere dealer dig out the parts book for 720 and 730 diesel engines. If possible, have 'em burn you a copy of the pages for the cranking engine carb. Their part no. for the main jet is R 13004.

Do you have the part number for the 5F3530 carb jet? Better go by the part number, they are not all the same. If you post the part number I can get you the Zenith part number and you can go from there.

OK, found it:
It's a 5F7633 Cat # and a Zenith # C52-30-15 .

I just put a request into my JD parts guy for price and availability. I have to pull the jet to see what size it is. Seems like this is the sort of thing that could be turned down by a competent machinist e.g. someone that could machine to 1/10 of a thou? I'm guessing the #40 on it might mean 40 thou?
Cheers,
Neil.

Hi Neil,
the scan below is from a carby book and covers Zenith old and new carby jet size markings.
At The Dealer we had a carby tool kit with all sorts of weird tools in and one of them I recall was like you suggested as a possible non-slip jet screw driver.
Often a gentle tap on the jet with an appropriate sized flat end punch can loosen the jet by slightly squashing down the fiber washer under the jet flange.

Hope this helps.
Cheers,
Eddie B.