SC carb rebuild

[PaulFH]

Am rebuilding the carb off my SC again; a Zenith 9667. I installed the needle and seat that came with the kit. The new needle is longer that the old one. With the new one installed, it makes the float ride much lower(farther away from the casting) so much so that it barely has any travel between the needle and the stop. I compared the needles from two different kits and they are both this same way. Is it likely to have to shorten the new needle when rebuilding this model carb? I tried this the first time around without much luck.

Thanks,

Paul in MN

 

[Wilson]

Motec engeering tipton ind best carb rebuild I know of

 

[Anonymous-0]

You are probably not going to get enough gas in the carburetor bowl at a high enough level to make it run right. I guess you could bend the arms on the floats to raise the floats, if you can't find another needle.

 

[PaulFH]

I could try to adjust the float to the correct height but at best it's going to look like a pretzel. I'm really curious to see if anyone else has run into this situation with rebuilding a 9667. I have two of these carbs, that are apparently quite different in year, that have the same problem using the needle and seat that are provided in two different carb kits.

 

[PaulFH]

Here are a couple photos about what I'm seeing:

The first is of the three needles, original on left, replacement in center with mushroom head, and modified on the right. Has anyone else had to have done this too??

The second is of the float assembled. As you can see, the replacement needle with the mushroom head pushes the float almost all the way to the stop.

 

[messy gearhead]

Are you sure the float is not updside down? It seems like if it were flipped over it might line up correctly.

 

[PaulFH]

Thanks for the responses.

Yesterday I decided to go ahead and try putting it together with the modified needle. I modified it by cutting the mushroom head off with a small rotary disc and then rounding-over and polishing the pin end where it contacts the float arm.

With this change, the length of the new needle matches that of the original one. The tractor runs quite well now, so my problem with the carb must have been a slight blockage and/or incorrect float height. Feels good!

The mystery of the replacement needle length will go unsolved, I suppose, which is OK. BTW, the parts in question where from two different kits sold by Tisco: basic kit BK52V and complete kit C552V. These needles matched that in another kit that my local parts store has too. I don't have the name of the other manufacturer. It would be interesting to compare with the kit that Wilson suggested.

 

[Allan from PA]

Paul, I had the same problem. It took me a while to notice that the needles were different. I had bought a new float, so I thought that was causing the problem. After realizing what the problem was I used all the new parts in the rebuild kit except for the needle. I used the old one and the tractor runs very good.

 

[PaulFH]

Thanks for the confirmation Allan. Hopefully, others will benefit from knowing this too.