# Carb swap



## bobcat2 (Aug 15, 2019)

Hello all,

After some doing some research, I've learned I can use a Carter 16 carb on my HH120, but it requires modified linkages.

I guess I have a few questions about doing this.

How do I start with a homemade linkage as far as length?

What material do I use for a linkage?

Any special tools needed, like a Z bender?

Let's say I pick up a Carter 16 and start fresh, how do I go about doing this? I assume you set the new carb to factory settings if it didn't come that way. Perhaps get a measurement from a reference point on the block to the original linkage, bolt the new carb up and use your reference to judge the new linkage length. If everything pans out, I should be able to fine tune the carb from there using the adjustment screws and my tiny tach.

I'm sure it's not too difficult, but I'm one of those guys who likes to have somewhat of an idea before I rip into something I've never done before.

Thanks,
bobcat2


----------



## Bob Driver (Nov 1, 2017)

OK, I get the HH120 Tecumseh and that the OEM 631498 carb is NLA (no longer available) I'm stubbing my toe on what you're calling a "Carter 16". I assume you mean either a Walbro, or a Kohler. The Carter Carburetor Company went out of business in 1986 and to my knowledge never made small engine carburetors

You're probably looking at something new aftermarket that will fit the old K-series Kohler engines. Since the HH120 was 12HP, a replacement carb that fits a K301 (12HP) Kohler seems logical as far as venturi size and jetting goes.

Whenever I'm trying to replace a carb that is NLA like on a Tecumseh, Clinton, or Wisconsin, I'll take a look through the trusty *Kohler Carburetor Reference Guide*. _Manuals tab this forum>Lawn & Garden tractor Manuals>Page 5_. It will give you Kohler carb #'s used by engine model, the Walbro x-reference, and you can usually find jetting/adjustment information.

For tools and material.... A z-bender is going to really help. For material I use the inside strand of old choke or throttle cables.

As for building the linkage, your biggest problem is going to get the governor linkage the right length. If you're off by even a 1/4" going from the governor arm to the throttle arm, it will either idle to high, the engine won't reach full RPM, or the throttle control cable throw is off.

I usually start with the old linkage as a reference (if you have it). An old 50" choke cable will give you plenty of material to experiment with length, especially if the throttle arm on the carb and the governor arm have several setting holes. You already have the Tiny Tac to check your work.


----------



## Groo (Jan 17, 2020)

Probably some somewhat universal carb out there that might be easier to get to fit thanicely a completely different OEM carb.


----------



## Bob Driver (Nov 1, 2017)

The HH120 came with either a Series 1 Tecumseh carburetor, or a Walbro LME. Both are really tough to find aftermarket. The closest match is a Kohler that goes on a K321. They're readily available aftermarket on either E-bay, or Amazon and they work fine on a HH120


----------



## bobcat2 (Aug 15, 2019)

Sorry, I should've specified. A carter 16 was on Kohler K181's, due to jetting size differences, its an equivalent to the Walbro LME from the HH120, I did get this verified from www.isavetractors.com, he told me I'd have to build a linkage from scratch.

It's not a major issue at the moment, my carb is ok, but since the tractor is torn apart, I figured now would be the time to maybe fabricate a linkage or two for the future while I have full access to everything. I'll probably end up experimenting with a Chinese clone since they're dirt cheap($12), but then that plays into another factor of "is it the carb or the linkage?".

It'll probably be a while before I tackle this, but I'll update this thread if I get something figured out.


----------

