makita 6421 carb replacement

[makguy]

Just pick up a Walbro HD 12 from a Husky 372. Better carb and bigger to boot. You can pick one up on the Fee site for a little more than a 2 carb kits if you are patient. I've got an HD12 on all 4 (1-6401/7900, 2-6401 BBK, 1-Solo 665/681) of mine.
Shep

I'm curious to see how that carb looks in the saw. What mods did you have to do? Can you post pics of the finished install?

 

[w8ye]

The mods are all mentioned in this thread.

It amounted to brazing up the hole in the HD-12 choke lever and re-drilling it to the size of the original Zama carb.

Then it is a bolt on swap. The throttle arms are the same and the fuel and impulse line are in almost the same place on the carb.

 

[remduck1]

Found that the carb H screw was a double d adjustment. I used a thin cutting wheel in the die grinder and made it adjustable. Put it back together and tuned it to try it out while I wait for my BB kit to arrive. I must say that it does run and cut well stock but 20cc for $115 is just to tempting.

 

[TreePointer]

Congrats on the carb mod. solution.

You'll have a big grin after installing the BB kit. :chainsawguy:

Anybody know if those third party unlimited coils are available yet?

 

[remduck1]

will all of the plastics of the 6421 fit the BB kit? I have searched and read some old threads that talked about different air dams and top covers.

 

[makguy]

will all of the plastics of the 6421 fit the BB kit? I have searched and read some old threads that talked about different air dams and top covers.

Once again it depends on the generation of the saw because of the location of the decompression valve. The BB kit I got from Baileys fit great under the gray hood on the early version of the saw. The current black hood with the relocated decompression valve may not fit right. But I think the old hood is still available if you need it.

 

[Brewmaster]

I am not a big fan of a Zama. If I did have to change a carb on a 6421 it would not be with another Zama. I would use a Walbro off of a Husky 372. Its a direct bolt on except for the choke lever hole in the carb linkage. The dolmar uses a smaller diameter choke lever then the Husky. Just weld or braze the hole and re-drill it.

Later
Dan

Do the adjustment screws also line up when you use a Walbro HD-6B HD-12B in place of the original carb?