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differences in honda gx340 and 390 carburetors?

7119 Views 3 Replies 2 Participants Last post by  RED-85-Z51
Is the main jet (the one screwed into the bottom of the carb inside the float bowl) the only difference between 340 and 390 honda gx series carburetors? My 340 needs a new carb and i have a good 390 carb. Can i just switch the jet out and install it on the 340 or is there another difference?
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Ive run the 390 carb on 340's, 240's...haha

Bolt it up, see how it runs.
I did swap the jet and the little tube above it and put it on and it started right up and runs fine. :)
Yup...good stuff.

The 340 and 390 engines pare pretty similar.

As I know it, the carb is just slightly larger, the 390 cam has a little more duration and lift, the 390 has about 50 more cc's...for the most part, very similar. When I build a 340 up, I put in a 390 cam, carb...makes a decent little engine.
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