GS400 - want to add performance carbs

[zuki926]

Got a 1978 GS400 with stock engine and 2-1 header. Would like to remove the stock CV carbs and put on a set of new flat slides or ? Does anyone make a bolt on kit ? Thanks !!

[geol]

The stock carbs deliver as much gas as the 450 can use. The performance carbs you are dreaming of will probably make the bike go a tad faster because your wallet will be so much lighter... honestly, unless you modify an engine where it requires more gas, performance carbs are not the way to make a 450 faster.

[tkent02]

Put on GS500 pistons and cylinders. Easier upgrade that will actually provide more power.

[Rensdw]

Put on GS500 pistons and cylinders. Easier upgrade that will actually provide more power.

I don't think you can do that, the GS400 crankshaft has a smaller diameter small-end.

[Guest]

what gains do you expect?
is it a 4 or 8 valve?

[Guest]

If the carb spacing is the same as the 450/500's, then get a set of GS500 carbs. I'm running 2001 model carbs on my 450 and not only do they respond/perform better but parts are easier to get and they are incredibly light in comparison to stock. You should be able to continue using the stock throttle tube and cable also... at least I can on the 450.

[Rensdw]

If the carb spacing is the same as the 450/500's, then get a set of GS500 carbs. I'm running 2001 model carbs on my 450 and not only do they respond/perform better but parts are easier to get and they are incredibly light in comparison to stock. You should be able to continue using the stock throttle tube and cable also... at least I can on the 450.

I think they are really to big, you'll kill the bottom end power for no or marginal top-end power.