Carb size and Identification 1975 340 S/T

[Mike Horrigan]

What size carbs belongs on a 1975 Snotwister 340, and how do you tell what size they are?
What is the proper or best way to clean them? Is there a rebuild kit?

[twisted76]

carb is a Mikuni VM36-23. On the backside of the carb near wear it fits into the rubber boot it should be stamped 36 and under it 23

[Mercury]

Best way to clean them is to remove all rubber parts and to soak it overnight in Lacquer Thinner then blow it out with compressed air.

There is a gasket set for the carb bowl. Needle and Seat is also readily available.

Bill

[Mike Horrigan]

Sled one has 34 with RS underneath.
Sled two has 36 with 42 underneath.
Once I get them cleaned will they run with these carbs?
Sled two has a Sno Stuff cdi box is there a better box?

[SHewelt]

34RS is the original 36mm carb for the 75 340...should have a #320 main jets. Yes, there is a more reliable CDI available, but no point in changing it if the CDI is still working.

[Mike Horrigan]

Right now it will idle rough on only one cylinder, Its spits and backfires out of the other, I'm going to start with a carb rebuild, I just wanted to know what may be next. Where would I get a box if I need one?

[SHewelt]

Swap the carbs & see if the problem stays with the carb or the cyl...that will tell you if it's the spark or carburetor. If it moves to other cyl, spark is OK & carb is the problem. www.cdibox.com has CDI boxes for the MERC's with a good warranty

[Mike Horrigan]

Running on two cylinders at medium or high speed
Bogs on low speed
Will not idle without a little throttle applied
Mag side carb spitting fuel out of the overflow tubes.
How many turn should the idle and the low speed screws be set at initially?

[SHewelt]

Replace the FLOAT NEEDLE & SEAT on the carb...that is causing the overflow & rich condition...