Carb size and Identification 1975 340 S/T


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Mike Horrigan
Posts: 8
Joined: Mon Mar 02, 2009 2:12 pm

Carb size and Identification 1975 340 S/T

Post by 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
Posts: 12
Joined: Fri Nov 21, 2008 8:26 pm
Location: New Brunswick canada

Post by 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
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Location: USA

Post by 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
Posts: 8
Joined: Mon Mar 02, 2009 2:12 pm

Carb Size 340 S/T

Post by 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
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Post by 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
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Joined: Mon Mar 02, 2009 2:12 pm

carbs cdi

Post by 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
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Post by 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
Posts: 8
Joined: Mon Mar 02, 2009 2:12 pm

Carbs rebuilt

Post by 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
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Location: USA
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Post by SHewelt »

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