Tuning a Mikuni (Help!)75 340 Sno Twister


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

Tuning a Mikuni (Help!)75 340 Sno Twister

Post by Mike Horrigan »

Carbs just rebuilt

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?
Last edited by Mike Horrigan on Sun Mar 08, 2009 10:43 am, edited 1 time in total.
SnoTwister340
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Joined: Sun Dec 14, 2008 3:32 pm
Location: Alberta, Canada

Post by SnoTwister340 »

whats the sled? Sno Twister/Trail Twister??? 250/340/440?
merc-eric
Posts: 34
Joined: Thu Dec 02, 2004 5:56 pm
Location: USA

Post by merc-eric »

I need the same info for the low speed air screws for my 76 440 trail twister so hopefully we get an answer!
snow, natures original "white gold"
Mike Horrigan
Posts: 8
Joined: Mon Mar 02, 2009 2:12 pm

Post by Mike Horrigan »

1975 Sno Twister 340 with 34/rs carbs
Drivebelt

Post by Drivebelt »

Did you make sure to clean the pilot jets? Sometimes they get missed, and if plugged, will cause the idling problems. Initial setting for the air screws is 1 1/2 turns out. Make sure carb slides are moving in sync, turn idle screws in until they just touch the slides then turn 3 turns. Jet needle clip should be in the fourth slot from the top. Once the engine warms up you can adjust the air screws in or out to get the best idle.
Mike Horrigan
Posts: 8
Joined: Mon Mar 02, 2009 2:12 pm

Post by Mike Horrigan »

I did forget the pilot jets, plugged solid. Running quite good now.
Thanks for the help
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