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Hi, I have a 1974 TNT 340 fan. I have almost finished restoring it and still cannot find the choke and throttle cable. So I am now going to convert it to a mikuni. I need to know what to look for. So i need the model of carb and all the setup specs. I know the first year they used mikuni carbs on my sled was in 1976 on the 340 fan. Right now I have a mikuni carb for a 1976 olympique but its a VM 30 and I think I need a VM34. Not sure?

Hope someone can help me out

Thanks
 

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Use the VM30 off the Olympic. In `76 Doo came out with a "kit" to change the 340 TnT FC to a Mikuni, it was a VM-34 carb. They produced the `77 340 Everest at the start of th year still with the Tilly HD carb, then part way through the year they went to the Mikuni, it was a VM30. Then also used the VM30 for `78/79. The `77 to 79 - 340 Everest is the same engine & pipe as the `74 - 340 FC TNT. So carb specs from the Everest ARE CORRECT for the `74 TNT

JET your 30 mm as:
Main Jet 250
Pilot jet 35
Needle jet 159 Q0
Jet needle 6F9-3 ( clip on third notch)
Throttle slide cut-away 3.5
Air screw 1.5 turns out.
Good luck
 

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just in case you want to use the vm34 let me kno as I have the specs.
 

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degasus,
Yes I would like to get the specs for the 1976 340 carb.
Thanks
Would going to a 240 or 230 jet in a 340 everest make a difference in milage or power? Im thinking of cutting the muffler part off my pipe and pasting a Formula MX shrinking chamber onto my muffler. whould it add power? would it be really loud? if i do that would i need to change jets for sure?

Help me out please?
Thank you.
 

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mikuni conversion specs located at bayshore website

be very careful with the jetting, temperature has a lot to do with power and jetting, most sleds run best at -20 C

good tech info availible here jetting baseline

lots of info here too vintage snow carbs
 

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VM30-98 was stock on 78 340 everest,

jet needle 6F9-3 brp #404109200
throttle valve 3.5 brp #404110100
Needle jet 159Q2 brp #404110800
pilot jet PJ 35 #404102700
needle valve brp #404103200
main jet 250 #404100300
 

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I have a 1974 tnt 340 free air chassis i started to restore now I'm shifting gears to my srx 440's fresh spotless motor. make me an offer. I have everything but the seat. good hood. Call me at 414-736-3040 john
 

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I would love to have the VM 34 specs May I please have the vm34 specs for my 1975 340?
I have the VM-34 specs that Ski-Doo used for the "change up" kit for 76. These specs will work correctly for all 74 - 79 340 FC TnT and Everest if you desire a 34 mm. My experience....the 30 mm is just as good as the 34 on the 340 FC
I am not near the specs now, will post em later.
 

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Here is the specs for a VM-34 on a 340 FC TNT and Everest
Pilot jet 20, air screw 1.0 turn out, needle jet 159 PO, jet needle 6DH4-3, slide cut away 1.5, main jet 370.
 
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