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fuel to to oil mix

PostPosted: December 16th, 2003, 3:38 pm
by sno*jetfreak1
what do u guys recomend for a 1973 snojet, modle: star jet, its got a 340 yamaha engine, and it is fin cooled, single tilloston carb, i have been running it about 30:1 but after every ride, the next time you go to fire it up one plug is dead, i have rebuilt the carb several times and tried hotter plugs, currently i am using NGK B8HS plugs, what are recomended by the manufacture, 40:1 would probably be ok when its real cold but i'm worried when it warms up, any input is greatly appreciated!

fuel to to oil mix

PostPosted: December 17th, 2003, 9:08 am
by sno*jetfreak2
my sled manual from 74 states 25:1 for the 340's in it. So i am sure 30:1 will do it unless your running it in summer.

fuel to to oil mix

PostPosted: December 17th, 2003, 8:20 pm
by Ocean State Sled Head
I would run it 40:1 with some really good oil, like Yamalube.
The manual recomends 20:1, but this is too rich. This is why your plugs get fouled.
When the books says 20:1, thats when there was leaded gas.
The new oils are better, and today's gas has no lead.

Your factory plugs should be BR9EV with a (.020 -.024 inch) or
0.5 - 0.6mm electrode gap.

Go to your local sled dealer, and buy a book called Snowmobile Service Manual 11th Edition by Intertec Publishing. This book covers all sleds up to 1986.

fuel to to oil mix

PostPosted: December 18th, 2003, 9:02 am
by sno*jetfreak2
Actually the manuals specifically stated to use premium gas which was unleaded in the mix. So don't screw with the mix ratio too much.

fuel to to oil mix

PostPosted: December 18th, 2003, 9:22 am
by sno*jetfreak1
is yamahalube synthetic oil? and is it a good idea to use synthetic oil in an older machine

fuel to to oil mix

PostPosted: December 18th, 2003, 8:28 pm
by Ocean State Sled Head
It's not recommended to use synthetic oil in old sleds. Stay with the real oil. I still say run it 40:1 for best fuel consumption and performance.