Gas/oil ratio? - Snowmobile Forum: Your #1 Snowmobile Forum

Kellxr7 · 12-23-2006, 10:52 AM

I recently got a deal on an 81 Blizzard 5500 with a 496cc rotax, & I am wondering what my fuel mix should be, any suggestions? Being its an older sled with a few miles I plan on using el cheapo oil. I went with 50:1 for the first tank.

upersleder · 12-23-2006, 12:18 PM

50/1 is right

eric phazer · 12-23-2006, 01:00 PM

50:1 sounds good to me, thats what i run.

but if you have concerns then run 40:1

badbrad · 12-23-2006, 01:26 PM

50:1 is the usual.

SSnthe10s · 12-23-2006, 04:43 PM

my ol moto ski ran 32:1.

upersleder · 12-23-2006, 08:40 PM

yea back in the day when oil was not as good and engineers didnt know alot about effects of too much lubrication mixes were up to as much as 15/1. they also went thru alot of plugs. i remember dad keeping a whole box under the seat of the old 68 mustang

IndianRvrShiver · 12-23-2006, 10:46 PM

When I raced Karts (back in the 70's & 80's), I would run as rich as 12 oz of Union Carbide Syn / 1 gallon of methanol.

Would use a box of plugs over a w/e, but the longest they had to last was a hour (length of an enduro race).

Fixitguy74 · 12-24-2006, 10:36 PM

I belive the stock ratio on that Doo is 32:1 especialy if your using the cheap oil. To add to the confussion about mix ratios, if you run a heavier mix say 20:1 or 16:1 you could squeeze out more horsepower (probably less than 1 HP). The extra oil helps the rings seal better, for maximum compression. You do risk eating more spark plugs though. Make sure to set your plug gap for that model at .18 inches. They were famous for hard starting if the gap wasn't set right.

Steve

**RJ Gleason** · 12-26-2006, 12:15 AM

^^^^Make sure to set your plug gap for that model at .18 inches.^^^^^^

I think you mean .018 inch.

Fixitguy74 · 12-26-2006, 03:59 PM

Quote:

Originally Posted by RJ Gleason

^^^^Make sure to set your plug gap for that model at .18 inches.^^^^^^

I think you mean .018 inch.

You're right. My bad.

**RJ Gleason** · 12-27-2006, 03:19 AM

Book says 50:1 with concentrated Bombardier oil and as recommended by manufacturer if using any other oil.
Most of the newer oils are designed for injector use, I recommend 40:1 if you are using this.
If you are using oil formulated for pre-mix, if it is synthetic or a blend, you can mix at 50:1 .

Fixitguy74 · 12-28-2006, 01:59 AM

Quote:

Originally Posted by RJ Gleason

Book says 50:1 with concentrated Bombardier oil and as recommended by manufacturer if using any other oil.
Most of the newer oils are designed for injector use, I recommend 40:1 if you are using this.
If you are using oil formulated for pre-mix, if it is synthetic or a blend, you can mix at 50:1 .

Your right, so my bad once again. Once I read your post it hit me that I knew this and don't know what I was thinking when I posted. Sorry for any confussion I caused.

upersleder · 12-28-2006, 09:19 AM

all this for a guy who never came back to find the replies