I don't understand the benefits of going with premix over oil injection that regulates the ratio of the oil as explained above. 
I very much remember getting my 1st sled in the Fall of 1978.
Yamaha had brought the revolutionary oil injection to the snowmobile industry in the early '70's.
Some of the early oil injection pumps from Yamaha were belt driven.
This led to a few failures....obviously a broken belt quickly blew an engine sky high.
By the time Kawasaki brought out the Intruder/Invaders for the '78 model year, both they and Yamaha were using a much more reliable (gear driven) oil pump.
Polaris, Cat, SkiDoo were literally drug kicking and screaming into incorporating oil injection.
Polaris was dominating cross country racing in the late '70's....and particularly the early '80's with the introduction of the Indy.
I remember Polaris claiming the advantage of pre-mix over oil injection. If you properly premix the oil with the gas in the tank, you KNOW the engine will be getting oil....important when riders were competing in the I-500 race....
There is some truth to that.
But eventually the more reliable injection set-ups were almost demanded by the buying public.
Polaris, Cat, SkiDoo eventually came around....My 1982 SkiDoo Blizzard 9500 was the first year that the Blizzards came from the factory with oil injection.
Hard to imagine today that it took awhile back then to convince some of the manufacturers that oil injection was the way to go.
Oil injection does bring another maintenance item to a sled.....there are probably lots of people out there that would be better off with pre-mixing. I'm talking about people that drag a "barn find" out and get it to run, without ever checking the oil tank for crud, checking the oil hoses, checking the adjustment....on and on....but those folks will probably blow up their sled anyway....
Topic: Oil injection pump removal on invader? (Read 14359 times)