A number of the most popular, most beloved 2-stroke engines in snowmobile history were actually grossly inefficient and EPA dirty.
They simply had to go in an effort by the OEMs to clean up their total corporate average emissions. I call these engines “rotten” because that’s what they’re doing – rotting – in older sleds while the pricey tooling used to cast their myriad pieces literally rots away.
Buck-up! That’s an expression my Dad used when I needed to get tough! There’s hope, sno-mo-groupies and it’s not all bad news!
My list of dirty, rotten engines includes some of our all time faves! In virtually every situation where one of these engines was relegated to the scrap pile, the sport has benefited with a new and better engine that’s more powerful, more efficient and thus able to propel our coveted Snow Bullets even faster and more efficiently up Kevlar Lake.
PART 1: Fuji 488cc Liquid Cooled Piston Port Twin
This engine powered a record-breaking number of Indy 500 variant models and is rumored to be the sport’s all-time most popular engine.
For sure, hundreds of thousands of these simple, mid 80’s-horsepower twins were built from 1989 through the early 2000s by Fuji Heavy Industries in Japan to Polaris engineering specs.
There was no reed-valve induction, no exhaust valves – just simple, straight-forward, tractable, piston port power – and incredible reliability!
The 488’s success was inextricably tied to an Indy chassis free of rolling friction, built out of aluminum (including the bulkhead) and had a P-series clutching duo transferring power that was the envy of the biz at that time.
For sure a much-loved engine that’s definitely missed.
On a lighter note, the Cleanfire SDI engines that replaced the 500 Fuji have helped us a great deal with post partum depression.