Attention PG Yamaha / Don Pickering -
As a snowmobile performance enthusiast, I have been modifying my snowmobiles (engines and chassis) ever since made it to the top of the Renshaw Mountains (McBride) in about 1989. I till remember adding white plastic paddles to the track, then having to drop & roll the chain case to clear the big paddles. What a difference it made, especially after the long tracks (136”) came out! It took about 10 years for the four big snowmobile manufacturers to catch-up and realize our local market, and then the “rush to the mountains” really started!
During that time I was buying the closest thing to a mountain sled, with the biggest motor I could get. About the same time I started playing and experimenting with turbo-chargers for my two cycle engines. I found out this made about 50% more power and lost very little at altitude. The biggest problem with adding a turbo to a two cycle engine is that it produced a lot of heat, which ended up on top of the aluminum pistons. Although WISECO came out with high silicone aluminum pistons, they were no match for the heat the turbo threw at them. This took quite a while to figure out the jetting, and it was not until I put one on a two stroke Yamaha 600 that came out (I think in 1997) with electronic ignition and smart carbs, that automatically retarded the timing to prevent detonation. This proved to be the ultimate “mountain sled” because of the lightweight two cylinder engine, improved 2” rubber track and TURBO-Power!!
Well as engines got bigger, tracks got longer and the sleds got heavier, I moved my Turbo to a 800 twin engine and a new sled. I never did get it working as well as the old 600 c/c engine because the Turbo was limited on the volume of air, and could not efficiently fill the cylinders. I acquired a larger Turbo, but got “horn-swaggled” (the polite way of saying I got “suckered”) into sending it back to the States, by a fast talking salesman after they found out AeroCharger went out of business.
My apparent mistake really hit home, after being barely above stock sleds at the time, but I really got spanked when the heavy RX-1 came out (turbo-charged). A lot of people shied away from this sled because of the extra weight to carry the 4-stroke, 4-cylinder, 1000 c/c engine. After a sound “trashing” it became immediately apparent about the huge advantages of putting a turbo on a 4-stroke engine! I believe this is where the first application was (aeroplane engines in the 2nd world war flying at high altitude) on four stroke engines. Anyway, shortly after peering into the hood & wondering “what the hell that thing was”, I realized that the 4-stroke engine was the perfect match because it “sheds” the heat (fires on every other stroke), and the double power is quite adequately handled by the modern ignition and cooling systems.
So, upon returning to town the 2-stroke snowmobile was immediately put up for sale, and I sold both my old AeroChargers back to the USA (ya, you guys can have all my old stuff now!). I still laugh when someone sneers when you pull up to the bottom of a big hill with the “heavy RX-1”!! Then you blow over the top as they are turning out, a quarter of the way up. The second thing I quickly realized, the weight is not a consideration if you have the POWER!! And finally I sure don’t miss buying race fuel!