One of Can-Am’s successes, that is still held today, is the land speed record for a 125cc 2 stroke bike. This little reported milestone was achieved in the earliest days of Can-Am as a way of stimulating interest and setting Can-Am on the road to producing a notable road bike. Unfortunately beyond achieving the record little else occurred in Can-Am’s road bike ambitions.
The following article is taken from Phil Mickelson who was instrumental in setting the record. Remembering Bombardier’s pedigree was in snowmobile design, mainly using their Rotax two stroke engines, Can-Am had a ready path to the record.
Phil Mickelson, has a true bachelor’s pad in Duluth, Minnesota. Aside from various self-made, high-tech gadgets throughout his home, he also has a large mural in his entryway featuring Can-Am motorcycles in action in the 1970s. But most impressive is his Wall of Engines, a dividing wall/trophy case between his kitchen and dining room displaying some of his favourite, collectible powerplants.
“When I graduated from college, I had no idea I would become involved in the snowmobile uccess in my region. The year I graduated from college I got a call from Halvorson industry. I raced motorcycles while I was in high school and college and had quite good sEquipment Company in Duluth, Minnesota, a distributor of Ski-Doo snowmobiles. They were expanding their racing team and wanted me to help build racing engines for their team”.
One of these engines was to become instrumental in the Can-Am record.
1. Serial No. 244/732, Rotax, LC Can-Am engine, Prototype engine, 51mm bore, 61mm stroke, 124.5cc, about 32 hp @ 9000 rpm on methanol
At the time of this writing, this engine still holds the modified, 125cc, semi-streamlined class, (APS-AF-125) Bonneville Salt Flats world speed record of 136.537 in 1973. For comparison, a Bonneville-prepared Yamaha, factory prepared, ran 112 to 115 at the same test event that year. The Can-Am record was set in 1973.
The bike was designed and driven by Robert Barker, an engineer with the Can-Am Division of Bombardier, Inc. Barker was a well-known road racer of his time and worked on the design of many of Can-Am’s future chassis designs. Tuning Barker’s bike and assisting at Bonneville were Gary Scott and Mike Cutler. They were well known motorcycle and snowmobile racers and they really knew two-stroke engines.
The engine was the first to come from Rotax with triple exhaust ports and NiCaSil plated bores. The cylinders were in the midst of design for Ski-Doo’s new series of racing engines. This cylinder was first used in a Ski-Doo on the factory race team IFS sleds in model year 1977. The cylinder design also showed up on the 1977 Blizzard X modified sleds, with leaf spring front suspensions, which were used by independent modified class racers.
Gary Robison, the man in charge of Can-Am design, was well connected with Rotax and must have seen the application of the new Ski-Doo racing cylinder on its motorcycle. I believe Rotax modified the molds of the Can-Am crankcases to allow the transfer flow and coolant flow that was required to allow the use of the new snowmobile cylinder design on a Can-Am engine.
A coolant outlet was welded below the front engine mount and a type 254 Ski-Doo cylinder head was cut off near the coolant passage and a plate was welded over it to seal the cooling jacket.
The longest stroke engine built in 1973 for Can-Am was 57.5mm. This engine has a 61mm stroke, which matched up with the Ski-Doo racing engines that this top end was borrowed from. This historic engine has a one-off crankshaft in it.
The engine had no water pump and was thermo-siphon cooled. The backbone of the frame, which was normally the oil tank for Can-Ams, was used as a coolant reservoir. There was no oil injection pump on the engine and the oil was premixed with the fuel.
This engine is certainly one-of-a-kind and has held a Bonneville speed record for 35 years. It is a wonderful example of combined snowmobile and motorcycle technology of its time