Finally have my Sidewinder

[journeyman]

I hesitate to get this thread derailed yet again but here's the most dependable, reliable, and proven 2-stroke motor on the market today, and it's made by Yamaha!....

Not to mention that it's got world class handling and comfort with the front Telescopic Strut Suspension that's just begging for you to take some sweet jumps!

https://www.yamahamotorsports.com/2-up-touring-utility/models/vk540

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I've got a pretty strong feeling that YMC (Yamaha Motor Corporation) just might have what some of us have been waiting for coming in the near future in a new 2-stroke.
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Hard to argue those little fan cool Yamaha's!

Way back 2o years ago or so I was talking to Olav Aaen in person. He had a test track at his shop he ran a go cart with a snowmobile engine in it for testing all sorts of snowmobile clutch parts in the summer months. Over the years he said he had a few different engines he used in it. He claimed the redhead 700cc Yamaha triple with his triple pipes was the toughest motor he ever had seen. Said he literally beat the tar out of that thing and it never missed a lick.

He also said he was dead against 2 stroke twins much larger than 600cc. Said the coffee can cylinders lead to poor fuel scavenging, they use less efficient bigger carb diameters and lend to poor cooling. He liked at the time Yamaha was using three cylinders with above 600cc machines of the time with small bore racked carbs which gave them very quick throttle response and better cooling with the smaller cylinder areas.

Gotta laugh and agree on the take on the current 800/850's!! It's not if they are gonna blow.......just when! I don't think all the emission rules are helping their cause though. Start leaning them out on oil and you know what happens!

 

[journeyman]

QUOTE="stevewithOCD, post: 1485683, member: 8597"]DEAL!
JoMary trails are some of the nicest trails in all of Maine in terms of grooming, scenery, slaloms with double lanes all the while Mt Katahdin is GLARING at you reminding you of how SMALL & INSIGNIFICANT you really are.
That's why the majority of my riding is there....

These pics ought to make your summer LONGER!
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I get butterflies just thinking about squeezing the throttle to the bar in that first photo!!

 

[ClutchMaster]

Hard to argue those little fan cool Yamaha's!

Way back 2o years ago or so I was talking to Olav Aaen in person. He had a test track at his shop he ran a go cart with a snowmobile engine in it for testing all sorts of snowmobile clutch parts in the summer months. Over the years he said he had a few different engines he used in it. He claimed the redhead 700cc Yamaha triple with his triple pipes was the toughest motor he ever had seen. Said he literally beat the tar out of that thing and it never missed a lick.

He also said he was dead against 2 stroke twins much larger than 600cc. Said the coffee can cylinders lead to poor fuel scavenging, they use less efficient bigger carb diameters and lend to poor cooling. He liked at the time Yamaha was using three cylinders with above 600cc machines of the time with small bore racked carbs which gave them very quick throttle response and better cooling with the smaller cylinder areas.

Gotta laugh and agree on the take on the current 800/850's!! It's not if they are gonna blow.......just when! I don't think all the emission rules are helping their cause though. Start leaning them out on oil and you know what happens!

Olav was a genius, and nice guy too boot. Talked with him several times and even bought a sled from him. The problem with the big bore two strokes is the exhaust port is so large the rings end up being unsupported for a long length. If they wear even slightly they will catch the port and score the cylinder/piston. Big bore two strokes also have issues with breathing properly like you mentioned.
With all the technological advancements you would think engineers would come up with solutions, all I can say is good luck finding an engineer at the level Olav was at! Seems things have gone backwards IMO.

 

[journeyman]

Olav was a genius, and nice guy too boot. Talked with him several times and even bought a sled from him. The problem with the big bore two strokes is the exhaust port is so large the rings end up being unsupported for a long length. If they wear even slightly they will catch the port and score the cylinder/piston. Big bore two strokes also have issues with breathing properly like you mentioned.
With all the technological advancements you would think engineers would come up with solutions, all I can say is good luck finding an engineer at the level Olav was at! Seems things have gone backwards IMO.

I used to run into him at the Thirsty Whale on Lake Minoqua during the Mid America ice drag series (early 90's). I used to help pit crew for a friend that ran Polaris (Felegy) motors though I was a Yamaha guy myself. Same circuit Knapp raced in when he was sponsored by Arctic Cat. I also did a couple of Olav's clutch tuning and carb tuning clinics he used to offer back then. Yes he is a really sharp guy! He started out working on large diesel ship engines right out of college. Then he landed the job with Evinrude (OMC) where he got the snowmobile bug. From there he started doing some stuff on the side like hand building tuner pipes and just showing up at all sorts of races and handing racers some exhaust pipes......here try this and quickly the word spread. In a few years he went on his own opening up AAEN Performance.

Sorry off topic but hey we are off season...right?

 

[74Nitro]

I used to run into him at the Thirsty Whale on Lake Minoqua during the Mid America ice drag series (early 90's). I used to help pit crew for a friend that ran Polaris (Felegy) motors though I was a Yamaha guy myself. Same circuit Knapp raced in when he was sponsored by Arctic Cat. I also did a couple of Olav's clutch tuning and carb tuning clinics he used to offer back then. Yes he is a really sharp guy! He started out working on large diesel ship engines right out of college. Then he landed the job with Evinrude (OMC) where he got the snowmobile bug. From there he started doing some stuff on the side like hand building tuner pipes and just showing up at all sorts of races and handing racers some exhaust pipes......here try this and quickly the word spread. In a few years he went on his own opening up AAEN Performance.

Sorry off topic but hey we are off season...right?

Maybe sometime I'll start a thread about sharing old racing stories and see if there is interest.

 

[VX1R]

Maybe sometime I'll start a thread about sharing old racing stories and see if there is interest.

74 Nitro........Sounds like a great idea for a thread.