Snowmobile engine in kx frame?

[Rotorised]

This has recently crossed my mind as an allternative to modifying the 500, has anyone here had any experience or know of anyone that has put a snowmobile engine into a dirt bike frame? I have seen it done befor for hillclimbs but i was thinking of something like a 500-600 twin for trails. Maybe this could see the end of my quest for more power lol   

[don46]

I wouldn't waste my time, I've seen several used in hillclimbers, some work and some don't. there are main issues as I see it, 1. the motor is way to wide with the clutch, at least 12" wider than a K5 motor, 2. getting the clutching right seems to be the biggest problem, make that 3 issues, the exhaust for a twin gets busy.  I don't see the advantage.

[kaw rider]

ATK 700 

[Good]

ATK 700 

I've been in contact with Frank White at ATK.  I'm on the list for when the 700 is built again.  They only build the Intimidator 1 week out of the year.  I do have access to a slightly used motor though...  Too much $$$ for a used motor though for only 78hp...  If I was going to pay $4K, it'd be for a cheetah and 100+hp...  Or like a ZX10R motor or something...

[maddoggy]

i agree with don46. the snowmach. engine idea is not really that great. the clutch adds way to much width, and the clutch is very touchy to set up. if you ride sleds then you'll know that they take quite a bit of maint. to keep them running good. more headache than it would be worth. i am toying with the idea of putting a yzr6 engine in my yamaha warrior. that would make a real screamer and something similar would probably make a good project for a bike as well. wild ideas, MADDOGGY.

[demographic]

ATK 700 

I've been in contact with Frank White at ATK.  I'm on the list for when the 700 is built again.  They only build the Intimidator 1 week out of the year.  I do have access to a slightly used motor though...  Too much $$$ for a used motor though for only 78hp...  If I was going to pay $4K, it'd be for a cheetah and 100+hp...  Or like a ZX10R motor or something...

Could you not get hold of a Maico 680?
Same engine anyway (Maico/Zabel motocross sidecar engine) and as far as I know they are avaliable over here anyway?
Although they get a lot of press the engines are pretty geriatric by the way with a pneumatic powervalve system that uses exhaust pressure to open it.

I had a  250 watercooled 95 Maico with the same system.

[hillclimber147]

An engineer, last name of Tulane I believe, built this polaris race bike. I read up on him and this project quite a bit, very bright guy!! Sounds like it took him a lot of money and time to get the manual clutch set up, let alone everything else he designed and built. I love this concept though, snowmobiles make incredible power. Maybe and easier way to go would be with the banshee motor. They have manual clutches, whereas snowmobiles do not.There are numerous companies that make stroker cranks and big bore cylinders. Even some that have powervalves. Do a search on banshee drag quads and/or sand drags and you should find plenty of info. Also check out www.everything2stroke.com  Keep us informed if you do go with the snowmobile, I love reading about custom projects like these!!

[Rotorised]

Going through the prices this will probably have to stay in the dream bank for a bit longer lol. If i were to do I don't think i would bother with the snowmobile clutch system, the only option i could think of was maybe Frankenstein the 600cc snowmobile twin head onto a banshee gearbox? Would be a f@*#in animal though  those snowmobiles sound awesome 

[chrisorbics]

Hey in 1993 ktm made a 550m and xc model. This is motocross and an enduro version. This has more power than their older 500 but the power is supposed to be smoother. I have never seen one of these bikes but I know they were sold in the united states. i have never seem that atk 700 but I know they made a 406 that is supposed to be a really good woods bike. It is air cooled like the old yamaha yz490 and wr500. I have heard that the old air cooled big bore bikes have severe detonation problems. I am refering to preignition which can wreck an engine. When I sold my 1982 suzuki rm 125 he showed me his rm 465 and he said it is a matter of playing with the timing and running high octane fuel. Are all air cooled big bore two stroke like this? I have never seemed to have any cooling issues or any engine ping from my 1986 kx500 so I figure liquid cooling is the way to go.

Chris