To make a 105mm overbore, you must replace the sleeve and bore the engine case. The 102 can be fitted without a sleeve or case work. As for overheating,I run in very hot climates and I have never had an overheat problem with the stock 100mm, the 102mm or the 105mm. Sure, if you jetted too lean, had an exhaust problem, did not properly set timing or sat in one place with the engine on for a good deal of time, especially after a hot run, you may get the temp light until the cooling fan brings everything back to normal.

As for 70 hp -- The MZ motorcycles using the same engine (essentially) produce in excess of 70 hp with a 100mm bore. Yes they do run a slightly higher rpm range but they will produce the power all day long.

On the bottom end issue, undercutting the trans gears, uprating the clutch and springs and adding a performance rod ($135) is all that you might need but remember, the stock case piston weighs substantially more than the JE or Ross 102 or 105mm piston.

Now, for your idea of performance --- name the place and pick the 102 or 105 either way, you will go home crying.

 

Was that "home crying" comment directed to me? I'll be at Dumont over Thanksgiving if your intrested in meeting up. Bring the 105. I'll have 105.5MM in a new cylinder casting along with 4MM of stroke. Mind you, my personal motor is not as fast of a motor as I've built, but it should be more than enough to handle a 727. No nitrous, no alchohol, just real 4 stroke power. Hope to see you there.

 

Let's get it on!!!!!

These are the types of shoot-outs the mags should be covering, hehehe, lol.

Although I doubt this will happen (you guys meeting up together), if it does (I hope), make sure to give us full details Raptor720 and Knutz.

Look forward to hearing from the both of ya!

Swy

 

Hey Chasman
whats this WE crap! i don't want to be associated with your white trash. You white Raptor folks are always stinking up the joint. By the way...how come i never saw the post about you losing to my wife on her warrior. STOCK. If i were you...i'd get off the key board and get my a$$ out there and practice. Blue rules

 

I enjoy a good race. That is what this is all about. Who knows who will win you-me-or some other guy or ?? It is really boring beating Banshees, Bombardiers, 400-500ex's and other stuff.

It sounds like this year, there will actually be some competition in the peanut gallery!

Why wait till Thanksgiving. Lets "get it on" at Halloween in Glamis! I agree with the other comments here -- this is the kind of stuff the mags should write about -- not the staged write-ups of their favorite buddy engine builders who hand out free parts for a page in the mag.

The 105 will be there. I expect I will find you as there is only a couple of the 105's that actually run. I also have a 88 stroker so, let the best be the best and side line the rest!

 

Sweet. you guys have to get this on video and post it somehow.

 

Where ya at KNUTZ?

Let's get this thing scheduled. Too many DS and Raptor owners want to see and hear about this one!

Let's get it on!

 

ok, it is Kuntz Creations working out of his house and through Quad Central in Vegas. Kuntz imports but does not make parts for the DS sled. But for all you DS fans, why not go direct to the source, www.team-pami.de/english
There web site claims 77hp on the Rotax with a 105.5 piston and a 87mm stroke (using a cam ground crank pin). Word has it that the motor was not intended to rev and makes its torque at about 5000rpm.

Gotta love him for trying.

 

Raptor720,

You got it all wrong! He has a DS 650 decked out to 760cc, not a Raptor! I believe I heard some claims that are extremely close to yours, around the 70hp range.

Swy

 

A DS sled vs a Raptor -- gotta love it! Heck, I will put on the stock swing arm just to make him feel bad.