I know that the Raptor has an all new engine, claimed to produce more power than the 660 found in the German bikes that Yamaha produces the engines for. However, I thought I'd do a little searching to see what kind of power they were getting out of the old design.
Notice that the old engine would only turn 6,800 RPM and put out 48 horsepower at even less RPM than that? It seems that Yamaha has taken the good and improved upon it, and figured out what didn't work as well as they wanted and changed it.

The new engine in the Raptor is said to turn 9,000 revs and only stop there because of a rev limiter. If a beefed up enine on the old design can make almost 70hp, then new engine would exceed that!

I'm very pleased after reading this!

 

Well if it could get close to 70 hp, u would be blowing away just about anything. The only thing that would beat u is a totally stroked banshee on alchohol, which makes about 80 rwhp. But there just meant for hill shooting.

But really, a good pipe, cam, and high compression piston will prolly be in the low fifties, atleast thats my guess. And thats is plently enough for most riders.

 

I found some more info on the MZ660 and performance upgrades.

http://www.holeshot.com/mz/mzsc.html

This site is selling a slip on silencer and a carb kit that puts out 46 hp and 49 ft. lbs of torque measured at the rear wheel. We've got to remember that this is on the old, unimproved, low-revving 660 and no the one put in the Raptor though. The Raptor is said to easily rev out about 3,000 rmp more than the 660 used in the MZ. I'm not sure what the translates to, but I'm guessing that it is easily about 5 to 10 HP more just based on the eargerness to rev.

If we mangage to get 55 rear wheel horsepower and somewhere around 60 lbs of torque out of it, it should be pretty good huh?

Here's a chart showing torque figures that ScoobyDFW was so kind to gather up in another post.

These figures are for stock machines.

DS650:
27 ft-lbs @3200 RPM
37 ft-lbs @5700 RPM
30 ft-lbs @7000 RPM
25 ft-lbs @7700 RPM

Banshee:
5 ft-lbs @3200 RPM
23 ft-lbs @5700 RPM
29 ft-lbs @7000 RPM
21 ft-lbs @7700 RPM
19 ft-lbs @9000 RPM

Any comments on how the new Yamaha 660 will respond to modifications compared to the existing 660?

Fire away!

 

Interesting that the aftermarket carb is the same as the ron wood stage 1 kit carb for the DS650, except 42mm instead of 45mm.

 

That is very interesting. I guess we won't know until we ride, and dyno them, but I hoping Yamaha redesigning the motor for the ATV chassis is a good thing. Hopefully they won't do like the 400ex and DS650 and make them "slower" than the "normal" motors if that makes any sense.

By the sound of things so far, I doubt it will be lacking power though. But when we can't ride them, it never hurts to share all of the little bits of information we do have and discuss the machines so that when we do eventually get them, we will have some idea of what we are riding on. :-)