Yamaha 660 upgrades?

[Toledo]

Chaps I need more power.

Engine is the 660cc yamaha 5 valve in my MZ Skorpion, I will be using it for more open road stuff next year and it just lacks power above 100km. The engine is the same as in the Yamaha Raptor and a few of their road bikes etc so there should be some good kits out there, Have heard there is a 686 big bore kit available?

Anyone familiar with these engines?

[flashg]

Is it injected ?
I have a 2011 XT660Z tenere,(injected) single overhead cam 4 valve engine,easy to mod with airbox mods and a free flowing exhaust, power commander. Standard yamaha claimed 47 hp at the crank. With these mods mine is 47 hp at the wheel. Big difference, no problem over 100 km's, pulls like a tractor
I wasn't aware they made this engine with 5 valves

[flashg]

Ok did some Google work, and yes they did 5 valve engines.
Your engine is very different than mine and yours is carburetor not injected.
I am aware there are a lot of performance parts for the raptors, be worth chatting to your local Yamaha dealer

[Akzle]

sprockets.




followed by bigger jets, flowing the head, muffler and intake, stroker crank....

[husaberg]

Chaps I need more power.

Engine is the 660cc yamaha 5 valve in my MZ Skorpion, I will be using it for more open road stuff next year and it just lacks power above 100km. The engine is the same as in the Yamaha Raptor and a few of their road bikes etc so there should be some good kits out there, Have heard there is a 686 big bore kit available?

Anyone familiar with these engines?

Stan Stephens tuned (engine it was from memory in a Harris frame) beat a Robert Holden piloted Ducati supermono at the IOM singles race in the mid nineties.
The frame on your MZ was developed from the tigercraft glued racer frame of the same era.
A guy in Nelson has a frame and sundry bits cheap on TM buy these make a chassis up.

The best one I ever seen done, was the RS developments (Russell Savoy)versions they did a twin cam 4V head which is I guess a one off
They also did a suercharged injected version that had a flatter output than std with twice the power.



The 660 5v Yam engines were the DE rigour powerplant for the British singles class in the nineties.

[cynna]

http://www.off-the-road.de/en/XT-660.../Engine-parts/

big bore kit and cams here...... also exhausts and airbox mods. may only fit the newer engines tho

had a mz baghira a few years ago and that was ok over a 100kmh

[cynna]

hmmm can go up to 727cc

just need one of those kits and the usd forks for the tenere and i will be happy

its a great site as well - just got some parts that arrived just over a week

[husaberg]

The Rest of the other article on the supercharged Yamaha 660.

[J.A.W.]

http://www.off-the-road.de/en/XT-660.../Engine-parts/

big bore kit and cams here...... also exhausts and airbox mods. may only fit the newer engines tho

had a mz baghira a few years ago and that was ok over a 100kmh

Wow, that 4T junk is pricey!

May be better off going back to MZ's 2T heritage, & putting a Yam Banshee/RZ 350 mill in it..

Check out something like Vito's ATV performance site.. a sporty ~90hp is better than you'll get - from a ready-to-puke overwrought 4T single..