I was wanting some help deciding between a 08 660 and a 08 700 or any other suggestions, but I prefer yamaha. I do not know it the 700 has all of the problems workid out for 08. I have heard they boil gas? I will mainly use it for hunting, trail riding, and some work. Any input would be great, thanks.

 

After owning my Raptor 700R wich has essentialy the same engine as the Grizz 700 I'd go for the 700, the fuel injection system is pretty sweet feature to have.
By the way welcome to the forum!

 

The only "bugs" on the 700 are:

There is an oil pressure sensor that prevents the engine from starting without adequate oil pressure. This comes into play in very cold temperatures with oil that is too viscous. If you leave your quad outside when it is zero degrees overnight, and you have 10W40 oil in the crankcase your Grizzly may not start in the morning. Using 5W30 or 5W40 oil lets the oil get to the pressure sensor like it needs to, and your Grizzly will start normally.

The gas tank vent makes a bubbling or buzzing sound that gives the appearance of gas boiling. Gas is not boiling, the tank is just making noise as it vents off excess pressure. It does not effect performance what so ever. And Yamaha changed gas tank vents for 2008, so the "problem" should no longer be present.

 

We've owned three 660s, and two 700s. The 700s are a much better ATV than the 660s were.

Yamaha made a concerted effort to centralize mass on the 700. To understand what mass centralization does, take a 6 foot long barbell that you use for lifting weights, and put a 20 lb weight on each end of the bar. Hold the bar with both hands, with your hands about six inches apart, in the center of the bar. Now rotate the bar first clockwise by ninty degrees, then counter clockwise by 180 degrees, then clockwise by 180 degrees, and keep rotating it back and forth for a few minutes to get a feel for how difficult it is. Then take the same 20 lb weight you have on each end of the bar, and move those weights to the very center of the bar, and grasp the bar again with your hands six inches apart. And then do the same clockwise, counter clockwise rotation thing again for a few minutes. You are rotating the exact same weight you did with the weights at the ends of the bar, but the effort required to rotate that weight is dramatically decreased. Try that experiment and you'll see why "mass centralization" is important.

Yamaha made several changes to centralize mass on the Grizzly 700. They moved the differentials toward the center of the ATV, and now the a-arms are angled, so only the weight of the tire and wheel is at the end of the ATV, but the weight of the drivetrain is more centralized. Yamaha also moved the gas tank down, and toward the center of mass. Six gallons of gasoline is over 48 pounds that was moved to a better location. The center of gravity is also lower, partly because of the lower gas tank, but also because of a lower seat, and because the shocks have been moved from the upper a-arms down to the lower a-arms, and because the engine is mounted lower in the chassis and rotated forward more. All of those changes make for a Grizzly that feels like an entirely different animal. The Grizzly 700 blows away the Grizzly 660 in the handling department; there is no comparison between the two.

The 700 engine is also a better engine. It has dual counterbalancers, so it is smoother running, with less vibration. It is quieter. And it requires less maintenance. The new 4 valve head has much longer service intervals, and does not have the tendancy for the middle intake valve to get too tight that the old 5 valve heads had. The fuel injection on the new engine is also a nice feature, but even without the fuel injection, the engine itself is much better.

The Grizzly 660 was a good ATV, but the Grizzly 700 has made it obsolete. The 700 really is that much better than the 660, and I haven't even mentioned power steering yet. [img]i/expressions/face-icon-small-cool.gif[/img]

 

Mass centralization? Sounds like something you heard on a TV show.

So if the ends will rotate easier what holds the front/rear tires on the ground over bumps?
Sounds like it will wheely and the rear can lift easier. Don't know if I'd want that hillclimbing, oh well the atv warning labels say no steep hills.


Sounds like a good gimmick though.

 

Grizzly 700 is a GREAT quad..buy it. You will not be disappointed. The Power steering is awesome, it is harder to steer my wifes 250 bruin (2wd) then my grizzly while it is in 4wd (yes Rick, 3wd limited slip..not the locker engaged.. Figured I'd save you the time of mentioning the 4wd system [img]i/expressions/face-icon-small-wink.gif[/img] )

A light front end is nothing you can't combat with some body english.. I have not had a problem with being tippy climbing hills.

 

Mass centralization has been a major effort in many forms of motorsports for decades, even if you haven't heard about it Rick. Do some reading on the developments made to improve handling on motocross bikes, and competition off road bikes. Mass centralization is the current "buzz word" in that sport. A motorcycle will feel lighter, respond quicker to rider input, and be much easier to ride because of it. I'm sure it makes more of a difference on a 220 lb dirt bike than it does on a 600 pound ATV, but they are moving more weight to the center with the ATV (like the 48 lbs worth of gasoline in the gas tank).

Nothings going to make a difference with a 900 lb extended wheelbase two seater Polaris though. The Polaris is going to more or less just plow straight ahead irregardless of rider input. So it depends on what you want. If you want something lighter weight, with handling that responds well to rider input, and has more of a "flickable" feel to it, mass centralization helps. The Grizzly has won several shootouts because of its handling, and power steering gets much of the credit. Power steering isn't the only reason the Grizzly has such superb handling though. Mass centralization efforts are also partly responsible.

 

I think people get little over board on the sciences of a ATV. I ride with a 660 grizzly and rode it many times. It has no efi but if you hit the start button it starts up and you can go riding,it does not have the slightest hint of tippy nest compared to any other ATV I rode and I rode many. Power and speed it has more than a normal person will need on a unity ATV.

 

<div class="FTQUOTE"><begin quote>Originally posted by: RickCJ7

Mass centralization? Sounds like something you heard on a TV show.



So if the ends will rotate easier what holds the front/rear tires on the ground over bumps?

Sounds like it will wheely and the rear can lift easier. Don't know if I'd want that hillclimbing, oh well the atv warning labels say no steep hills.





Sounds like a good gimmick though.</end quote></div>

feels a little tippy when braking and turning at the same time, but for hill climbing, It's great. I've gone up hills so steep that the front rack is almost touching my face.