carls 660 or 685

[13below0]

Hey, Im looking at possibly stepping up a 08 600 IQR. Im looking for some feedback on these or other manufactures kits. Sled has 144"x1.75"track. This will sled will be rode at 0-2000' above sea level. Any info would be great. I usually dont keep sleds around long enough to mod. them but this thing is a blast to ride, especially when we get those big lake effect dumps.

 

[XC700116]

do a search for Carls and you should find a pile of info on the motors in question. I know the search function is crappy and doesn't accept a 3 character search but if you search carls you should find the info your looking for.

 

[donbrown]

There is no replacement for displacement.

Go as big as you can afford.

 

[Supplicate]

There is no replacement for displacement.

Go as big as you can afford.

I used to believe that.



Until I bought a 660. Most fun riding sled I've had in a while. That opinion could change if I ever get around to dropping an 860 in it.

 

[donbrown]

I used to believe that.



Until I bought a 660. Most fun riding sled I've had in a while. That opinion could change if I ever get around to dropping an 860 in it.

I think in this case (pun intended) a 685 will out perform a 660 given everything is the same.

 

[Jonce]

I had a 660 in my 07 RMK and it was a blast to ride. Fill it with pump gas, add oil, then ride all day long with never lifting the hood. It had great throttle response and rev'ed fast! I would do it again, just go with the full kit - SLP pipe, bored carbs and carb boots, plus all the venting.

 

[Hemi]

685 kit

I have a friend with a 685 kit and he can beat up on stock 800's
I didn't believe him when he first told me then we were sledding together and saw it for myself.

I would buy one if I ever sell my t-dragon.

 

[CROW]

The 660 or 685 won't work with the 600 that comes in the '08 IQR. It has a longer stroke than the 600ho. You can however put the topend from an 800cfi on it.

 

[mountainhorse]

Crow is right...

The 08 IQR has the same 70mm stroke of the 800CFi engines.

The 600 HO's have a 64mm stroke.

Also,the Crank bearings on the mag/PTO ends are not oil lubricated; In the RACER engines, they are sealed greased bearings that may need attention every season.. I'd ask around about that. Especially if you pack on lots of miles on the engine.

Many people have gone to 800 CFi monoblock Cylinders/pistons from the 800CFi motors, bored the carbs, ported the cases/jetted/piped them.

If you want more power... ask around in the Race forum on this site and find someone that has a twin pipe, race gas, 600 factory "mod" motor kit for that sled.