This is going to be a long post, so bear with me…..New to the forum and this is my first post. I recently picked up a 2006 Grizzly 660 for cheap. Owner said it ran but could use a top end rebuild. I rode it and agreed on the price.

Ordered a replacment 660 cylinder, piston, rings and other required items. It had a 686 big bore but I want to go back to factory displacment. Got the head and cylinder off then ordered new valves, valve seals and a Raptor center intake valve spring to use with the Hot Cam Mudbuster cam it came with.

Got the head rebuilt ready for install. Then comes something I feared…..I checked the play in the crankshaft connecting rod. Plenty lf side to side play and it has play up and down. Did different methods of testing it and it for sure needs replacing. So I ordered a Wiseco crankshaft kit and removed the engine from the frame…..easier than I thought it would be.

Now my problem, I grew up riding and racing dirtbikes. Rebuilt a fair amount of 2 and 4 stroke motors. But the dirtbike motors have far less to them then this thing.

So I’m wondering if it’s possible to simply split the cases to get to the crank. Or do I have to strip everything off the engine to get to the point of splitting the cases? I haven’t really inspected the motor as I just pulled it out and the wife wants to go to dinner. I do have a Clymer (? Spelling ?) service manual for the atv. Wish it was a Factory Yamaha manual, but it was given to me with the atv.

Im not really worried about removing the crank or installing the new one, I watched and ready plenty of methods on that. I’m just not wanting to have to remove everything from the engine unless I have to. So what do you guys say? And sorry for the long first post.