Lost a Cylinder. Many rebuild questions.

[Hammer Down]

I lost the clutch side Cylinder. Engine has 13,100 miles. It still pulls over relatively easy. I included some pics of the plug.
My options are completely rebuilding the top end or buying another 2001 and pulling the motor.
How much is a complete top end rebuild? I know I can pick up a nice 2001 with much less miles than my motor for around $2,000-$2,500.
I want to keep my chassis because it is setup for trails very nicely. I have M10 and viper front end and only 700 miles on ice ripper track.
The big question I am asking is; Is it worth rebuilding the top end on an engine with so many miles on it.?

 

[super1c]

If your going to do a whole top end with 13,000 miles I would for sure open case and send in crank for check over. A new top end won’t cost a ton but not worth doing unless you have the crank checked out and minimum replace seals IMO.

 

[Hammer Down]

Thanks for the info. Does anyone have an idea from the plug picture what the reason for the blown piston is? I'm thinking just high miles.

 

[super1c]

It looks lean but seeing piston will usually tell the tale

 

[AUGDOG]

Thanks for the info. Does anyone have an idea from the plug picture what the reason for the blown piston is? I'm thinking just high miles.

looks like detonation, commonly caused by poor fuel.

 

[Yamaha Nutz]

since it is a 2001 you have the right jetting if stock, the cranks are pretty tough but with that many miles i would have it checked to make sure. the plug shows lean detonation , so either your got bad fuel or a crank seal went which given the age of the sled and the miles i would be the crank seals are done plus do the water pump mechanical seal and oil seal behind it. regardless of your choice rebuilding what you have is the better choice IMHO

 

[YAMMIEGOD3:16]

high miles ain,t doing that to those spark plugs unless bad crank seal 3:16x (yammie tony)