Help! 07 summit 800 hard starting and fouling plug

[cblair]

sled sat for the summer in the garage with 1/4 tank and stabilizer in it and went to start it the other day so i filled it with high octane gas and got it running went for a ride around the block everything good, got onto lake and opened it up and it shut down, recoil was stuck, but turned the clutch by hand and then the pull cord went, had a vacuum in the gas tank, 4 pulls and it started, run for 1 hr in driveway, shut it down took to the mountains and would not start, tarped it and put a heater to it and got it going but fouled 2 sets of plugs and is hard starting any ideas
thanks

 

[powerteker]

sled sat for the summer in the garage with 1/4 tank and stabilizer in it and went to start it the other day so i filled it with high octane gas and got it running went for a ride around the block everything good, got onto lake and opened it up and it shut down, recoil was stuck, but turned the clutch by hand and then the pull cord went, had a vacuum in the gas tank, 4 pulls and it started, run for 1 hr in driveway, shut it down took to the mountains and would not start, tarped it and put a heater to it and got it going but fouled 2 sets of plugs and is hard starting any ideas
thanks

having it running in the driveway for a hour is not good

I always start mine every fue weeks in the summer

 

[cblair]

the sled did not over heat had snow on the cooler and had it up on a stand working the rpm seeing if everything else was good like the cooling system belt run out but problem is in the starting/ fouling of plugs

 

[pano-dude]

water in gas?

 

[cblair]

no water in gas but pulled motor out today and found the exhaust valve is the cause, leaned out cylinder and took out the top edge of the piston
Full rebuild now, RKT head and piston kit

 

[powerteker]

no water in gas but pulled motor out today and found the exhaust valve is the cause, leaned out cylinder and took out the top edge of the piston
Full rebuild now, RKT head and piston kit

let me know what u think of it after a good ride im lookin for more hp in the spring

 

[cblair]

a buddy has that set up and he was able to walk away from me last winter