I got asked to work on a pair of Yamaha 350's. One has grizzly stickers, one has bruin stickers. Both are 2wd, straight rear axle. Not sure what year. I'd guess '04-'08.
Both have a no start condition. Both have been sitting 2+ years. One came with box of parts the owners 15 year old kid removed to try and get it running.
Started working on one last night. Pulled the rack, front plastic, fuel tank, recoil starter, carburetor.
Removed petcock from tank, cleaned screens, made sure if flows air, reinstalled.
Drained fuel tank, put in fresh fuel, swirled it around, letting is soak and will drain and check it later.
Cleaned up the motor a bit since its covered in mud. Checked the valves. The intake had less zero, actually, probably less than zero clearance. The valve seems like it was hanging open just a touch even at TDC.
The exhaust had maybe .004 clearance. I assume that went to zero once running.
Adjust intake to .008. Adjusted exhaust to .018
Scrubbed the carb in a sink with a toothbrush, dawn, and water. It looked like a mudball.
After that, sprayed it down with carb clean and took it to the bench. A/F screw was 1.75 turns out. I'm thinking this is a factory setting. It seems like this machine was never touched by a mechanic. All the jets actually seemed clear. The bowl had minimal residue in it.
That about as far as I made it for the night. Going to get a fresh plug, clean the air filter, add some fresh gas, and see if it will run. If so, I'll probably clean up the oil cooler before putting it back together. Maybe change the engine oil and rear diff fluid too.