How do you set the timing on your 86 yfm200 Yamaha?

There is a hole in the top of the case on the left side of the engine that is used to view the timing mark on the flywheel. With no reverse it will be a slotted plug, you simply remove with a screwdriver. If is has reverse there are 3 bolts that hold the reverse handle bracket on. The big allen head that is the rear most bolt is threaded into the hole. remove that bolt and use a flashlight to look in the hole. While turning the engine over you will see 2 marks on the flywheel, one that says T, and one that says F.

There is also a line on the cam gear and a small bump at the top of the head. Line up the T on the flywheel with the slot in the hole, then line up the cam gear with the bump on the top of the head. You will have to remove the timing chain tensioner to do this so remember to put the tensioner back in after you line up the marks because it will most likely be a tooth off after putting the tensioner back in.

Take your time and get it right the first time. Also make sure the chain is on the crank sprocket and didn't slip off, if it doesn't turn the chain when you turn the crank it's not on. If you're interested, the valve lash is 4 thou for the intake and 6 thou for the exhaust.