How to split a Yamaha engine

[225 Trimoto]

I have a 1984 225 trimoto and it doesn't start. I tried to split the engine to check the valves and I came upon a chain it looked like the timing chain. Or maybe I don't have to split it do you think it is the carb. or what im stumped it runs rough but I have fiddled and fiddled with the carbso much I want to sell it if you guys can give me help thate be great.

[YTZ drew]

Generally, when a valve is making an engine run rough its due to being adjusted too tightly. You don't need to split anything down to check the adjustment, that is done through the access covers on top of the cylinder head. If a valve is damaged or burnt so badly that it still causes a problem after its adjusted properly, then the head will have to come off. The term "split the engine" is usually used in reference to separating the crankcase halves to get at the crank or transmission, which is way deeper than you need to go.

I would strongly suggest obtaining a service manual!

[225 Trimoto]

Generally, when a valve is making an engine run rough its due to being adjusted too tightly. You don't need to split anything down to check the adjustment, that is done through the access covers on top of the cylinder head. If a valve is damaged or burnt so badly that it still causes a problem after its adjusted properly, then the head will have to come off. The term "split the engine" is usually used in reference to separating the crankcase halves to get at the crank or transmission, which is way deeper than you need to go.

I would strongly suggest obtaining a service manual!

How do you adjust the valves and figure out if it is the valves or the càrberatur

[onformula1]

When in doubt read the manual-

http://www.oscarmayer.net/atc/manuals/

[225 Trimoto]

thanks i guess ill need a manual