Where does the positive wire go from the battery on my 1988 yamaha moto 4 250cc?

Tough one. This discussion is what I have found so far. Moto 4 350 wiring. - Yamaha Workshop - Yamaha Owners Club (yamahaclub.com)

https://www.caretxdigital.com/

https://cdn.partzilla.com/MTE/d/4/MjIxMzIwNw-445f23cd.png

https://www.quadcrazy.com/atvforum/topic/14772-yamaha-moto-4-cdi-box/

https://www.atvrepairmanual.com/download-yamaha-moto-4-repair-manual-200-225-250-350/

Hmmm For the Yamaha yfm225s a parts list and exploded views

The valves are in the top of the engine inside the Cylinder Head.

Valves here .http://www.partzilla.com/parts/search/Yamaha/ATV/1986/MOTO-4+-+YFM225S/VALVE/parts.html

The valves fit inside the Cylinder head shown here.http://images.cmsnl.com/img/partslists/yamaha-yfm225s-1986-cylinder-head_bigyau0288a-5_c208.gif

The valves move up and down indside the valve guide which is number 5 on the above diagram.

follow the thin red wire coming off the battery. you'll find the fuse right away

Assuming you have red and black wires
Red to positive +
Black to negative -

I hope that the starter solenoid has a B and an S on it. B goes to the battery and S goes to the starter. Chaz Moto DC

HI MATE THE CABLES FROM THE ALTERNATOR LEAD INTO A FUSE BOX CHECK TO MAKE SURE THIS FUSE ISNT BLOWN IF IT ISNT GET BACK TO ME