i have a question to anyone who can help out. i have an 87 yfm moto-4 225 and the problem is that i lost all the bottom end power on it. once i get going it rips at its usual pace but i got no torque which is a real pain in the ***. if anyone can help please do, and if anyone knows of any mods for this old beater, please share those too
thanks

 

it could just have low compresion. on a bike that old i would say it deserves a rebuild