i recently bought a 1975 yamaha ty 80 b. i run fuel oil ratio 40 to 1. do you need expensive 2 stroke oil. will using i use semi synthetic cost around £9. should i use castrol or will regular scoooter motorcycle 2 stroke work.well. also what compression should a ty 80 have the haynes manual states 78 psi warm engine>?? 78 psi seems low. piston and rings look ok.i had to order new head gaskets studs becuase the owner before had used a cut off piece of gasket.it was circle had the edges cut offf and it failed. had exhuast gases blowing out from the cylinder. cost around £70 to buy 4 new studs 4 new bolts gasket set. i am an adult but becuase i dont have a trailer to transport my bike a ty 80 fits in the car boot. i am around 12 stone. will the engine last carrying my weight.i know this sized bike was desighned for 5 to 12 yr olds not fully grown man but its a fun bike to ride.its my first motorcycle.
