Definately not cheap to run!!!
Rings every 4th race
pistons with every 2nd set of rings
crank every season
Crankcases every 2nd crank
Not to mention shares in NGK and trannies!!!
They were never that expensive to run even when I had my first one back in 1982.
Now with modern oils and better parts available it is more like
Rings every 500 miles
Pistons every 1000 miles (forged pistons are now available for 750,s and last much longer than the origional yamaha ones. I have personally used these pistons for over 1400 racing miles.)
Crank rebuild 1000 racing miles. My current cranks have done over 9000 racing miles using the same flywheels. (German made heockle flywheels.) Now being remanufactured here in the uk.
Cases , Likewise the cases have done a similar mileage and I dont intend replacing them any time soon.
There are approx a 12 to 15 tz 750,s (solo,s and sidecars) now being raced in the uk quite regularely and they are all using cases that are over 25 years old as there as not been any new ones available for many year. However that will change quite soon as the first batch of new cases is currently being made in france so hopefully we may see even more tz 750,s out on track next season.
Rob