My Dad never sat on a motorbike as far as I know..... I did however have a drag bike that I made in 1990 in SA that I run a few times in the NT and SA.

That's my son who was 14 back then... Its a Subaru Brumby 1800cc motor with a GM 271 blower.

Homemade slider clutch using 3 x datsun plates, I found an old alcohol high pressure pump from a rocket at Woomera (I worked there for a while) so i made a mechanical injection system.....similar to a Hilborn system.

I did a 8.79 1/4 back in 1993 @ 159mph.....a fun thing to ride.
Not a twostroke though.... sometimes a trip to the dark side makes you appreciate things more!!!!
Graham