Joined
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371 Posts
my zx6r project is going no where, KDX is pretty much done and my T350 is almost done (even though it will never be) so I got a 1969 Yamaha YDS-3 today for $100 (I'm the 3rd owner) to make it a look-a-like TD series bike for the track, not going to race it but hopefully go to a few track days this summer.
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Engine was locked up when I was at the guys place but it turns out the rings were stuck. Poured some 2 stroke oil in the cylinders and tapped the fins till they broke loose, spins very nicely now. There is some scoring on the pistons and walls so I will try to start it but I will end up rebuilding the top end anyway. I will keep it at standard bore, maybe swap to VM30 carbs, do some porting, brace the frame and get expansion chambers (hopefully old TD race ones). Body work will obviously be from a TD. Parts are incredibly cheap for the YDS, a lot cheaper than my T350 parts. I havent found a service manual online so I'm lost on what all of the settings are for this bike.
The original 250cc TD's used DS6/D6 motors and mine has a D9 motor, does anyone know what makes these so different? different port dimensions/extra ports? squish? I found a great article comparing the YDS-3 to the RD-56 GP bike but none comparing the D9 engine to the DS6/D6 engines. Just curious as how they differ.
Engine was locked up when I was at the guys place but it turns out the rings were stuck. Poured some 2 stroke oil in the cylinders and tapped the fins till they broke loose, spins very nicely now. There is some scoring on the pistons and walls so I will try to start it but I will end up rebuilding the top end anyway. I will keep it at standard bore, maybe swap to VM30 carbs, do some porting, brace the frame and get expansion chambers (hopefully old TD race ones). Body work will obviously be from a TD. Parts are incredibly cheap for the YDS, a lot cheaper than my T350 parts. I havent found a service manual online so I'm lost on what all of the settings are for this bike.
The original 250cc TD's used DS6/D6 motors and mine has a D9 motor, does anyone know what makes these so different? different port dimensions/extra ports? squish? I found a great article comparing the YDS-3 to the RD-56 GP bike but none comparing the D9 engine to the DS6/D6 engines. Just curious as how they differ.
