- crankshaft ys 91 bend
- Want buy a new engine !
- OS 91 SZ-H PS muffler pressure?
- screws are getting loose!
- OS MAX 91 SZ with R90: doesn't work properly
- CSpec gold head and pumps
- How schould I break in a OS Hyper .50 ?
- YS 91 versus new OS SZ-H PS (pumped version with regulator)
- gold head c-spec
- OS 91SZ-H going lean after first tank :(
- OS 91 SZH idle
- Cline'd carb settings?
- New Hatori Pipe for OS 91 SZ??
- YS 91 ST Re-Assembly
- OS 50 Hyper losing power at half-tank
- Balancing the fan?
- OS90SZ backplate temp
- Cleaning an engine
- Morgan Fuel (Cool Power)
- Viperhead performance compared to norm OS91 SZ-H Head
- Noisy Engine - OS50 Hyper
- Breaking in a new motor on the bench
- The thickness of the shim for OS 91SZH PS
- Is your Piston Ring worn?
- Crankcase pressure on a SZ 90 PS