A couple of weeks ago I thought it would be a good idea to do an engine freshening.
I got the bike with 700 kilometers on it and it's seen severe service since. It spends the majority of it's time upwards of 10,500 RPM and it's been on the freeway/highway a LOT with a lot of all-day racing.
After all that abuse I wasn't sure what the top end would like like at 22,000 kilometers so I decided to just do it :top: To that end I replaced;
- Cylinder
- Piston
- Rings
- Piston Pin
- Piston Pin Circlips
- Valve Seals
- Valve Springs
- Head Gasket & Base Gasket
I was surprised how little wear there was on the cylinder and the piston at 22K. The piston was scuffed on the load bearing side and the cylinder did have some marks on it but it was minor with a capital M.
Having some understanding of how the engine wears according to abuse and time if I were to 'freshen' it again I would go this route;
- Rings
- Valve Springs
- Head & Base Gasket
and call it done...
For my purposes I wanted a 'factory-fresh' bike for accurate dyno-testing. I wanted 'as new' OEM performance so that's why I went the extra mile.
What did I notice? The engine was quieter and the torque was increased considerably. I mean, nothing major but from a riding perspective hills that I used to gear down and wind the beep out of it to climb I could now lug up in the same gear. So there was definitely more torque post-rebuild.
For the most part though, it was a learning experience on how this particular engine wears according to severe service and mileage. Btw, anyone ever tearing down the engine should replace both the inner & outer valve springs. This was VERY noticeable and reminiscent of the clutch springs.....
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