30 BHP Blog

We did make it to the rally and thank god we didn’t have any serious injuries.

Later that year I sprinted badly at the NSA 50th anniversary but did manage to do 1 run under 17 seconds.

then in May 2009 I took the scooter for its first dyno run at Diablos. It managed 22.7 BHP and 19lbs torque.

Disappointed with this result I sent my broken 62mm stroke crank to Chalky at Replay scooters to be repair properly and on the way home from the LCGB Euro at Lincoln I went to Mallory Park where the BSSO were racing to pick it up from him. As soon as I got it I stripped the engine down again to rebuild it as it was always meant to be. This time the crank had a 115mm rod, I Also put the old piston back in which had the inlet side skirt cut, the port timings were:
184 degrees Exhaust, 132 degrees Transfer and 170 degrees Inlet. and less than a month later I took it back to Diablo’s for another set of runs.
This time it was better, making 26.3 BHP and 20 lbs Torque.

For the rest of that year I had no problems at all, the GP got me to were I was going and got there fast enough, including my first Coast to Coast but I knew it had a little more to give, with the 62mm stroke the piston crown was sitting 2mm below the bottom of the transfer windows, I hadn’t lowered them because I didn’t have the 90 degree angled tool to be able to reach them, in the autumn of 2009 I met scouse Mark (he will love me for saying that lol) who had the tool needed and was willing to lower them for me. Lowering them would give a larger transfer area and could only make it better.

When I took the engine apart to give Mark the barrel, I noticed that there were marks on the con-rod and after taking the crank out again it was obvious that one of the weights had come loose again and had been rubbing the side of the rod. I had seen that John at JB Tuning was selling 62mm x 115mm cranks so I decided to buy one. I also bought a new piston which I only cut 2mm from the inlet skirt to give slightly lower inlet timing and re-chamfered the exhaust port.
When I put the engine back together the port timing were now, 186 degrees Exhaust, 134 degrees Transfer and 164 degrees inlet.
In March 2010 I took it back to Diablo’s for another dyno run. This time it produced 27.2 BHP and 21 lbs torque.