Dyno test and problem finding

After Steve Ruth had repaired the stripped thread I managed to get the bike down to Eric at Ekquire motorcycles in Bury St Edmunds, I wanted to find out what the motor was pushing out and get the carb jetted correctly. Every time I come down to Eric's I warm the bike up outside but this day it wasn't having it! I changed the spark plug and eventually she burst into life but still no tick over, (idle for you guys in US....Dave!!!). I managed to get the bike on the dyno and take it through a power run, 64.8bhp at the rear wheel but it was dropping off around 7000rpm. I came down a size on the main jet and set about starting the bike again, but it just wouldn't fire. Eric then appeared and said there was a way to find out if it was fuel related or ignition, so as I was starting it he was spraying brake cleaner into the bell mouth of the carb, when it failed to start he said it was almost definitely the ignition. When I got home I removed the generator, CDi amplifier and coil. Starting with the coil I used a Mega metre to test it, all ok, same with the amplifier box, but when I tested the generator I found that at least 3 of the coils had open circuit. A new generator was fitted and I gingerly pulled the bike back onto the rollers, then with antipidation I let out the clutch, almost immediately the engine burst into life and was idling around the 2000rpm mark. I let the engine warm up then adjusted the tick over to just over 1500 rpm, the motor sound so crisp and by my reckoning it was playing up when Simon was testing at Mallory so what will she go like now the ignition has been sorted?
The bike was now ready for the European Supermono race the next day at Snetterton, and I loaded everything I needed into the van.

Simons first ride

I arranged to meet Simon at Mallory park so he could have a ride on the Mono, the weather was not looking good so decided to put cut slicks in so if the worst came to the worst he could at least splash around for a few laps. I had also geared the bike for Snetterton so it may be a little to high, but will see how he gets on. As there wasn't too many bikes for the session they declared an open pit lane, so Simon headed out for his debut ride on the bike. His first few laps Simon was acclimatising himself to the characteristics of a Supermono, from about the 4Th lap you could see he was settling down and each lap he was going faster by at least 2 seconds! He came in after about 12 laps with his best time being 1'02", but he did say the it was still very damp around Gerrard's and was not really powering out of the corners in fear of a highside. The weather continued to improve and a few small adjustments were made to the Idle speed and gear shift position before Simon took to the circuit again. Even on the out lap you could see that he was more confident on the now dry track and on his first flying lap he got down to just over the minute mark, he could not improve as he hit traffic but after about 6 laps he came in as the session had been Red Flagged. When we were talking about the session Simon noticed that the belly pan had quite a lot of oil residue, and when the belly pan was removed we found the Crank locking hole bolt was weeping oil, I tried to tighten the bolt but it just kept turning. When I removed the bolt you could see that the thresd had been stripped, this had also happened to my other engine when Steve was rebuilding it so it must be a trait of Rotax! I tried to reseal it but with no thread to bite into it was fruitless. I was not happy letting Simon go out again as if the oil got onto the rear tyre it could have him off, Simon agreed but said he couldn't wait to get back out on it as it was "FUN". I will get the bike to Steve this week so he can drill and fit a Helicoil as he had done with my other engine, I have also asked Steve to help me set the carb as its still not idling correctly, more news soon I promise.

PS sorry no photos

The Supermono Cup has been cancelled

It has just been announced the the British Supermono Cup has been cancelled for the remaining of the season due to lack of entries, with this news my rider Ash Norrington, (A cup contender), is unsure if he will continue to race in the Mono class this year. I have offered my Bike to Simon Hedges, a Nottingham rider who has just got hold of a Yamaha SRZ660 that he intends to race in the Mono's next year. He will be riding it in the Eoropean Round at the Snetterton BSB Meeting, and it all depends on the way the bike performs to whether I keep it or sell it.