Curiosity finally got the better of me so despite the aching ribs I lifted the little RS50 onto the bench, binned the fairings and dropped the heart out to see what went wrong. 2 stroke tuners learn some pretty painful lessons some times and I generally like to believe I've gotten through the thick of the really hard ones. So it's disappointing to get chucked off at high speed by a fault of my own which I should have prevented.
When you race a smoker enough, you become extra aware to the world around you. Any change in ambient temperature, humidity or wind, prickles on the back of your neck. And when you race tiny smokers, you become extra sensitive to the details of racing: am I using all the track, did I hit top of top gear, am I hitting my RPM change point every gear, which corners am I out of the power. It all has a huge impact, and you actively change your setup to accommodate the conditions.
I'll let you put this one together with me:
1) It's stinking hot. 26 degrees by 9am, 32 degrees in the shade mid day
2) I didn't get the head off after taking the 50 out at Ruapuna the first time
3) The engine and carb was set up to race on a kart track. I hadn't changed from what I ran in Auckland.
4) I hadn't replaced the engine coolant in a while and the water had started to contaminate
5) I didn't finish fitting up the temperature gauge
This 50 is a F5 racer, what most people call a bucket, and I had unknowingly adopted the bucket racing mindset. The lazy, she'll be right, just put fuel in it and go mentality that's not suited to a 2 stroke putting out almost as much HP per litre as a 125GP bike. If I was in my normal rhythm, I would have pulled the plug and head after the first day or session to check everything was all good. I would have gone up on the mid range and main jetting in the first sessions on a full track then worked towards the optimum. I would have aired on the side of rich to deal with the stinking heat. I didn't and I believe I overheated the poor little thing.
Before I pulled the engine down, it did turn over by hand. The 4 corner seizure in the photos below tells a lot. This is often either from not enough piston/bore clearance to begin with or overheating. The cylinder is scuffed up but not as badly as I was expecting. Heading into the nationals, it was a pretty clear wake up to get back into the right racing mind set. To become as mechanical and precise as you should be racing 2 strokes. Consider this lesson learnt again.