A fresh motor, fresh paint job on the fairing and a new windscreen.
Saturday morning I took it out for the 1st practice slowly breaking in the fresh motor. It seemed to be running well and I worked the motor up to 7000 rpm and some load. On the 5th lap, it mis-fired a couple of times, cleared for a bit, then died. When I got it back to the pits, I discovered that the intake valve clearance was 0.045", a huge amount. Hmmm, that's odd. Usually you'd expect the valve clearance to reduce as the fresh components settle in. I re-adjusted the valve, but then it seemed like it had no compression and wouldn't start. I checked the clearance again, and I had none. OK, maybe I made a mistake and adjusted the valves on the the overlap rather than on compression. So, I adjusted the valves again and now I had compression and it started. By this time I had missed the 2nd practice, so I arranged to do a 'scrub' lap on the warmup lap of the 2nd race. The motor ran fine below 4000 rpm but wasn't at all happy above that. I checked the valve clearance and it had changed once again. Frank Giannini thought it looked like the intake valve collets were pulling through the retainer. I was less convinced as they normally sit very deep in the retainer and this wouldn't explain the changing valve clearance. But, if they did pull through, it would be disastrous, so I took off the cylinder head and removed the collets and retainer. I had to struggle to get the valve out of the guide, but when I did, it became apparent what the problem was. The valve stem was 'picking up' on the guide and you could see valve guide material on the valve stem. Either there wasn't enough clearance between the guide and stem, or the guide was the wrong material, or it wasn't getting lubricated properly. In any case, this wasn't going to be fixed before my races were up.
I had noticed that Joe Traino's CB 350 Honda with an XL 350 motor in it was pitted next door with a for sale sign on it.
|Joe Traino's CB 350 Honda powered by a '74 XL350 motor|
|The bike was built by Stan Lipert many years ago and is for sale for $3500|
Two years ago, I turned high 1:33 minute laps winning the V-1 and V-2 races. This time I turned a low 1:37. Does that mean that I'm getting old? Or that practice DOES help? Or that a tach DOES help. Or that the track was faster then? Who knows? In any case, my thanks to Bill and Joe for salvaging the weekend for me.
The Stan Lipert built XL/CB 350 is a fun bike and a good value at it's asking price of $3500. If anyone has interest in it, they can get in touch with me and I'll pass on Bill's contact info.
It was a light turn out for both the vintage and modern classes, especially considering how beautiful the weather was. I hope we can just chalk that up to it being Mother's Day Weekend and that it doesn't represent a trend.