My old friend Pete Lovell from the UK just mailed some interesting background information about the Yamaha TX750 Endurance Racer he rode together with Pete Davies, in 1973.
The following information I got from Pete Lovell, one of the riders of the TX750 “Endurance” bike Yamaha Motor N.V. raced in 1973. Pete also corrected some of my mistakes of course!
Pete Davies (2nd left), Pete Lovell (leathers)
Extra information on the TX750 at the Bol'd’Or 24 Hour race in 1973.
The one that Pete Davies and myself rode had a Dresda frame with the Porsche engine.
As I said the rolling chassis was a Dave Degens "Dresda", this chassis was put together by two of Dave's apprentices, Richard Peckett and Pete McNabb who went onto form the P&M company, turning out some very good race machines.
Porsche may have known how to tune an engine but they forgot to rebalance it when they removed the balancer shaft!
The vibration was as bad as it gets. We qualified 9th I think, but
Pete and myself complained about the vibration so much they changed the engine
before the race.
We knew that neither the bike nor ourselves could suffer the vibration for 24 hours with the Porsche engine!
I forgot the specification of the new engine, but it had the balancer and was tuned probably by the Yamaha guys themselves.
I think it was supposed to be standard but we seemed to be staying with some good factory teams with well established riders. Maybe Yamaha did a better job with the stock motor than Porsche.
The big difference was that it was rideable with the balance shaft. To be honest the first engine vibrated so badly that if the new one was no better we had thought of revving it to destruction rather than try and ride it for 24hrs.......!
I started the race and we were lying 6th just behind Peter Williams on the Norton. Unfortunately it started to rain just before P.K. took over for the second stint and although he was keeping position he tried to overtake another rider on the outside and the other rider dropped his machine taking Pete with him.
Rod Gould, Yamaha’s P.R. Officer told P.K. afterwords "you should always try to overtake on the inside because if you drop it when you are passing that's O.K. because you were going faster anyway." The slower rider fetching off the faster one is not good!
It was a shame because with the balancer shaft in it the bike went very well and considering the opposition we were against it seemed very good.
P.S. "P.K." Is Peter Davies. As we were both Pete's, I was P.L. and he was P.K. when we were racing together!
Sorry no pictures you were the only one with a camera!
Hope this is of some use,
For more information read the "Yamaha TX750 story" and its introduction. You can find that easily under "All Articles" on the r.h. side of the Homepage.