I just whipped the heads off and re seated the valves with the aid of a drift and a large lump hammer!
I remember when the R90/S came out early in 1974; I had a good look at one of the first at my local dealer (Allan Jefferies). What a bike! But also what a price! Who on earth could afford to buy and run something like that?
Move forward twenty five years, to 1999 and my friend Alan Gilmore told me that he was thinking of selling his Ex - Hill climb R90/S. I had always resisted buying one as used prices had been and still are to my mind ridiculously high for what is basically a fancy R90/6.
Alan had managed to write his off a couple of years earlier, but had bought back the remains with the intention of putting it back on the road. This was what he was offering me, a project, but with the makings of an interesting bike. The deal was done, and over the course of the next year or so I got stuck into the re build.
The bike came with a replacement frame, and I was under the impression that the original had been deemed to be scrap and the paperwork had been returned to Swansea. It turned out as the work progressed that the replacement frame had been in an even worse accident and was so far out of line that it was unusable. I ended up using a frame from an R60/6 from the correct year, this always amused me later when all the so called experts were giving their opinions on all the non standard bits, not one of them spotted that in reality it was a lowly R60/6 just tarted up with an R90/S engine and cycleparts!
The rebuild went as planned and when I got the bike up and running, I used it for a few Rallies to try it out. One or two teething problems were sorted out and then it was taken over to the Isle of Man for my annual TT pilgrimage.
My usual riding companions, Jim Waugh and Roy Watkinson, both ride modern Japanese bikes, and I found it a lot easier than usual to keep up with them, due to the lively performance of the tuned 90/S. That was until I managed to miss 2nd gear and bend a few valves!
I still had a week and a half of holiday left so I just whipped the heads off and re seated the valves with the aid of a drift and a large lump hammer!!! Well no; I have to admit I couldn't bring myself to hit my pride and joy hard enough to do the job so I let Roy do it for me while I held the heads steady. After that I kept the revs down to a more sensible level and finished the holiday with no further problem.
On my return home the heads were treated to new valves and guides and I rectified a clearance problem by correctly machining the pistons to suit the oversize inlet valves it was fitted with. (Before I had bought the bike it had been modified for Hill climb use and besides the oversize valves the heads are ported and polished and have a modified compression / squish band, it is twin plugged, and has a high lift / endurance cam etc etc).
I then took off the rear set footrests and K&N filters and made the bike look reasonably standard.
Then for a few years it was just used in summer as a second bike, I liked to take it to rallies where its previous owner, Alan Gilmore would be so he could see I was taking care of it! I got a few best bike trophies and it made a change to ride without a fairing, as my normal mount is an R100RS.
All went well until I used it to go to the Tartan Rally in 2007 it appears that the transmission seized as I was on my way home in the fast lane of the M6 the first I knew of it was when I woke up in Carlisle Hospital!
So that's it for now I am back to being the proud owner of a nice project bike and having sorted the paperwork out I now have the original frame all ready to be re fitted with its engine. If only I could find a bit of time, and a few quid to get on with the job!