Just when I thought I was out Scott Potter from Texas mailed me to say he has a 52,4mm piston and rings. By Friday the piston was with me along with a couple of freshly refaced valves and a head and base gasket. Back in business!
Had to spend a lot of time on the valve seats. The exhaust seat in particular was very badly pitted and in truth ought to be re-cut. Time was against this solution so I carried on with the grinding paste and ended up with a decent enough finish. Held off putting the valve springs and colletts back in until Monday…
I also spent quite some time on the bore – honed it with some 120 grit emery. In the process I found this rather worrying score…Some more grit and it is now smooth to the touch and as with the valve seats no time to consider rebores or somesuch…
Anyways progress was being made in the kitchen so it was time to get Mrs A to help me get the piston in the bore. Observant readers may have noticed the piston appears to have 5 ring grooves!
An email exchange with Scott said not to worry the apparent top ring groove is in fact just a ‘recess’ hmmmm whatever no time to question that – but it would be a bit OTT to have five piston rings on a 100cc piston wouldn’t it. Four it is!
So anyway Mrs A and I struggled on and once done the engine was taken down to the garage. I fitted the forks (I hadn’t been completely inactive during the week – I picked up a set of headrace bearings from a bicycle shop!) and new nylon fork bushes. Slotted in the front and rear wheel + fitted the front mudguard. Time was going away from me so I thought I’d just slot the engine in the frame before calling it a day and damn me I’d put the barrel on back to front!
So there it is less than a week to go and still a fair bit of fiddling to do. To finish off the day I get an email from Keith to tell me my rally route is one checkpoint short…I suppose better to find out now than later.