Well the 100 did it – 540 miles and a Special Gold 🙂 Go to the trips section for the report.
It was nip and tuck as to whether we’d make the start line but once there the engine felt strong enough to go round – the issue was probably more about my determination and the ability of the satnav to save time.
The engine was back in the frame Wednesday evening and started Thursday afternoon. It ran okay from the start but had two problems. Firstly it wasn’t engaging 2nd and neutral gears cleanly. This was a part of the rebuild that I thought might go wrong as you have to get the selector mechanism set ‘just so’ to ensure everything is in place. I thought I’d got round the problem by removing the gear indicator on the top of the engine. This holds the gear selector and so was just holding it in slightly the wrong position. The idea of removing it worked initially but during the rally it fell into bad habits. Something to sort out when not under pressure.
The other problem was that the bike wouldn’t pull cleanly at full throttle. The plug was very rich but it was starting really nicely. Thursday night I dressed the points and also a spare set just in case. Friday morning I was out early and it still wasn’t sorted. I’d run out of time so went back to the tappets – re-set to 6 thou’ – the inlet had closed up. Torqued the head to 15 Ifb – it pulled down quite a lot and put in the old plug – wondered if the fancy thin electrode was too flash.
Rode gingerly to the start deliberately not giving it full bore as I didn’t want to know if I was going to have to misfire the full 540 miles. Don’t know which of my Friday morning fixes worked but something changed for the better and the bike didn’t miss a beat! The only engine ‘misfire’ was that it sometimes (but not often) backfired through the carb at top speed – experience says this is probably due to slightly incorrect points gap (too tight and therefore advanced).
I was pleased with the front forks. The new nylon bushes got rid of the clunking caused by the worn top bush. I think matters were also helped by the use of SAE 30 engine oil along with the dressed and ‘no notch’ headraces. All in all the handling of the bike was much improved.
I ran a hybrid gearing with my new 420 sprockets. 14/47 which I thought would give me Turismo gearing. However calculation shows this combination is higher than standard 13/45 Turismo and possibily explains the low top speed of 45 MPH and real top of just 42 MPH! The plus side was that second gear was seldom required so in a way this mistake helped me ride round a potentially more troublesome gearbox issue.
Next stop is to try and get the Atlas to run…