PROJECT LIKELY FAIL PART IX
The final round of the Yamaha Past Masters (YPM).
The championship is now only days away and barring a few tweaks I think we are ready. At the start of the year this TZR provided homes for a collection of invertebrates as it gathered dust at the back of the Fast Bikes workshop in numerous boxes of parts. Now, as the project reaches its conclusion, it has been entered into the last round of the Yamaha Past Masters (YPM) series and it would appear we are about to see just how likely the ‘likely fail’ is.
I will avoid a roll call of thanks for now, suffice to say that so many people have helped me get to this stage and I am extremely grateful. The plentiful number of decals on my bike are thanks to the companies that have helped me – not trying to make it look more like a race-bike, you understand. A big shout out deservedly goes to Wayne Philips and Phoenix Yamaha of Trowbridge. Wayne has put in the hard yards building the TZR, wrestling with numerous problems in the time that he has grabbed and been allocated by the guv’nor Kev.
One person who has not got a sticker on my 250 is Len Whalin, technical co-ordinator of the YPM’ers. I need to tell you more about this guy and will next issue when Editor Bruce gives me more room. Suffice to say the man is a genius with a TZR, wielding a handy spanner at most things with an engine and a great guy to have in my corner. Len offered to pre-scrutineer my bike which was a great idea as I could arrive at Snetterton for practice day and do exactly that, without having to panic and fluster to get it passed.
There was a big smile from Len as I rolled the TZR out of the back of the van at his workshop; the Phoenix boys have done a great job and Len’s appreciation was welcomed. Before he got stuck into the bike though we had to get stuck into something else: breakfast. Len pulled open a wooden lined draw of his tool box, put two camping stoves on it and cooked up egg and bacon rolls for us (brilliant). Once fed the scrutiny began, starting from the front and working our way back. The front caliper was the first thing that needed attention, lock wiring of course and maybe a 1mm shave of the back as this OE caliper as is running pretty close to the wider front fitted.
Delving deeper Len noted an oil catch bottle needed to be on the gearbox breather pipe. Easy enough to fashion and would only find fluids running into it if I was upside down, so let’s hope
it won’t be necessary. Clutch is good, and though many will fit heavier springs it’s not always necessary – though if I get clutch slip at Snetterton he would fit them for me from his vast bag of spares. I also need to tie in the kick start so it doesn’t start to flap about on track. My notebook was quickly filling up and thank god this didn’t all have to be done when I could be on track.
My gearing is fortuitously good for Snetterton, 14 teeth on the front, 43 on the rear which should deliver on the straights while giving enough mid-range for the twists and turns of the 300’s infield. I will also be the only one out there on standard pipes despite Beej busting to have his F3s fitted and given that the pair weigh half as much as one of the standards, I get it. I would like to get the chance to try them on practice day and see what difference they make, but without the F3 kit, which is against YPM regulations I may be better off with what I have.
The carbs were next. I hadn’t changed the jetting and Len introduced me to the problems with this. I had not thought about it but if you are running premix the fuel is thicker, thus the jets need to be wider – Len removed the 20 grade pilots and put in 27.5s. Bigger jets means more fuel, thus need more air. So the airbox was modified, simply by removing the trumpet which allows more intake. Here came another embarrassing ‘discovery’ – when I had bought the airbox from eBay they stated “will need a new air filter”, fair enough. What I failed to check was if the old air filter was still present – it was and pleasantly rotting away and from my brief runs had flown through into the carbs clogging up the whole job. I am officially an idiot.
So now all back together Len kicked the bike over and it idled beautifully, those few changes complementing the work already done and I felt that we were ready. I was wrong of course. Len noticed the slightest drop of water on the head which became a massive concern leading to a further strip down and removal of the head. Len looked at the skim that had been performed on the head, which increases the compression/power, and decided to ‘test the squish’. There should be a clearance of about .8mm between the piston and top of the head. As it was we had .45mm, thus as the con-rods had expanded with the heat the pistons would have started to make contact with the head, again a potential disaster. So, we either fit a ‘double gasket’ or as was the case, we could fire up the lathe and make it right.
Len had given me eight hours of his Saturday to make sure I knew what was necessary to be race ready, a brief shopping list of a kill switch, lock-wire and a caliper skim that JHS James has agreed to do and we will be ready for the three day meet at Snetterton. Question is, will I be?