First meeting of 2018

April 23rd, 2018

It's well into April, and my season has only just started.  But that's not to say it's been a quiet winter.  After the ZXR 750 disgraced itself on the third lap of the Classic Superbike TT, I took the motor out and gave it to the good chaps at Dynotech.  They stripped it and announced, to everyone's surprise, that the crank had snapped in two!  So I sourced another L series motor, and Andy at Dynotech made one good motor out of the two, mostly using the bottom end of the 'new' motor, and keeping the head work from my original race motor.  On the rebuild, Andy found that both water pumps were damaged (where the pump takes its drive from the engine), so he sourced another one for me from ebay for 20 quid.  More of this later...

I fitted the motor, with help from the good Simon Wilson, and fairly methodically plumbed in electrics, carbs, exhaust, radiator and coolant.  It fired up pretty easily, and a couple of days later we ran it in on the dyno at Dynotech; at the end of this we did a quick power run, and got a peak of 125bhp - with a new motor, and the mixture very slightly rich,  I was happy enough with that.

The TZ engine is with Graham File, after it went off song at Donington last October.  Popping the heads off, it looked like the front cylinder had injested a foreign body of some sort.  For those who don't know, Graham is *the* guy to build your TZ motor in the UK.  I had hoped to have it back by now, but Graham is making sure everything is *just right*, which for a 2-stroke at the TT, is what you want.

I had been thinking of doing the NGRRC meeting at Brands Hatch in early April, but Britain was hit by a late touch of winter, and the meeting was cancelled due to the forecast snow and sub-zero temperatures.  Which was the right call, because the cold and snow arrived as predicted.  The next potential meeting was two days at Jurby, on the Isle of Man.  It's a long way to go, but as racers from the UK get discounted entries and ferry crossings with Andreas Racing Association (ARA), it's not as expensive as you might think.  And I've got lots of mates on the Island, so it's a chance to catch up with them, too.

I loaded the van up with ZXR and all the racing paraphernalia to go with it on Thursday evening, and headed  up the M40 and M6 on Friday afternoon.  Traffic was as appalling as I remembered, and it took over 5 hours to do the 200 miles to Liverpool.  But we made the boat, had something to eat, chilled out, and I drove off the boat into Douglas with a smile on my face, as I always do when I go back to the Island.  We even managed to arrive at Keith & Becca's in Ramsey in time to have a night cap.

Next day I was at the track in good time, and set about putting up my  <drum roll> new  awning!  The last one had done 4 seasons, and the storm at the last meeting at Donington in October had shredded most of the canvas, so I decided to shell out on a replacement.  And this one is stronger, lighter, and has a white (rather than green) roof, so the light inside is much more, er, natural. 

ZXR in new awning

The forecast for the day was good, and so it turned out. 

Sunny Jurby

I did the usual race day things - signed on, got scrutineered, fitted transponder, put the tyre warmers on, and eventually the time came for my practice session.  Out I went, on a dry track, that I knew well, and I felt at home straight away. Until about my 4th lap, where the acceleration didn't feel quite as strong as it had.  And then my foot slipped on the footrest, and I looked down and saw oil.  Oh dear.  Straight to the pits, bike on stand in awning, and the investigation started.

I dropped the belly pan off, and immediately saw oil *and* water - what was going on?  Looking round the engine, the cause of the oil leak was pretty obvious - a bolt in the side of the cylinder block, which locates the pivot for the cam chain tensioner blade, had wound itself out.  Fortunately, it was still sat there, but because it was no longer engaged with its thread, I struggled to thread it back in.  While I was wrestling with this, and figuring how else to get access, paddock neighbour Rhys Hardisty came in, saw the problem, grasped the bolt between thumb and forefinger and immediately managed to thread it back in.  Thanks Rhys - you have the magic touch!  Meanwhile, Vanessa had been cleaning out the belly pan, and presented me with a small 6mm bolt with a copper washer on it, with the words "Is this important?"   "Probably", said I, and started looking for its home.  Remember the replacement water pump I mentioned at the beginning?  Well, I hadn't stripped it, nor checked fastener tightness before fitting it, and the bolt had come out of the bottom of the water pump, which explained the water as well as the oil in the belly pan.  There wasn't a lot of water there, tho, so I didn't think any damage would have been done. 

So, with oil and water topped up, all the oil cleaned off the bike and rear tyre, and everything back together, I was ready for the race.  Or so I thought...

I'd qualified 9th, which was ok for my curtailed session, so I gridded up on the third row, the lights changed and we were away.  The fast boys at the ARA meetings at Jurby are properly fast nowadays, and they we soon gone, but I made a decent start and wasn't doing badly...until lap 3, when I saw some steam and water, and noticed water spraying onto my right leg.  I put my hand up and pulled back into the paddock.  Water was overflowing from the radiator catch tank - not a good sign.  I dropped the fairing off, put on leather gloves, and at arms length removed the radiator cap - a lot of hot water and steam jetted out (don't try this at home, kids).  I replaced the lost water, started the engine without the radiator cap, and immediately saw the tell-tale signs of a blown head gasket - the cooling system was being pressurised by escaping exhaust gases.  Bugger.

The odds of changing a head gasket in the next 18 hours were pretty slim, but I did try to track one down on the Island, but to no avail.  But then something happened to change the weekend from a complete disaster to a minor victory - the amazing Andy Cowie offered me the use of his "steelie" - his 1996 Yamaha Thundercat.  The same bike that I've ridden twice with him in the ARA end of season 4 hour endurance event.  Yet another reason to race with your mates at Jurby!  So at the end of a gloriously sunny day, I headed to Andy's with the van and collected his venerable steelie.

The evening was convivial and friendly, and we caught up with manx mates over dinner at Keith & Becca's, including an impromptu celebration of Andy Stewart's birthday.  This may have contributed in some way to the state Vanessa was in the next day; I was racing so "just had one glass of wine to be polite".

I left Vanessa nursing her head the next morning, and headed back to the track.  I needed to tweak a couple of things on the steelie before scruting - it had just been parked since last year's endurance!  But I soon had it right, and scruting wasn't a problem.  Practice was good, but I was a different bike, and everyone else had got their eye in yesterday (althought the circuit was run in the opposite direction), so I only qualified 11th, with a best lap of 1:21.  This is much slower than usual for me, having got down to 1:16s at the endurance last year, but softly softly catchee monkey.  The Thundercat really is great to ride - it's got really surprising mid-range for a 600 from the 1990s, and steers and brakes smoothly and confidently.

Rain was forecast, and it tried a few times, but never came to anything, so swapping wheels was never something to worry about.  I gridded up for race one on the 4th row and got a decent start, as usual.  Once again, the fast boys were quickly away, but I found myself chasing three other bikes which were running at a similar pace.  About now I had an angel and a demon perched on my shoulders - the angel said "You're on someone else's bike, and all you need is a finish"; the demon said "Catch them, pass them, wave goodbye".  Which of these two do you think I listened to, dear reader?

On the last lap I was right on them, and got great drive onto the back straight, passing one bike (Steve Beal) on power, and the other (Jack Hunter) on the brakes into the bus stop.  Hah!  I kept the advantage to the line, whooping inside my helmet.  Result: sixth overall, 2nd in class, best lap of 1:18.3

At this point I had my finish, I'd had my fun.  If we'd had time, I'd probably had rushed to catch the afternoon boat home, but that option had gone with a few delays in the programme.  So I decided, after checking with Andy, that I was there anyway, so I might as well get the track time, on a cold, windy, but still dry afternoon.  I checked oil and water, topped up the fuel, and gridded up for race 2.  By this time the cold and wind had deterred a few people, and the grid was a bit thinner.  The lights changed and off we went.  I soon found myself chasing Jack Hunter again, but he usually has the beating of me, and this time just rode away,  with a best lap a second faster than my best.  Steve Beale got past me too, but I latched on to him, and passed him on the straight on the penultimate lap.  I knew he was there, though, and fully expected an attack at the bus stop on the last lap, and so it turned out.  But his outbraking manoeuvre was waaay too ambitious, and he came sailing past me without a hope of making the corner, and continued onto the grass.  He stayed on, and regained the track, but a few seconds behind me as I crossed the line.  Result: 5th overall, 2nd in class, best lap of 1:18.8

So then we packed up, loaded the van, said our goodbyes, and headed to Douglas, for fish and chips, and then the ferry home.  We both managed to doze on the boat, which made rolling off at gone 11pm and driving for 240 miles (from Heysham this time, not Liverpool), a bit more tolerable.  Home at gone 3am, and straight to bed.  That's racing!

Last meeting of 2017

November 1st, 2017

After two DNFs at the Classic TT, I was a 'signature' further away than planned for my 2018 TT Mountain Course licence (everyone calls them signatures, but nothing actually gets signed - you just need to finish a race on a day, six times; qualifying for the TT or Manx also counts for 1 'sig').  So I looked to see if I could squeeze something in before the end of the season, and it turned out the ThunderSport GB had a meeting at Donington at the end of October.  I'd run my Kawasaki ZXR750 in their Golden Era Superbike class at Mallory in the summer, but the ZXR is out of action having its broken crank replaced.  However, reading the eligibility rules, I noted that GP250s up to 1999 were also eligible, so I could give the TZ a run out! 

So I set to prep-ing the TZ, which hadn't had any attention since the Classic TT.  First job was to fix the broken gearchange linkage, and then change gearing and jetting from those used for the TT, and generally give the bike a bit of a fettle.  All ThunderSport meetings are two-day events, so I loaded the van on Thursday night and set off straight after work on Friday, collecting girlfriend Vanessa from work on the way. Of course, all the good spots in the paddock were gone by the time we got there, and were setting up in the dark, and the very high winds (of which more later).  TT crew stalwart Simon Wilson had also volunteered to help out, and he arrived at a similar time; importantly, he'd brought his powerful cordless drill with him, of which more later.  After battening down all the hatches, we settled down in the van, which Vanessa is converting by stealth into a camper van, and had a few drinks while listening to the wind rattle around outside.

Saturday dawned dry but just as windy.  I took the TZ to scrutineering, and was immediately everyone's friend, as all the scruts gathered round to admire the bike.  A GP250 really is a thing of beauty, and many lament their passing from most road racing.  And the same happened throughout the day as people walked past our awning.  But once scrut'd, we had a job to do - we drilled a large-ish hole (OK, only about 40mm diameter) in the side of the fairing, aligned with the end of the crankshaft, so that we could use the fancy socket-with-a-one-way-clutch in it, that I'd got from the USA, at great expense, as a starting system for the bike.  Instead of having to bump start it, we could now spin up the motor with Simon's drill and the socket.  This was to come in very useful later.

We had a little wait until practice, and then went out on a damp but drying track.  I had a few concerns as we gathered in the collecting area, noting that everyone else seemed to be on full wets, but I was sure my treaded KR 364s would be fine.  I had full wets with me, but it really wasn't wet enough to warrant them, in my opinion, and besides, I didn't want to change wheels just to change them back for the race, by which time it would definitely be dry.

I last rode at Donington about 12 years ago, but I seemed to remember where it went ok.  I wasn't fast, but then, as I'd found at Mallory earlier in the year, ThunderSport GB is a very competitive club.  In the mixed grid of classes I practices with, I was 36th out of 48, with a lap time of 1:29, which was some 8 seconds slower than pole. In case you were wondering, we were using the shorter National circuit, not the full GP circuit with the Melbourne loop.  This put me 19th on the grid for myrace, on row 7, but still with 11 people behind me.  That soon changed as the lights went out - a TZ250 is an awesome machine, but it's no drag racer, and the big 750 fourstrokes I was racing against (I was the only 250 out there) all get off the line a lot quicker and cleaner.  Still, I wasn't last as we all piled into Redgate, and I threaded my way through the usual first corner melee of people running wide and bouncing off each other.  I negotiated this without issue, and then got my head down and actually started racing some people.  It was fun!   As expected, the TZ easily carried a lot of corner speed compared to the 750s, but what also suprised me was how I seemed to make ground on the brakes at the end of the straight.  Of course, I was racing against the back half of the field, as the fast boys were well away, but I had people to race with, so I was happy.  When riding a TZ, you're always expecting the worst, and I did feel the bike holding back a few times when pinned in the upper gears, which made me worry.  I covered the clutch lever with my left hand, just in case (for non-bike riders: if the engine seizes, the back wheel will lock up and probably cause you to crash.  To prevent this, you pull in the clutch - fast!).  And I tried to be smoother, and to not rev the bike so hard, and not only did the problem fade, but I also set my fastest lap!   Thundersport races are longer than most club races, and we did 12 laps, by which time I was 3 seconds behind the chap in front, but less than a second in front of the person behind me.  When the flag came out, I was 20th, out of only 23 finishers.  Still, I'd got that finish which was the main point of being here.

I returned to the awning, which was only just coping in the wind.  In fact, the wind was making a bit of a mess of it.  I'd foolishly not done a plug chop on my in-lap, so couldn't really tell if the jetting was right, but I looked at the plugs anyway, and decided, based on their appearance, and the way the bike had behaved on track, that I should probably go up a jet size.  So I set to, feeling like a proper GP250 racer, while the awning shook and rattled around me.  But when I came to start the bike - it wouldn't rev properly, and ticked over at 4,000rpm.  Curses.  Simon and I took both carbs off again, checked and double checked, and eventually it was ok, without us ever really finding the real reason for the problem.  While troubleshooting this, being able to start the bike with the drill was utterly invaluable.

We had plentyh of time for this, it was getting on for 5pm when we lined up for race two.  I got a decent enough start, and was racing with the same set of people, but on lap four the bike just didn't pull properly in the powerband.  It was still running, but the real power had gone missing, and I know now that on one of these bikes, you stop as soon as you have a problem, so I pulled into the pits.  So that was race 2 done.

When I got back to the awning, we realised that we only had an hour or so of daylight, and it was cold, and the awning was still threatening to become a huge kite. We had a look at a few things - first idea was that the electrical system and/or battery had a problem, and the power-valves weren't working, which would match the symptoms, but a quick test showed that there was a healthy 13.5 volts or more in the system, and the power-valve servos cycled correctly when the system was powered on.  So, in the fading light and gale force wind,  I decided these were not the circumstances under which Simon and I might diagnose and fix the problem, and so made the decision to cut my losses, pack up and come home.  Not a great end to the season, but who turns and runs away...

So now I have two broken race bikes to repair over the winter.  It's a good job I enjoy working on them; this is not sarcasm, as I really do find time in the garage working on bikes very relaxing.  I'll post an update when I find the issue with the TZ.

Jurby Endurance 2017

October 11th, 2017
The Andreas Racing Association has an end of season 4 hour endurance race each year, usually in early October.  I've raced in it a few times, and last year teamed up with my Manx mate Andy Cowie, using his venerable but lovely Yamaha Thundercat 600.  We had such a whale of a time last year that we decided to do it all again this year.  To make things even better, my mate Neil Ronketti had been tempted out of retirement by another longstanding racing mate, Chris Foster, to ride in the same event, on the Darvil Racing SV650 Supertwin. You can read all about Neil's experience in his blog, but the relevant bit for this part of the story is that we combined travel plans, and I enjoyed a good old catch-up and chin wag with Neil and Foz in the car and on the boat.
Riding someone else's bike makes one feel like a bit of a works rider.  You turn up with your leathers and kit, and the bike is there waiting for you.  And that's much how it was for me this time - the bike was all prepared, and all I did was help load it into the van.   I was staying in Ramsey with long-time racing (now retired) mate Keith, and all I had to do was get an early night and get to Andy's for 8:30am on Sunday morning.
Andy's old steelie (racer-speak for a steel-framed 600) really is lovely, and this year, with some fresh paint, it even looks lovelier!
Andy Cowie's Thundercat
Helping us out was John Holt and Graham Wilcock, of Wilcock Consulting, who were sponsoring us for the event.  And we looked quite professional, under the gazebo that Andy bought from B&Q for £57 the evening before (sorry about the trying-to-look-moody face)
Team Wilcock Consulting
Practice was damp, and while everyone knew it was going to dry out, times were definitely 10 seconds or so off a dry pace - pole was a 1:19, and we set a 1:23.  But the times didn't matter anyway, as we lined up in number order.  Despite being told to run for the Le Mans start when the flag *dropped*, pretty much everyone except me set off when it was raised :-)  But it's a 4 hour race, so stealing a few places at the start isn't going to last long.  I enjoyed the ding-dong of the early laps as people sorted themselves out, and the bike was fast and predictable in the mixed conditions.  The track was still damp in places for the first hour, and unusually for Jurby, there wasn't any wind, so it was a good way into the race before the whole track was dry.  Sponsor and pit board man Graham gave me lap times as I passed the start, and I quickly got down to regular 1:16s with the occasional 15 thrown in, before pitting after approx 40 mins (and 31 laps).  We had an uneventful change, and Andy did his first stint, posting consistent laps and getting into regular 17s too.  When we changed for the third rota we were in 9th overall, which was bloody good, I reckon!  And I was having lots of fun - look:
I started my second stint full of enthusiasm, but after 8 laps Dudgie (on the even -older-than-our-bike ZXR750) came past waving at me, and I looked down and saw the rear shock remote reservoir hanging by its hose and flapping around by the swing arm.  I pitted, and John and Andy set to with cable ties.  The timing charts show that we lost 5+ mins here (6:47 lap instead of 1:20 or less), which might have made the difference of a place at the end.  But ifs and buts...  I went back out, and the repair was fine, but the unscheduled stop had dropped us to 15th overall when I rejoined the track, and I could only improve this to 11th before my stint was over.
Andy did his second stint with another set of 16s and 17s (and a few slower, but with endurance racing you can easily lose a couple of seconds in traffic), and then it was time for my third and last stint.  I went out, and after only a lap or two, Derren Slous passed me on the straight on the aforementioned ZXR.  I didn't think about it, but noticed a lap or two later that he hadn't got away by much.  So then I started to try...and I slowly but surely wound him in.  And in the process, I set my fastest times - a few 15s, a 14 and then a 13!   And then I was past Derren!  This was quite a scalp for me. I kept my head down for a lap, but then gave myself a talking to and settled back into a 16 pace, and, sure enough, Derren came back past a few laps later.  But still, it hadn't ended in tears.  I finished our session in what looked like a fairly safe 11th place, and handed back to Andy.  The stop dropped us to 12th, but Andy posted a host of 16s and 17s again and brought the bike home in 11th place overall and 6th in the 600 class.  And, importantly - first Steelie!!!  There was only one other steelie out there, and their fast rider, Dean Osbourne, posted a bunch of 1:10s,so they should have had the beating of us, but they spent 17 mins in the pits early in the race, and that's really difficult to come back from, no matter what speed you have on the track
I've got to the point in my racing where results barely matter - it all comes down to how much fun I had.  And, by that measure, I was stood atop the (fairly crowded!) podium  :-)

That's racing - Take 2

August 30th, 2017

Yesterday was another day that, on the surface, should make one wonder why I bother with this game.

The Classic Superbike race was scheduled for Monday 28th Aug, but the day dawned very foggy, and before the fog lifted the rain arrived. The Clerk of the Course, Gary Thompson, is pretty good at judging the probabilities with the weather, and he cancelled the days racing before midday. So our race would be on the Tuesday. This presented its own problems, as we were booked on the ferry for Tuesday evening; I'd booked this for this very scenario, but still, racing in the afternoon and then stricking camp and loading the vans for a 7:45pm ferry would be a tall order. So I phoned the Steam Packet and managed to push our crossings to the next day (with a combination of freight and passenger ships). There was nothing to do for the rest of the day, so we busied ourselves doing just that.

Race day dawned dry and fog-free, but cold. Still, I knew I wouldn't be cold when racing the ZXR750. Roads closed later than usual, at 11:30, due, I'm told, to the requirements of the local crematoria. But the Junior Classic got away at midday, and then there was a parade lap and we were scheduled for 14:40; there was a slight delay, but the front guys started at 14:50. I'd only qualified 48th (out of 74), so with the bikes starting at 10 second intervals, I had a fair wait until it was my turn (8 minutes, to be precises). But I was soon paddling the bike to the line, the manx flag was waved and I was away down Bray Hill again.

I'm starting to feel quite relaxed riding the TT course, and I'm not sure whether that's a good or bad thing. Still, I hoped to pick up some pace on the 109mph lap I did in practice (which was already the fastest I'd been on this bike), and I also knew that Dave Madsen-Mygdal was starting just one place and 10 seconds behind me; Dave has the record for the most starts on the TT course, and I knew he'd be chasing me down. But I had someone to chase myself - Forest Dunn, #67, on a Suzuki had started in front of me, and as I braked for Quarterbridge I could see him rounding the corner in front, which is always a good sign. I chased him along the very fast early sections of the lap, making ground slowly but surely; this was a good sign itself, as there was no recurence of the fuelling problem we'd experienced at top speed during practice - the last fix we'd found had obviously made the difference. As we went through the twisty Glen Helen section he came noticeably closer, and as I headed up Creg Willys Hill I was on him, and passed easily enough along Cronk-y-Voddy. I got my head down, hitting my marks and references, and felt good. But I wasn't as fast as I thought I was, or I'd provided a tow for him, because as we braked into Parliament Square in Ramsey, some 10 miles later, he came alongside and went back ahead.

This was nothing to worry about, and I was still 8 or 9 seconds ahead of Forest on corrected time (as he'd started 10 seconds ahead of me). I chased him up the mountain, planning when to get back in front, but as we headed onto the Mountain Mile two other bikes came past me - Dave Madsen-Mygdal on his venerable Honda RC30 (5 years older than my 25 year-old Kawasaki) and Michael Russell on another ZXR like me. Michael had caught Dave too, and was quite forceful in getting past Forest at the Veranda. Dave made his way past too on the run to the 33rd, and this meant that if I wanted to learn anything from Dave (which I did), I needed to stay in touch. I got great drive through Kate's Cottage and outbraked Forest into the Creg. But it was to no avail - Dave was just plain faster than me, and crept away, corner by corner. Still, I now had my head down and a clear road in front of me. I flashed past the pits, giving my crew a thumbs up, intended to indicate that the fuelling problem was resolved (which they correctly interpreted) and headed out on lap two.

This lap was much lonelier - I didn't catch anyone, and no one caught me. But it was good all the same, and I managed to keep up my pace (more later). Some 20 minutes later I was back at the pits, this time for a fuel stop - we were halfway through the race. Simon and Alex performed flawlessly - fuel went in, I had a drink, Simon cleaned my visor, and around 30 seconds later I was heading back out again. While stopped, I saw that James Ford was stopped just in front of me, also getting fuel - he'd started 20 seconds in front of me, so I'd also definitely made time on him. I used my fancy pit-lane speed-limiter (which I'd tested in practice) and flicked it off as I crossed the pit lane exit, causing the bike to wheelie enthusiastically, and then we were heading down Bray Hill once more. I took a little care at Quarterbridge, mindful of the fresh tank full of fuel, and then fired the bike towards Union Mills. I've decided that riding the TZ250, which carries so much corner speed, has improved my riding on the big bike - I was changing down less, and carrying more speed everywhere, or so I thought. As I crested the start of the Cronk-y-Voddy straight, I saw a bike in front of me - it was James Ford, and I was winding him in. He was noticeably closer as we entered Kirkmichael, and I knew I'd be on him soon.

Or so I thought. On the exit of Kirkmichael, there was a noticeable vibration from the bike. At first I didn't know what it was, and was actually scared it was something on the cycle parts, which might cause a crash, but it quickly got worse and started to sap engine power - it was an engine problem. As I headed through Bishopscourt it was obvious that I was going to have to retire, and I just hoped to get to Ballaugh, a mile up the road (and which can be accessed from outside the circuit). I only just made it - as I changed down, the engine died, and I coasted in. Damn damn damn.

I contacted my crew, Alex came to get me, we recovered back to the pits after the race, and then headed to the beer tent to drown our sorrows. This might seem like a disaster - two starts and two DNFs ('did not finish'). But racing on the TT course is not like that - I primarily go there to ride the fantastic and challenging circuit, and I'd done plenty of laps in practice. And I'd found good speed too - the first two laps of the race on the 750 had both been at 111mph, which is the fastest I've been on that bike by some margin - last year my fastest lap was 108mph. And the TZ250 had been reliable, with none of the problems from last year, and I'd retired on that for a trivial and stupid reason. Most importantly, we'd had fun as a team, enjoying the camaraderie that comes from living and working together in the paddock. And lastly, it'd been safe - I had no 'moments', and in fact the whole race meeting had been relatively incident-free, with only a couple of people taking a tumble, and no serious injuries.

But I'm still cheesed off, generally, and will be back next year!

Have we found the problem?

August 28th, 2017

After the retirement in the race, and then the drinking and the hangovers, on Sunday morning our attention turned to addressing the ongoing problem with fuel starvation at peak speed and revs on the ZXR750.  By luck I'd met Robbie Sylvester in the beer tent the night before - he'd worked with Slick Bass many times over the years, and knows racing bikes inside out. He told me that the flat slide carbs on the ZXR have microfilters above the float bowls, and these can sometimes get blocked.  I didn't know this, so it gave us another avenue to investigate.  I got myself a good strong cup of tea and started.  Race bikes are usually great to work on, as everything is designed for access, and there's nothing unnecessary in the way. The carbs were soon off, and I cleared space on our bench, turned them upside down and removed the float bowls and floats with needle valves.  The needle valves sit in little brass seats, which located with o-rings in the carb body (Robbie advised that sometimes these o-rings perish and cause problems). I removed the first seat, which came out with its little microfilter sat on top, which is no bigger than your little finger nail. And there, sat on the filter, was a large-ish blob of something that should't be there - some flake of gasket goo or similar: 

So there was the smoking gun - again! We thought we'd found the problem with the loose connection to the fuel pump earlier in the week, so it just goes to show that fault-finding on complex mechanical systems is not straightforward.  We blew everything through with compressed air, swapped the fuel pump anyway, with one supplied by Manx friend Mark Bamford, and put it all back together, and went to the Jurby festival, which is always a good day out.  That evening I took the team to dinner in Ramsey, and then we stood outside in the warm evening air on the Ramsey quayside listening to live music.  Tomorrow (Monday 28th Aug) is our second race day, so let's see what fate brings.

LATE UPDATE: It's Monday morning, and the Island is covered in fog.  Racing is delayed until it lifts.  If it does lift; if not, I guess we'll be racing on Tuesday.