Thursday, 24 April 2008

Irritating Minutiae?

Or important details?!

Since our outing at Snetterton, some things have happened...

1) My missus finally hit the roof with the prolonged head-build on the dining room table. Much cooking and grovelling to be done this evening.
2) I have dremelled the inlet manifolds such that they line up with the (enlarged?) inlet tracts in the head
3) I received from Rog (you lovely, lovely man!) some shims of 1.6 - 2.0mm to sit under the lower cups under the valve springs. These allow the installed height to be as per the R/D spec. Effectively this preloads the valve springs. I'd think that failure to appreciate/rectify this would result in valve float at high revs.
4) Ordered some spangly new oil lines.

So last night (having promised that the head would be off the table and atop the motor that evening) I got my shims on, and just before putting the springs & collets etc together, I thought I'd make sure that at full lift the collets & top spring retainer don't foul the valve guide seal.

Guess what?? There's contact... I can still turn the cam, but I wanted about 1mm clearance. The spec sheet recommends 50 thou, but I reckon 40 would do. Anyway, its a no go.

I tried tapping the seals on, taking them off, grease on the guide, etc etc. No f'cking joy. This would surely be asking to drop a valve...

The seals are pattern parts. I have now ordered genuine Yamaha parts, so we'll see if these are any neater... Failing that, it will mean (god no!) machining the already shortened guides.

Its a puzzle, as the motor ran with this cam. Although not these springs collets and retainers... I tell you what, building this motor is fast becoming a pain!


Thursday, 17 April 2008

SuperMono Championship (Rounds 1 & 2 - Snetterton)

Friday 11 - Sunday 13 April 2008

Friday practice was the low point of an otherwise brilliant weekend. Having been fairly confident that Steve Lakes bike, TZR250 chassis and SRX640 engine, would be reliable for the whole weekend Andy promptly dumped it at Russell’s chicane. I think he had a genuine excuse as the tyres were not brilliant (road-biased), it was on the first lap (cold tyres) and although not actually raining, it was damp. Andy suffered minor, but I expect painful, injuries – hip and hands bearing the brunt of the impact. Unfortunately his long serving Arai splat-hat also took quite a battering as he slid face down along the track.

Having walked from the pit-lane over to the scene-of-the-crime, thinking that Andy might need a hand pushing the bike back to our camp, I saw him being whisked off towards the scrutineers shed. This walk across the Snetterton paddock was to be another feature of the weekend. When I finally got there the hobbling Andy and myself were directed towards the Senior Scrutineer as he wanted “to have a word with us”. He then produced a pink sheet that listed all the following faults likely to keep us off the grid the following day (this was in addition to what they might find during the real scrutineering – Merde!). Both fuel and oil tank (Monza) caps needed wire locking shut, steering lock was too limited, no lower rear chain guard, fairing oil trap too small, and a few other minor problems! It took us several hours to rectify all the problems as best we could, and we were still not certain that the bike would still be eligible. We also replaced the broken kill switch, which was to cause much grief later on.

Saturday morning was bright and breezy as we pushed the re-built bike to scrutineering. Much to our surprise the very helpful Senior Marshall gave us the green light. We walked back ready for the first practice. This was when the kill switch came back to haunt us. After only two laps Andy began suffering an intermittent electrical fault, only rectified by judicious waggling the kill switch with his thumb. This couldn't go on forever, and after a few threatening intermittant faults, eventually the bike stopped all together. This may have been a blessing in disguise as we also uncovered a few issues with the front brakes. The electrical fault was easily solved and a new brake lever bolt was installed. The next problem surfaced during Sunday practice; the re-jigged front brake locked itself on. Being stuck, unable to move, with racers passing either side at full-chat, must have been a brown-pants moment. Enter stage right the recovery van, again! Upon its return the brakes were finally sorted by replacing the master cylinder (Thanks Dave) and using new, not sludge brown, brake fluid. After all the traumas we did the only sensible thing and retired to the pub. We had a good laugh with Ash, Nick, Sam and Liam, mostly arsing about with our new, sponsor provided, Buffs, drinking beer and eating chips.

The race on Sunday, by comparison to the previous days disaster, was slightly anti-climactic as everything worked more or less as it should - no crashes, no breakdowns. Andy finished, albeit in a foul mood. The borrowed bike was still rather underpowered compared to the rest of the field (sixteenth out of twenty six starters is OK, isn’t it?). Perhaps our rather poor showing could also be attributed to a lack of confidence after a fairly fraught weekend. However, we are supremely grateful to Steve for his loaning us the bike. Thanks, you're a gent!
And very sorry for smashing it up! We promise it will be returned (more or less) as we got it!
When we next come out to play we should have the ‘real deal’ bike ready, and I think we will both be disappointed if times/positions don’t improve.
See you at Brand’s………… July!

Tuesday, 8 April 2008

Down... But Not Out!

A team without a bike is like a Friday night without a kebab. Rubbish!
The Tigcraft is still in need of a bit more attention; the chilli sauce, if you will. However, the motor's in its final position, the controls are getting there, and some parts are winging there way in from far off lands with a good exchange rate. Not having the bike for this first Supermono weekend at Snetterton makes us Glum and Glummer; however our good chum SteveL has stepped into the breach to lend us his trusty track iron forthe weekend.


Moreover, he put a fair bit of graft in last week to get it back in one piece. Thanks a lot Steve, you're a gent. We are no longer glum, and Boyd will make you a cup of tea and a fresh cream canape over the weekend in the paddock.

To get it race legal, we needed only number boards, a bit of lockwiring, some attention to the fairing, a kill switch, and that's about it. We've changed the sprocket for Snetterton's long straights.

Like our Goode mate John, its a TZR250 chassis, with a 640 Yamaha motor. Its not the easiest to access the motor, so I am glad we didn't have to do any real work.

Steve reckons it was raced about 10 years ago in this class. Either way its a step up for me. Its got an ally tank (so it must be good), and I am finally dragged kicking and screaming into the 1980s with a monoshock rear end...

With a little paint and some stickers we reckon she looks so good that we've decided on just that colour for the Tigcraft when she finally graces a circuit near you (sometime!)

See you at Snetterton? We're #16, look for a non-beutiful ex-ambulance in the padoock. Boyd will be serving the cream teas in a french maid outfit...