trapezeartist

Nigel, I'm afraid I have totally failed to understand your metaphor(s).

Sounds like my story too. Whereabouts in Somerset?

Item location: Middlesbrough Seller location: Cloud Cuckoo Land!

Every "mass market engine" starts off as a niche market engine. If the niche engine proves to be what the buyers want, it becomes a mass market engine. In the world of high volume cars, the current trend is to small capacity, turbocharged direct injection (stratified charge) petrol engines. My present car has just such an engine which has the same fuel economy and performance as my previous diesel, along with far better refinement and presumably less NOx and particulate emissions. No engine in a trials bike is "mass market". If a side-valve engine proved to perform better in this unique application, the specialist engine manufacturer could readily develop such an engine at sensible cost. I would like to think that trials bike customers would make a more rational buying decision than the average car buyer, and would happily accept an engine that shares certain characteristics with an Austin 7 and a Ford Pop in order to get the performance benefit. It would still require a degree of marketing on the part of the bike manufacturers though.

I signed.

Yup, I think we're all with you there.

The reed valve appears to allow the crankcase to pressurise, but relieves a depression. Could the reed valve be something to do with the oil system. If you allow the crankcase to build up pressure, that pressure could be used to scavenge oil back to the tank (gearbox?) without needing a scavenge pump. I'm not familiar with that Honda engine but I think I remember someone saying the same oil lubricates engine and gearbox.

That is a really good idea. Years ago I made a torx key out of an Allen key with a bit of judicious grinding, in the days before torx bits became readily available.

So not everything is bigger in America, then.

I don't understand this either. Clearly there is a lot of pumping going on in the crankcase of a single cyclinder 4 stroke. A volume equivalent to the swept volume needs to be pumped in and out of the breather every stroke. If the breather isn't big enough there will be a fluctuating pressure in the crankcase. Adding a one-way valve simply means that the breather flow in one direction is enhanced. I can see this being a benefit for stopping the engine pumping oily fumes out through the breather, but I don't see what it does for engine braking.

Buck is slang for a dollar. A quart is an archaic measure of liquid quantity, along the lines of furlongs, firkins, poles and perches.

Any good?

If you suspect the tapers are not as good as they should be, lap them together before finally re-assembling. Leave out the key, smear som grinding paste on the shaft taper and then oscillate the flywheel on the shaft. After a few seconds of that you can wipe the paste off and inspect both tapers. If they're a nice even grey, the job is done so just get on and assemble. If not, put more grinding paste and work away until you have got to near 100% contact between the two tapers.

Is the 4x4 on the short wheelbase or long one?

Countyist! Drifting off the subject slightly, but if world-class or even national results could show us the hierarchy of the "best for an expert" trials bikes, I still suspect that the hierarchy of the "best for a clubman" trials bikes might be very different.

Citroen Berlingo or Peugeot Partner seem to be the obvious choices for a bike-carrying van. However a lot of the older/cheaper ones are in an awful state as they seem to appeal to builders. I've noticed a few nice Renault Kangoos advertised which look to be in much cleaner condition. Perhaps they appeal more to flower shops and the like. Has anyone used a Kangoo? Does a bike (just one) fit in OK?

That may or may not be true. But if Tony Bou won a trial this weekend with a banana stuck in his left ear, we'd all have a banana in our ear next week.

What's the engine?

Wakka, it's just a wild guess but I think he might be in Dumfries.

Purchase valve cores? I thought you just had to pick them up off the floor at the local tyre fitters.

I'm pretty much a newbie too, and I've yet to buy my first bike. Some people advised a 125 to start out and others advised a 250. The one consistent piece of advice was to avoid anything over 250. I rode a 200 Beta at a trials experience day and it was entirely manageable. I could imagine that with a few more goes I might occasionally be wanting a bit more oomph, so I will be buying a 250 almost certainly. If the right 200 came along I would be happy with that, but it seems unlikely because they're up on the same shelf with hen's teeth and rocking-horse s**t.

The double gearlever looks a bit unnecessary. And the humungous rear sprocket might be vulnerable. Surely there's another way to achieve suitable gearing.

This is something that has really surprised on me return to trials: the obsession with bling. Sticker kits, wheelrim stickers, colour-anodised bits and pieces, fork protectors, frame protectors......... For god's sake! It's going to get covered in mud and thrown in amongst rocks.

Mud, mud, glorious mud! There's nothing like mud for cooling the blood.

I thought Kickstart was recorded at Easton Neston (Lord Hesketh's estate).