dadof2

I asked at finish but was told times were being kept secret until announced at this evenings do. John Sunter was a bit quicker than Dabill and Brown who were in tern quite a bit quicker than Dougie at Rotten wood, which is only about 10 easy minutes from finish. I did not take accurate note of J Richardson but he was in the ball park as they say. Sunt looked very tired. I suspect Dabill could be overall winner, quick and very good on Obs where I saw him, but I would not rule Dougie out as he may have been even better on Obs. I think Emma Bristow will top ladies as she was quick and generally good on obs but she went a right purler in rotten wood when she clipped a tree branch as did several riders.

I am well aware that putting more oil in weakens the mixture but this is fine so long as the carburation is not too weak, if it is just adjust jetting or needle position. I will tell you a interesting story about this. In the mid 1980s a person I knew used a honda cr250 motocrosser for checking round the sheep in his fields in winter when they were off the fells. He asked me to look at it because it kept "oiling up" plugs and stopping. I had a look, carb settings were fine but plug was wet and black, ie excess petrol. He was running it at 50:1 on Rock oil, honda recommend 20:1 and and therefore presumably supplied the bike jetted for 20:1. By putting less oil in he was actually richening the mixture causing the bike to run cool and blacken the plug, compounded by the slow stop start running in cold weather. I switched the mixture to 20:1 and blanked off some of the radiators. Bike ran fine for a couple of weeks then I got a call "bike is oiling up again". Upon checking the bike I found radiator blanking had been removed and the mixture put to 40:1. He had been to the local honda dealer and mentioned what I had done. Without even looking at the bike the dealer had been adamant that 20:1 was more likely to oil the bike up and blanking of the radiator would cause the bike to overheat and seize. 33:1 too cautious? Well it maybe. I have posted at length on mix ratio previously and am not going to redo that long post here. The facts are, more oil gives more power and less wear, and so long as the oil is of the correct quality and the carburation is set correctly the balance of advantage lies with richer oil mixtures. Many people state (wrongly) disadvantages of more oil such as exhaust clogging and carbon build up, but these problems are the result of poor carburation and or poor quality oils and fuel not rich oil ratios. With a typical top end rebuild costing about £300 + labour I think a bit extra spent on oil is a wise investment. I am not out to scare anyone but based on experience believe the following to be true. If you ratio is 70:1 and the bike revs because the throttle is stuck open it will probably seize as the fuel runs out. If the ratio is 24:1 there is a fair chance the bike will not seize as the fuel runs out. Similar arguments can be applied to 4 stroke lubrication. Most 4 stroke trials bikes will run perfectly well and reliably with semi synthetic 10w40 costing about £2 per litre, changed every 4 trials. On the other hand you can put in motul 300v (£13 per litre) and change it every outing as an insurance against the odd bit of hard riding and to reduce wear in general.

Not that the Scott is ever easy but I just wondered what other riders thoughts are. On the late 70s / early 80s Bultos you had a nice seat to sit on and have a rest on the faster bits or the course and even when legging you could get a decent stride / push whilst seated The monshock TY yams were a bit lower but still had a usable seat. Although the modern bikes are lighter they are much harder to sit down on and get a rest, and nearly impossible to leg when in the seated position, I am 6 ft tall which is nothing exceptional but on both Beta and Gasgas I find it nearly impossible to ride or leg seated, find my legs uncomfortably bent and even catch my knees on the footrests when legging.

Don't want to start an argument on mix ratios but be aware of the following. Motocrossers can manage at 50:1 but they have far bigger radiators and far more coolant capacity than trials bikes. I run my trials bikes at 30 cc oil per litre of petrol which is 33:1 and my crosser at 20:1. By doing so I probably avoided costly engine damage in May this year. I was on a trial when 1/2 way round last lap the engine felt a bit sluggish in 4th gear and stalled unexpectedly. Restarted, engine sounded and ran ok and completed last lap of trial. Following evening I noticed a bit of damp on floor under bike. Turned out to be coolant but no leak obvious. Eventually I found a pinhole in the underside of the hose near the water pump. Something like a thorn or wire barb must have done it. Upon stripping barrel I found the bike had very little coolant left in but barrel and piston were completely unmarked.

Take the exhaust off and turn the engine until piston is at bottom dead centre. Measure the vertical distance from the top edge of the piston to the cylinder head joint, I think it will be about 6.8 cm. Measure the diameter of the piston. Suppose the diameter of the piston is 6.5 cm then 6.5 / 2 =3.25 3.25 x 3.25 = 10.56 capacity in cm3 is 10.56 x 3.14 x 6.8 = 225 cm3 the 3.14 is Pi, just use this number

CC is usually cast into barrel. Note the engine number and ask Beta-uk.com. I have not tried recently but you used to be able to look up your engine / frame number on their website.

http://www.bbc.co.uk/weather/2639510 So the weather forcast for Saturday is good. The going is currently good to soft but likely to deteriorate to heavy after overnight rain. Good luck to all riders and have a great day. I know there has been some whinging about the centenary programme but that won't detract from a fantastic trial which is a credit to the richmond club and all who help make it possible.

Just my opinion but based on many years as engineer / mechanic. 21Nm is about the limit for M8 fasteners into aluminium and I would therefore expect M7 to be about 3/4 of this or 15 to 16 Nm. Torque is a very poor way of setting the clamping force of a fastener because the friction in the threads varies so much. The sps system whereby a small torque is used to take up slack and then the fastener is rotated an additional number of degrees is a far better method.

The hottest parts of a 2 stroke engine are the plug earth electrode, centre electrode, top edge of exhaust port and top edge of piston adjacent to exhaust port. When the engine overheats the aluminium above the exhaust port and the piston in that area expand more than they should do, the first sign of this is a slight drop off in power as the barrel and piston distort, experienced road racers can feel this point and pull the clutch in just before the engine nips up. The oil film fails and the swollen areas of piston and barrel rub hard together and start to melt and weld to each other (look up friction welding on youtube). At this point the aluminium smears about, the engine slows dramatically and may even seize solid. If you look at most older water cooled trials engines the water inlet is at the intake side of the barrel (not a good idea), whereas on more modern engines the cooling water enters directly above the exhaust port in an attempt to combat this localised overheating. If you want to run an engine hard: Make sure cooling system is in good order. Set carb to give slightly rich mixture Put plenty of best quality oil in your fuel.

As above, the "bolts" are allen (hex socket) head screws just above and behind the footrest

Would I be right in thinking the damage is at the near the centre of the top of the exhaust port and that part of the piston that passes over it? If so the cause is almost certainly overheating or possibly a lack of oil, or both. Continual high speed running or mx type use can cause this in addition to the previously mentioned bike on its side with throttle stuck open.

If you really like it buy it. Any trials bike (Mont / Honda perhaps excepted) will be worth less than 1/2 its new price in 2 to 3 years time, so your Jotagas will probably be worth about £2250. Even if the factory went you could probably still get £1500 for it. Parts availability will probably be no worse than any other marque, either still trading or gone.

https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/264624/3._Vehicle_excise_duty_-_administrative_changes.pdf PS don't forget to give you old girl some attention, because if you spend too long on your sherco someone else might pop round and give her a quickie

Just do a search on ebay for automotive or coolant hoses, loads of straight and bent hoses are available. You might have to use copper (plumbing) elbows for some tight bends. I think I got my last hose from ap motorparts.

http://www.bbc.co.uk/weather/2639510 See above, it has improved a bit since I last looked. Nicer for riding than watching probably. So long as its not as bad as 1990 or 1998 or 2008

http://www.motoguzziclub.co.uk/tech/dellorto_tuning_guide.pdf See also Delloreto Uk website for details of specific carburettors and parts. Once you get the engine running roll the bike forwards and slip it into gear, pull the clutch in and open and close the throttle repeatedly, clutch should free off.

Unfortunately looks like its going to be rain most or all of the day.

The smoother running with more teeth on gearbox sprocket is nothing to do with pulling away. As the sprocket rotates the actual diameter of the point at which it contacts the chain varies, the more teeth the sprocket has the less this variation is and hence less vibration. Imagine the vibration you would get with square wheels with 4 large flats compared to a round heel which has an infinitely large number of infinitely small flats. This is why smaller road bikes run 428 chains, there are more teeth for a given diameter. The handlebar operated enrichment is a common mod for beach / sand racing, particularly important for slowing down from high speed with throttle closed (no oil getting to engine) or when running at high speed with partial throttle which tends to cause weak running with insufficient oil. When defending long hills on a trials, enduro or mx bike you should periodically blip the throttle to give the engine a bit of oil. should say descending not defending

Just out of curiosity, why buy a lively lighweight bike then stick a weight on it? Have you considered a smaller bore carb or slow / variable rate throttle?

Going up one tooth on gearbox will give near same effect as JR Sunts suggestion of going down 3 on the rear. Going up on gearbox sprocket will also make bike run smoother. I am not familiar with your bike, if there is room and a bit of slack in the chain you may be able to go up 2t on gearbox which would be a lot easier than changing chain and rear sprocket as well. My preference is for much richer oil mixtures than 80:1. I don't know how much riding you have done but with a bit of experience you can tell when your bike is getting a bit hot, usually power starts to fall off and it may start pinking. Handlebar control of cold start enrichment is easy, cheap way of countering this.

Water in fuel, "balls" of water rolling about in float bowl. Is you bike a gas gas or Beta rev 3?

To make a useful difference to gearing for road use would need a change of 25 to 30%. This would probably ruin it for trials. If thebike feels low geared for trials go up 1 tooth on the gearbox and / or down 3 or 4 on the rear wheel. Fit a handlebar lever to operate your cold start enrichment so you can give it a bit of extra fuel to oil and cool the engine, especially on the overrun or high throttle.

Joke name for mature male cyclists in UK is MAMIL, stands for middle aged men in lycra.

From the supplementary scott regs "8. UNAUTHORISED ASSISTANCE: A driver should not be accompanied during any part of the Trial by any other person or vehicles with the object of obtaining mechanical assistance therefrom. A driver shall not assist any other driver in any manner which might be deemed by the Clerk of the Course to be pre-arranged or organised. "

Youtube viewing is possibly not a true guide to popularity -, for me and some others I have spoken to its something they browse when there is nothing better to do, just a case of looking at things because you are a it curious and often one video leads to another which you would normally never have dreamt of looking at. At the risk of some sarcasm here is my list of recent viewing, about the last 4 days, oddly no trials at all. Clarkson - raid on St Nazaire Japanese precision walking competition - over 6m hits Chinese pink womens army marching North Korean marching worlds top ten fighter aircraft The duet from Mozarts marriage of figaro Suo gan El duguello Green leaves of summer All over the world El paso - Marty robbins ballad Streets of Laredo Snipers - the movies for men documentary contortionist - flexible woman The ridge - but only as it was on TC I did not like it A 9 year old opera singer on the dutch got talent.