just thinking about this now, the knock is pre-detonation, this might be being caused by excessive heat, check your impeller is turning and that the fan is working on the thermostat. its the 15 mins thing thats got me away from fuel, thats too long really.
fuel starvation, or water in the petrol tank. clean the carb (take all the jets out and blow through) while the carb is off remove the fuel tap and check the filter (drain the tank first!)
i've lost count of the amount of woodruff keys i have replaced over the years.
last one was on a Honda CRF450 enduro bike last year, it had already been to two shops, £1700 spent trying to get running, Half an hour later it was running lovely, bloke came to pick it up, i wasnt there, didn't pay a penny, i hope it threw a rod and ripped his gonads off in the process.
A rich bog is where Richard Branson dumps......................
Colder air is denser , more oxygen, leaner mixture.
Your right altitude means thinner air.
If your bike feels like the choke is on its too rich, if you open the throttle and it makes induction noise but loses power this is usually over lean, in this case putting the choke on makes it better.
Jetting is a dark art, and nigh on impossible to over the internet.
if the engine is out, take the whole thing down to a car garage and get someone to spin it off with an air gun, no need for a tool. Or, i don't suppose you have tried a Yamaha dealer have you, from memory there were only 3 sizes on all yams that age anyway.
And what kind of High tuned sensitive machine do you ride? Adjusting your fuel mixture because it's a bit chilly?
Its a two stroke EVO not a Diesel Montesa, you obviously know bugger all about engine performance so i would shut up, and I do mean Celsius.
Ham2, carb icing is great isn't it? I remember having a 300 KTM that carb iced in winter, what a pig to ride and it got through loads of fuel, not fun trail riding in he dales!
no different to riding in stream sections for the cooling down aspect.
Running in very cold conditions makes engines run leaner, if possible you should richen the mixture and/or jetting for cold conditions, or stay inside where its nice and warm and forget about silly Trials bikes until the temperature outside gets to at least 14 degrees.
seriously, put a chain on it and ride the bike to check the gearbox before going any further, if the chain came off and got stuck behind the sprocket this is what causes the damage. Ride it every gear for a bit, if something has happened to the gearbox it will be obvious.
sorry say that there's every possibility you have broken the gearbox, i have done a couple of Rev3's from this era and it takes teeth off the gears, pretty sure that both the ones i did needed main shaft and a gear (2nd if i remember rightly)
Best bet is to put chain on and rock the rear wheel backwards and forwards whist trying the gearbox, once this is done try flushing the gearbox with some diesel, then drain again, if there are any teeth floating about they will attach to the drain bung.
cant help but think that you have missed the point completely. The rules apply to all, the majority are club riders, top flight are the minority, its how it affects you on a Sunday that matters. Club trials aint a spectator sport, personally I want to ride my bike, not sit in queue's, longer than I actually ride for. I don't want to watch some Herbert bounce his bike around for 5 minuets 3 feet into a section, watch him drop 3 doing so and then fail the obstacle anyway. (local trial, only local one running stop allowed) when he should have just ridden in, picked his line, failed the obstacle and moved on.
Top flight competition on the other hand should be a spectator sport, and the paying public want a show, bounce around all you want, ride backwards, the whole shebang,
Non stop gets a trial moving, flowing, you have to pick your line carefully, and ride accordingly
All that said, clubs will apply whatever rules they want, just look at the results and count the attendance, vote with you feet/tyres as you see fit.
Beta 250, better bike to start on by far, there are loads of very high minded opinions about"what's the best bike" but this was best summed up by a guy i rode with a few years ago, "a Beta will compliment a riders style without having to modify that style drastically"
This guy had gone though 2 Shercos a 200 and a 290, bought a 250 beta and his results jumped 10 places into the top 8 everywhere. There's nothing like results to tell you how a good a bike is.
Impact Air gun, by the time you've bought a clutch basket and a holding tool you could have got a small second hand compressor and a second hand air gun.
New Member Returning To Trials.
in Introduce Yourself
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I would welcome some titanium, I seem to be lugging around several dozen pork pies!