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"what it means is that you can run leaner fuel / oil mix to effectively burn more fuel unlocking power from the engine whilst still maintaining protection and minimalising engine wear."
That statement is simply just not fact.
Engines make more powrer at 20:1 fuel:oil than they do at 50:1 - ask any professional tuner.
More oil in the fuel = less wear
Moving from a ratio of 25:1 to 50:1 increases wear by a factor of 200 to 300%.
Cheers
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How do you know its overheating?
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http://www.shell.com.au/home/content/aus/products_services/on_the_road/oils_lubricants/advance/product_range/racing/
Have a look at the above link and the mix ratios. These oils and castrol as well have a significant additive packages that won't burn off in normal trials usage. Running them at lean ratios compensates for this to some extent as it lessens the amount of additive.
Why buy an expensive oil for hard use lubrication then throw much, maybe all of that benefit away by lean oil to fuel ratios?
Cheers
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http://www.clarkforest.com/shop/chainsaw/2-stroke-oils/oregon-2-stroke-oil-5-litres
If you are looking for decent oil at a good price try the above - it meets the latest/ highest specs as regards lubrication and cleanliness. Also when you see the hammer these small two strokes get day after day with little wear you know its a good oil.
As for Castrol A747 - yes a superb lubricant but as it is based on castor you probably should use it within a day or two of mixing - not leave until next weekend.
Cheers
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Ask around at nearby trials and local trials shop and see if you can find some riders to practice with.
Cheers
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I have signed the petition but wish to say more:
I find it offensive that the government does not do much more to help things like the air ambulance and fell rescue services where volunteers give so much time and effort. Yet at the same time it subsidises bus and rail companies whoses bosses enjoy profits and bonuses for providing an often poor level of service.
Its the same as the "arts" they expect public funding so a few prats can dress up and ponce about on stage. Why does the government not subsidise our chosen hobby / sport?
Cheers
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I was actually joking when I suggested marking on style. Its 36 & 1/2 years since I first observed. It was a 2 lap open to centre trial with about 120 riders and I was marking two sections with just over a bike lengths rest between the ends of the first and the begins of the second. On that day thefore I gave 480 scores (less a few retirements. All riders (novice, intermediate & expert) tackled the same route. Only about 6 times did riders ask for scores, all where there was some near judgement made. The only time I had an issue was when a mate of the potential winner shouted "what was that" after the potential winner had struggled (and failed briefly and intermittently) to keep the bike moving out up a muddy rut out of the river. I shouted back (across the gulley) 5 at which point the mate started to argue. I said it does not matter anyway he fived lower down on the step. At this point the potential winner nodded his head in acknowledgement and rode off.
I observed the same open to centre trial (different section) recently. This section was a climb up a rubble filled gulley with different entry points for different categories of rider. There was just over 80 riders doing 2 laps.(so say 160+ scores) I was probably asked for scores in 20 to 30 % of the attemps, about 10 cases of mild disagreement and 2 or 3 cases, what ~I would call pretty displeased rider disagreement.
Both trials under no stop rules. The difference - back in the 1970 pretty well all stops were strictly and correctly penalised with a 5 and the riders were used to it. Now far to many seem to think there is some "sort of stop" that should not be penalised. My own view is that a clear stop or momentary drop back with a foot down is a 5 but a slight hetitation with feet up such as Fry at the bottom of the bank or Wiggy bouncing up and down at the top should be a 0.
Cheers
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It will improve performance accross the range. A two stroke needs less advance at higher RPM (unlike a 4 stroke)
I suggest you have a look at the PVL home page (difficult to find - I will post link tonight) and read two stroke tuning by A Graham Bell.
I would be inclined to give the programable digital ignition serious consideration.
Cheers
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In the strictest interpretation of the no stop rule "the front wheel spindle must maintain forward motion at all times" I would have give both Wigg & Fry a 5. Fry stopped at the bottom of the slope, you can see his bars recoil.
If I were actually observing (as I do occasionally) I would probably have given cleans.
My real dislike is when riders in no stop trials expect to put a foot down, pull the bike back and re attempt the step or whatever and expect only a one.
I have a solution - why not mark on overall style instead, like they do on strictly come dancing or dancing on ice. If you think the riders effort is good and he gets up the section its a 0, if he struggles and messes about but still makes it , give a 3. If he stops and has to drag the bike about its a 5 and if the rider is a right tosser and not dressed properly its a 10!
Cheers
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Have a good look at the hose, where it runs, where it has up loops in it, and is the bleed nipple at the highest point of the caliper. My mate had this problem on his gas gas and taking it off the bike and hanging it up overnight cured it, this allowed all the air to get back to the master cyinder.
Check the lever adjustment has not been tightened in too far or the fill hole in base of master cylinder may not be uncovering properly.
Another problem could be corrosion (like a white powder) behind the slave cylinder seals, this makes the pistons retract more from the disc than they should. You usually have to split the caliper to get the seal grooves clean, first use a piece of hooked wire then polish out with wire wool pressed into groove with screwdriver tip or similar.
Cheers
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Full length gaiters are the answer, seals last forever and the gaiters protect the stantions from damage if you drop the bike in rocks - however as a previous poster says probably a bit gay or flat cappish for the stop and hop brigade.
A good tip is to left the dust boot and wrap a piece of sponge soaked in thick oil round the stantion then replace dust boot. This stops most dirt getting at the seal and you just clean or replace the sponge every few weeks.
Cheers
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Hi there Mattylad, just with regards to your comments about modern riding techniques. Smalling 123 is located in Yorkshire and the chances are the bulto if used in trials at all will be non stop event. I don't do many trials these days but I have nover come across a trial for classic twinshocks like the bult run under WTC type stop & hop rules.
Cheers
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Unless you have easy access to a scope I would just check the CDI charging coil on the stator with a digital multimeter first. 9 times out of 10 this is the cause of Beta stator / ignition failure. As well as resitance quoted previously I would expect this coil to have an output of 20 to 30 volts AC if flywheel is rotated at about 450 to 650 RPM with a drill. If you have a friend with a running Beta with same ignition system check that to see what it should be.
Regarding scoping the CDI theres not much you can do without very specialised pulse generating equipoment and manufacturers info. The one thing you can check is the CDI to coil output ONCE you know your stator output is OK and therefore charging the CDI, Spin the engine with drill and the CDI to coil output probably starts at 350 volts dropping to near 0 volts over 200 to 250 miliiseconds. Again doing the test on a known good bike would give you the exact voltage curve you should see on the scope.
A 4 channel scope with trigger so you can measure A V in and A V out simultaneously is most likely to give really useful data.
Cheers
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As the rpm drops, the voltage / current to the cdi drops so if there is a fault with the cdi charging coil meaning it is giving less than its intended output this will be more prevalent at low revs. Trigger coils usually work or they don't but they can show the same symptoms.
I would expect the cdi charging coil to have a resistance of 50 to 250 ohms (unfortunately BETA in UK don't publish the exact values) Trigger coil resitance can be similar or even up to 1250 ohms. Digital multimeter needed
The problem with the above is that resistance and generating capacity vary with temperature. The best way to check is with an oscilloscope whilst rotating the engine with a power drill. Any deviatin from a smoothe / expected waveform indicates a defect.
It would be worth taking the barrel off to check the piston has not scuffed slightly and nipped a ring, this alo gives symptoms you describe.
Cheers
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I had a number of Sherpas, 250 and 325 from 1970 to 1980. All the post 1975 models ran beautifully smoothly right from tick over to full revs. They had plenty of power and ran smoother than ossas, yams, Gas Gas, betas and other reed valve bikes I have owned. I know reeds give more power than piston porting but I would be happy on a non reed bulto today, they would pull from nothing in 3rd on the steepest hill.
I also had one of the last non reed 1982 Maico motocrossers. On a dry day the 83 bikes with reed valves (honda particularly) could see it off up the start straight. But when it came to finding grip out of slow corners or grassy cambers in wet conditions it would leave the reed bikes standing.
I would be inclined not to fit a reed to a bulto. At least until you had tried one out and compared it to a properly running standard non reed verion.
Cheers
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I am slightly hesitant to post on the subject of premix oil because there are many different, often strongly held opinions.
I have had excellent low engine wear from old fashined mineral oils like castrol TT, yet significantly faster wear of both bore and bearings using supposedly far superior modern synthetics.
You will probably find the standard recomendation for fully synthetic in a gas gas is 1.5% which is 67:1 or 75cc to 5 litre fuel.
The recommendation for mineral oil is 4% which is 25:1.
My preference is for good quality semi synthetic like Shell advance VSX 2 at 30:1.(167 cc oil to 5 litres petrol)
Of the fully synthetics some consider Motul 2T 710 or Castrol TTS to be the best lubricant.
Cheers
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Make an extra wide / thick gasket froim cereal packet, paint both sides with blue hylomar and allow to nearly dry before fitting.
Is is a faulty gasket or distorted case that is causing your prrsnt leak?
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Heat it till the soap just chars, repeat the heating after bending is finished to stress relieve / anneal it.
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Trials is a bit like Highlander (Sean Connery and the bloke who was in Greaysoke) "there can be only one" and at the moment that one is Bou.
Top level WTC is so far from ordinary off road riding that its going to turn more and more off, its not just the event costs, its the years of unpaid or low paid practice that is needed to get anywhere near the standard required.
The factories are not selling enough bikes to pay works riders.
Perhaps trial is fundamentially an amature sport and always will be.
Cheers
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Following is a bit messy but worth a try. Remove the carb and tank from the bike, then with the float bowl off turn the fuel tap on and see at what float position / height the flow into the carb actually shuts off. Also check the floats are not catching any part of the bowl or jets that is resricting their movement.
Cheers
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Common cause of corrosion in stators is use of silicone sealant on the cover joint. Many types of sealant give off acetic acid fumes as they cure / harden. This creates a highly corrosive acidic vapour inside the cover.
Use something like Hylosil that contains corrosion inhibitors instead of acid.
Cheers
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Perhaps if a good number of forum members write to their MPs reminding them that he had pledged to stop further EU regulation.
Cheers
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Many years ago (when bikes were heavier than today) some riders used to carry a long car fan belt. This could be looped round some part of the bike then back through itself to form a lifting handle.
Typical use were through front weel rrim so you could get both feet on firm ground to drag bike pot of a boggy ditch or round swinging arm to lift back end out of bogs.
Cheers
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Following may be worth a try:
Remove the springs and fully compress the forks then fill with oil to within 100 or 110mm of top of fork tube. re assemble and try. You could go down to 80 or 90mm free space above oil and see if that helps.
Cheers
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See if you can find someone with a PICOscope who knows a bit about / has an interest in motorcycles. If someone has a PICOscope chances are they will be able to apply car component testing practice to your ignition system quite easily. PICOscopes are common in car engine management diagnostics and they are very useful for detecting faults causing intermittent symptoms. If you contact http://www.picotech.com/ they should be able to tell you of someone in your area.
If you only have a multimeter check the coil (all coils) resistances and compae them with known good ones.
Cheers
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