goudrons

Bearings have a code etched on the edge of the race, so it might be worth removing yours and checking the numbers, then source a quality replacement from a bearing supplier. I'm only guessing, but it should be something like 32004 (which measures 20mm ID x 42mm OD x 15m Width) or perhaps a 32005. If you can't get the code off them, try measuring them, then google the measurements. Other than that try one of the Montesa specialists like Sandifords or H&D Racing.

The 4 pots don't like it when the pads wear down, I think if the pistons have to come out that far, they don't come out straight and that's when you get trouble with them jamming up. I've had one in the past leak, the two halves seemed to have come loose and rocked against each other, squeezing the fluid out of the joint. Must have been like that a while as no matter how tight, they wouldn't pull up and seal. I ended up getting the two inner surfaces skimmed flat and fitting a new O ring. A big one of these http://www.ebay.co.uk/itm/1-x-100ML-LARGE-DISPOSABLE-SYRINGE-STERILE-/150616229523?pt=UK_HomeGarden_Garden_PlantsSeedsBulbs_JN&hash=item23116d4693 and a bit of tubing attached can be used to back bleed the brake from the nipple. Just connect it to the nipple, open it and flush the fluid back through the system.

Keep finding these Golden Trials Tyres listed http://www.bosioffroad.it/shop/index.php?page=shop.product_details&flypage=flypage.tpl&product_id=14035&category_id=15&option=com_virtuemart&Itemid=58 http://www.haventrialsport.co.uk/product_info.php/golden-tyre-pair-trials-pair-tyres-p-210942 I'm an IRC man myself, but always willing to try something new. Anyone using them? What do you make on them?

If there's too much float (cracking/knocking/creaking brake with a lot of movement when you apply it), the little top hats that fit between the bolts and the disc can be replaced. They are around £2 each and you need 4, though the bolts can be a pain to remove as they are threadlocked in. (Funny my 07 has gone like this, and I'm a Bexleyheath member?? Must be something in that stream at Burwash!)

Not fitted them myself, but a mate bought a pair (then another) and sent them all back, though not the TY, but Ossa. They were far too short, when checked if they were right, he was told to fit spacers, so there was 3 inches of travel lost! The coiling of the springs were far too tight, so they locked up with hardly any travel, also the progressive coiling was just an inch and a half of tighter coiling at one end, and as the coiling was already tight enough, it hardly seemed worth it. Don't know if these were just a one off problem with that set, but the next were the same. I had a good look at them and I didn't consider them worth it, but that's just my opinion. I'd have a word with JC of TYtrials, see what he suggests as replacements.

Not cheap and it still uses the original HT coil. I think this is a Motoplat system, and from what I've read on another post the fly is a little light. http://www.francetrialclassic.com/en/ignition/2525-montesa-cota-123-172-200-electronic-ignition.html http://www.trialscentral.com/forums/topic/42896-any-one-using-electronic-ignition-kits-from-france-classic-trial/

Make sure they finish the ports correctly, they need chamfering or it'll knock it's B*****ks off!

Someones put it more eloquently than me, "An engine makes the least torque at idle and low rpm, the engine torque is too small to overcome the bike's inertia, and it stalls. If you have a flywheel, the stored momentum augments the engine's torque allowing you to use a lower rpm starting-off. Without a flywheel you'd need a higher idle speed, or constantly need to start-off at a higher rpm in order to raise the engine torque output enough to avoid stalling the engine."

Quite often the spark from electronic ignitions looks weak, they can tend to be almost white or very dark blue in colour, it doesn't mean they aren't working. You need a darken room to really see them, or try your hand, you'll soon now if it's kicking out enough! I'd have thought the lighter fly would make it easier to stall as it's the flywheel weight that keeps the motor turning between firings. Too light and it would not have the inertia to keep running steadily. It's very noticeable on engines with light flywheels that they don't idle well and seldom run slowly, when's the last time you heard a F1 car idle a 750 rpm? Have you weighed the stock and replacements? How much difference is there? If there is, you could try adding it to the replacement and see if it makes a difference, you can often bolt a flat weight on to the flywheel.

Headlight? Not seen one of them on a TY for a while, most have had the lighting removed long ago and are ran a pure twin shock trials bike. Over here in the UK we can just use them on the road with just a horn, but it's only for daylight use. There are two coils on the stator, a source for the ignition and a lighting coil for err lights. I'm unsure why one would interfere with the other unless there's a bad earth that both these coils share (earth from the stator to frame?) or they meet via some ignition switch on the handlebars. But I'm not an expert on these lighting set ups (I presume it's direct AC without battery with some sort of diode to limit the output??), my TY175 had all the lighting binned long ago, now it runs an electronic ignition, no lights, points, condensers, it's bliss! So all I can suggest is checking all the earths and connection and perhaps the resistance and output of each coil on the stator plate (need to find out what these should be) There are electronic kits available for the 250 with and without a lighting coil. This one has a lighting coil. http://www.electrexworld.co.uk/acatalog/STK-402L.html It may be it's just a coincidence the headlight, and it's the carb still, might have ran lean on your run to the stop sign and as you've messed with the switches and it's idled a while, it's richened back up?? Have you check it has the correct jets? Float height correct? Pulled the plug to check the colour? Is it dragging rust or ***** from the tank and blocking the jets? Failure to pick up and rev off idle can usually be traced to a blocked pilot jet.

Ok, first this isn't your carb, but the process is very similar. http://www.trialscen...&attach_id=6019 Remove the float bowl gasket first. Follow pics 1 and 2 so the floats just rest on the inlet valve but does not squash the little needle all the way in, just so it shuts the fuel off. Then measure the gap between the two red lines, but you must measure from the float bowls sealing surface (on the carb body) with the gasket removed to the top of the floats. The height should be 24mm (+/- 1mm) The tab that actuates the inlet needle will bend, if the height is incorrectly set, this needs gentle pressure to alter it until the required height is achieved. This may also help in identifying a worn inlet valve/needle. http://www.tytrials....-Twinshock.html

Sounds like the inlet valve to the float bowl is sticking and the float isn't shutting the fuel off when it should as the valve should stop the fuel even if the tap (petcock) is knackered and won't shut off. Has the bike been stood for a while? Gummed up old fuel can cause this, I always drain the fuel out after use. Float height too high? And it's not shutting off before the float bowl is full. Or is there rust in the tank? And it's jamming the valve open. (I can't remember which had the alloy tanks?) Take the carb off, strip it and clean it well and reset the float height. It might be worth fitting an inline fuel filter between the tank and carb as well, they are very cheap. Check and sort the tank out, if it's needed there are cleaners and sealants that can sort out a tank if it's not totally rotted.

Not sure if that's the right one, but I rebuilt an old Beta Zero a few years ago and some of the electrics for the fan were missing. I went to Maplins and explained that I needed to rectify the AC produced from the gen (can't remember the output of the gen, but I did tell them) to DC at 12 volts. They sold me something very similar and it worked a treat. So it might be worth getting the gen output and asking in Maplins or other electronics shop.

These can cause the engine to run lean. Don't Boyesen suggest upping the jets in the instructions??

http://www.trialscentral.com/forums/topic/42690-engine-paint/

I've had my Ty in the back of my old mans Pug Partner, that's the same as the Berlingo. You sort of angle it in when the back seats are out. The Hdi engines can be a little problematic, though many do mega mileage without too much agro, think some models have the multiplex wiring that can give trouble, older 1.9D's good, though cooling is suspect, 1.4 petrol is pretty hardy, not too powerful, but should hit a lower tax band.

Most old twinshocks were what were considered parts bin specials, that is, manufacturers used existing parts off other bikes to make a trials bike. Most were based of trail type bikes and shared a lot of their parts, particularly the Japanese ones, though go back a little further and you'll find they were based on old British road bikes!! This was up until the likes of Fantic who were one of the first to mass produce a purpose built machine. The tiller style top yoke is better for a "sit down" or more relaxed style of riding, the bars come back towards the rider so there's less of a reach to the handlebars. Stand up and this tiller leaves less room to ride behind, less weight on the front (when needed) and a less direct feel to the steering as the front pivot point (head stock) is further forward than your grip on the bars. What's changed? Us really. We know it's not always the best arrangement, other manufacturers have shown us the light, directer steering helps turning tighter and give a better feel of the front wheel, room behind the bars helps us move our weight around the bike better, makes an older bike feel a little more modern.

"..I dunno! Imagine a disc spinning on an axle that is far too small with no bearings so it slips about as it rotates" A squealing noise when running could be the crank bearings have dried out through lack of oil. This happens sometimes if the bike's been stored for a time as they do not sit in oil, but get the lube from the oil mixed in with the petrol, so no running, no oil. Though there are lots of causes to strange noises, as Grib writes, get someone who's familiar with 2 strokes to have a look. And yes, dull heavy running is usually a sign of a rich mixture.

I've just had a crack a freshening up a ty175 barrel. Stripped it off with Nitromors and wire wool. (Various poking sticks, a ruler helped get in all the nooks, even tied wire wool to the middle of a boot lace and pulled it back and forth) Cleaned it off and emery papered it down with lighter and lighter paper. Rinsed it off with white spirit. Masked off the bore etc. Painted it up with Halfords High Temp Enamel paint, it's a matt finish. (took two cans for both head and barrel) Then as with all good recipes, baked it a 250 C for an hour in the oven (the Mrs was out!!) Once it cooled, some more papering to reveal the edges left it like this

There's no engine oil inside a 2 stroke as such (you add that to the petrol) The oil I think your are referring to is the gearbox oil, an yes, this does include the oil for the wet clutch to run in. They'll be a drain plug underneath, yes it comes our better when warm. What oil are you going to use to refill? There are products like PJ1 clutch tuner that work well. A lot of people use Automatic transmission fluid, this works well as it's a very light oil, though the clutch can sound a light noisy running on it. As you have clutch drag, it might be worth removing the clutch cover, undoing the springs and removing the pressure plate and all the plates within. (notice how the plates alternate, fibre then metal and so on) Check there is some life in the fibre plates, ie that they are not all smoothed down. Clean the fibre plates like this, there's a download on the first post http://www.trialscen...eta-clutch-fix/ Also check the fingers of the outer clutch basket that run up the side of the basket. Seen here with the gaps between them. http://www.atvriders...utch-basket.jpg The inner edges of these fingers (where the tabs of the fibre plates run against) can wear notches or grooves in the alloy and the plates will not run smoothly against the fingers when on operation, a light file of these edges can restore a flat, smooth edge for these tabs on the outside of the fibre plates to run against, smoothing out the clutch action. Rear brakes can be tricky, as the pipe runs horizontally and the master cylinder stroke is small and short, air trapped in there like this is hard to get out. Try removing the caliper from the bike so the pipe runs vertically, this will help, you'll need to trap something in between the pads. Or with a big syringe and a short pipe, back bleed the brake via the bleed nipple on the caliper.

The fuels flowing out of the breather because something is making the float valve stick, so when the float, floats up, it isn't shutting the valve off. Dirt or old fuel can gum this up. Remove the float bowl off the bottom of the carb. Remove the pin the floats swing on, (should pull out from one side) right under the tab on the float assembly is valve. looks like this http://www.lambretta...mbd8649m35.html This valve is in two parts. First there is a stopper, I small, fat needle with a pointy rubber end, take this out and clean it with carb cleaner. Second is the seat that the fat needle fits into, this is screwed into the carb though there's no need to remove it, but clean it up with carb cleaner. Clean up the rest of the float bowl with cleaner while you are at it, it needs to be spotless. Take care the pilot jet isn't blocked as well, this is a little brass, button headed screw with a tiny hole in it (fitted upside down within the float bowl) Pilot jets look like this http://www.myscooter...--100/1486-100/ or this http://www.splatshop...mpaign=shopping Depending on which carb is fitted. Put it all back together, carefully. Try not to bend the tab that activates the float valve. (if this bends, it effects the level of fuel in the bowl, too low a float level= low fuel level in the bowl and the bike will run lean. Too high a float is the opposite,it runs too rich) Float bowl and tab look like this (tab is the metal forked hook seen between the two floats) http://www.dellorto....asp?PartID=6802 Make sure the bowl seal is still fitted and the surfaces are clean before refitting the bowl. Dump all the old fuel out of the tank, fit a little inline fuel filter (the right way around!), they are available on ebay for a quid or so and fill it with fresh fuel. Refit the carb and jobs a good un!

Yes, I think they still do. Yamaha Motor UK dated mine a couple of years ago. From the letter, it looks like Customer Services handle it, I'm unsure how much it costs. 01932 358000 I think you then need a MOT done on the frame number, insurance (again, they'll do it on the frame number for a week or so) then the DVLA form and fee, a load of proof of your ID and the cost of a tax disc. I think Yamaha will also send you a letter stating the import tax was paid, otherwise you get stung for that too! http://www.direct.go...icle/DG_4022316

I had the older Beta Zero that leaked the coolant through the seals on the water pump shaft. If my foggy memory serves me, there were two small seals on the shaft that needed replacing.

Ian Pebery (of Whitehawk) makes them. Like this in carbon on mine Also does a fibreglass one. Try searching the forum for his contact details

Hmm, why would you just want to change the big end bearing on it's own? The big end pin also wears as the bearing rubs against it, as does the faces inside either end of the conrod. Might be false economy to just replace the bearing. If you do just need the bearing, check the bearing cage for numbers (usually stamped/etched on one the end of the cage) With this bearing code number, you should be able to source one from a bearing supplier.