goudrons

Before you start stripping parts off and getting them tested! Check the following. Evos can suffer from a wiring fault with the connector for the kill switch. Not the kill switch it's self or the switches wiring, but the connector block attached to the bikes loom. Unplugging the switch won't make a difference, the fault is the connector on the loom. It shorts out and kills the spark. Get a multimeter, set it to read resistence and unplug the kill switch (should be behind the headlight) Probe the connector (loom end, NOT switch end) and see if there is a short circuit. I've just had this with mine and there are a few others on here that have suffered too, I just sliced the connector out and soldered up the wires. Another common issue is the low tension wire to the coil. It's a push fit, spade connector fitted to the bottom of the coil. It can get quite crusty as it's in the firing line of water and dirt, it can also rattle loose, the connector it's self can open up a little and it slips off the prong on the coil. Clean the connector and prong up first, then a gentle squeeze with some pliers on the connector will tighten it back up.

Yes, it's on the outside, just below the sprocket/output shaft. Large slot headed bolt with a plastic washer. looks like this http://www.ebay.co.uk/itm/GEAR-SHIFT-DETENT-BOLT-1973-OSSA-MAR-MICK-ANDREWS-REPLICA-250-TRIALS-72-73-74-/171581306804?hash=item27f30af7b4:g:GxMAAOSw0vBUixiv You can see it here, it's the only screw/bolt on this pic, so it can't be confused! http://www.ebay.co.uk/itm/1974-76-OSSA-MAR-250-CRANK-CASES-ENGINE-CASE-MOTOCROSS-TRAIL-TRIAL-ENDURO-/272054238399 As the shift drum rotates (when you change gear), the pin/spring flick into different dimples machined into the end of the shift drum and holds it in position. Without it they tend to slip out of gear as nothing is stopping the drum from moving and you loose that positive "snick" when you change gear.

Have you checked the detent assembly? The detent locates each gear in place with a pin under tension of a spring in dimbles which are machined in the end of the shift drum. It's behind a slot headed bolt with a plastic washer on the right side of the crankcase, just below the output shaft/gearbox sprocket. See pages 16 & 17 here. http://ossaengineering.com/wp-content/uploads/2014/02/OSSA-5-speed-manual.pdf

So it's sparking and as it ran before, you'd presume it's timed right enough to run, so don't mess with the timing, yet, not until you've ruled out fueling problems. As the plug is getting wet, it's fueling too, so it may be a case of it flooding up. Check this: A sticking float bowl inlet valve the open position will allow the fuel to run right through the carb and into the engine. They often stick a bit if the bike has been left a few weeks with fuel in the float bowl. You often find fuel pouring out of the float bowl over flow tube, but by the time you notice it's too late and the crank is flooded up. A sharp tap on the float bowl often frees the valve off, but it really wants cleaning and checking it operates as it should. As mentioned above, turn the fuel off and remove the plug. Lean the bike over as flat as you can get it on the left and work the kickstarter over and over. If the crank is flooded it will spit out black oily fuel out of the plug hole.

First thing to check is the spark? Remove the plug, rest it on one of the engine fins (with the plug cap attached) and crank it over while watching the plug. It can be hard to see in strong daylight, but you should be able to tell if it sparks or not. If it doesn't spark you need to check the rest of the ignition system, plug, plug cap, coil, points and condenser. If it sparks, dry and clean the plug and refit. Now repeated kicking over without it firing should, if fuel is getting through, soak the plug wet through with fuel. If when you check it after repeated attempts to start and it's still dry, you need to check the carb. Check fuel it actually running from the tank first, rust and muck can clog up the tap/filter inside the tank. Also fuel goes stale very quickly and can cause a green sort of gum in the float bowl that clogs the carbs jets, so it's worth checking the jets are clear by unscrewing them and holding them up to the light, also check the fuel inlet valve isn't sticking, this is the little valve that works on the float arm and regulates fuel into the float bowl.

I agree, it looks like a Miller Frame.

From what I remember (which isn't much), Rex Pile converted 22 Mick Whitlock Whitehawk frames to take a Mono shock. These are what's know as RamYams. R for Rex A for Autos. M for Mono. YAM for Yamaha. There does seem a lot of confusion about them and quite a lot of people still seem to think Rex made them in twinshock form too, though I don't think that's ever been confirmed. But you'd think they'd be badged as RATYAM! I seem to think the Ramyam and Whitehawk (for 175/200) didn't have rear frame loops, just two bars and the Hi Boy had a rear loop to the frame, but a pic of yours might help.

As Brucey writes, it can all get a bit pricey and complicated. Yes the swinging arm needs a bit of length and width as the original design was never made to fit such a large/wide rear wheel/tyre. But this is only half the puzzle. The wider tyre now gets in the way of the chain! You now need to think about moving the sprockets out further. The simple way at the rear is to fit a SM Products swinging arm conversion, it's wider, longer, comes with a chain tensioner, it also comes with a spacer to move the rear sprocket out from the hub. (doing this can give a brake plate issue later, but it can be sorted quite easily) There are other ways, but they are a real headache. One is to lace up the rear wheel so you get the right sprocket clearance, but you can't use a standard hub or you'll end up with one sides spokes at odd angles, the rear wheel will look like an open umbrella rolling down the road! You really need to widen the hub to get the spoke angles even both side. Once you have the rear sprocket moved over, you need to move the front over to match it. Again another headache as there's little you can do to the front sprocket except move the engine over on the frame. This requires you to move the front and rear engine mounts over slightly, but not too much or you'll not get the exhaust to fit the cylinder head as the down tube will get in the way. It's all possible with a bit of trial and error and fitting up and tacking before welding up solid. I did it and no one warned me before hand, it had me in tears, but I got there in the end!

You might want to check where it's leaking from first. Pump it up to around 30psi and spray around bead and around the spoke/nipples with soapy water. They can seem to hold air when you aren't riding, only for them to lose pressure when you ride. This is often caused by loose spokes allowing the rim to flex too much. You can often stop it by nipping up the lose nipples, but as it's a 2003, it might be due a wheel truing. It could also be down to corrosion around the inner rim, I've seen quite a few crusty alloy rims that have scabbed and flaked up around the inner section. If it's not too bad, a scrub with a fine wire brush will remove most of it. Once you are sure the spokes and nipples are tensioned and the inner section clean, fit a one piece inner rim band, one that has the valve bounded to the band. You have to lube the band and inner rim up well with soapy water, so the band snaps in place and evenly tensions it's self in one go and you haven't got to poke and prod it into place. If it doesn't snap into place first time and bunches up, it won't sit straight, so it leaks again!

I'm not a fan of all those instant gasket gunks unless required because there isn't a paper gasket. (like some Yams centre cases) If the mating surfaces are clean and in good condition, a greased paper gasket will be fine.

Lightly grease your gaskets. Apart from help keeping them in place when building up, it can stop them sticking and ripping if you have to remove/undo the parts again.

There isn't too much to worry about, just keep it all clean and adjusted. Though it is worth keeping an eye on the master cylinder seals. They can often weep or leak, but rebuild kits are available for a fairly painless outlay.

First check the pads. The minimum meat on them is 2mm, any less and the pistons in the calipers end up twisting in the bores as they come out too far and they jam on. Next check the free play at the levers. You need 2mm free play, measured at the end of the levers before the master cylinders are activated. If they are over adjusted you'll end up pumping fluid to the calipers but it not able to return and it jams the brakes on.

Find a Beta Rev3 manual, you'll find one on a beta importers website as a PDF file and check - reset the float height as stated in there. The carb slopes forward slope due to how it's fitted and it very fussy to float level, too low and it'll lean out quickly, too high and the flood up going down hill.

Is it the shaft and clutch inner moving or just the outer basket moving on the shaft? There's often a bit of float between the basket and shaft and it's normal as the outer basket spins freely on the shaft. The clutch inner (and shaft it's self) is usually tight or may have a tiny amount of play, but will feel a lot more solid than the outer basket.

Bladder control

The matte black paint on the frame, fork lowers and swinging arm on the 2014 can scuff, scratch and chip up, this can make it look a bit scruffy. The red 2013's always look mint! You'll probably want to go over it with the spanners, make sure everythings tight (like the rear sprocket bolts) Some of the threads in the alloy frame can strip, usually the ones that hold the seat/rear mudguard on or have been threadlocked. A cheap M10 thread insert kit will sort those. Buy some reticulated foam and stuff it around the top of the rear shock, this will stop a lot of water splashing up into the air box. As normal with Betas, those grills in the seat break free, you can mess around with hot glue and the likes and it might work for a while. I ended up screwing the things in place. Each grill held with 3 countersunk socket caps fitted flush. I used tiny M2's in black so they are hard to spot. No way they are coming off again! Clean and gently squeeze up the small, push on spade connector on the coil. It can rattle loose and it's in the firing line for muck and water. Make sure there's plenty of meat on the brake pads, they don't like it when they are thin. Re clutch, there's a guide to cleaning the friction plates up on this forum. There's also this http://www.betausa.com/sites/default/files/pdf/STT-2012-3-Evo%20300%20clutch%20set%20up.pdf The UK 300's came with a flywheel weight, it might have been removed by now. It's worth having, they work well with them fitted, but if it's still a bit of a handful, try a slow action Domino throttle (Black tube slow, White tube fast).

Yeap, a 2001, I had one too, though not many got sold that year in the UK due to the Foot & Mouth outbreak. If you measure the bore/piston: 125 pistons are 54mm 200 pistons are 64mm 250 pistons are 72.5mm 270 pistons are 76mm 2000 models were black/red with USD forks and air box cover on the left side. 2001 models were blue with conventional forks (as were all those since) and the air box cover on the left side. 2002 models were maroon and the air box cover in the seat (as were all those since). 2003 models were yellow. 2004 models were orange 2005 models were red/grey 2006 models were black/red/silver 2007 models were red with fat bars (4t black & red) 2008 models were red/white with fat bars(4t black & red)

Turn the airbox to carb rubber the other way around, this makes it easier to refit the carb.

From you pic, it appears there's not a Beta flywheel weight fitted as they come with a cover spacer that spaces out the flywheel cover. http://www.trialscentral.com/forums/topic/56767-beta-flywheel-weight-kit/ It's worth getting hold of a proper Beta weight kit (weight, cover spacer and longer bolts), they smooth out the power delivery a little and obviously weight up the engine for little more on the over run. UK bikes should come with them fitted up to 2015, from 2015 they came with a complete flywheel that's heavier, but that won't fit the older bikes. They sometimes come up on Ebay or try John Lampkins (UK Beta importer) for all your Beta specific spares, one from a Rev3 will fit as well. You might be able to save part of your mudguard, there is an aftermarket rear section repair kit you might be able to fit if you haven't broken too much of your original, again search ebay. A wouldn't worry about the map switch, it does very little on a 2 stroke, You can only make out a small difference on the Factory 300, I just removed mine as it was less than useless! If it's a little slow revving/picking up and feels like in needs a bit more wrist action, look at the throttle tube (that the grip fits over). Domino throttles come in two actions. A black tube is slow action. A white tube is faster. (they are only cheap, so is worth trying both, yes search ebay again!) Also check the sprockets, it should be 11T - 41T but some gear them down to 10T - 41T, that'll cause it to feel rather tied down. It's all about what works for you. I like the flywheel weight, a fast action throttle and normal 11-41 gearing, without the weight my 300 is a bit punchy as the main jet kicks in, but the weight really does smooth it out. There's two adjusters on the clutch/front brake, the outer one adjusts the reach, the inner one works on the master cylinder. If you screw the outer adjuster in, it moves the lever in towards the bars, but you'll need to adjust the other adjuster (master cylinder one) out a bit as you always need a little lever free play (2 mm at the end of the lever before it starts to depress the master cylinder). Without this free, when it all gets hot, the brakes/clutch will start to operate on their own. The same free play is needed on all the hydraulics, so the same with the rear brake lever. This http://www.betamotor.com/system/attachments/0000/5986/evo2t_2013_ENG.pdf and this http://www.beta-uk.com/images/pdf/2013/EVO2T_125-300_2013.pdf should be useful.

There are aftermarkets available. The three I know of are: Olle http://trialssuperstore.com/products/rear-shock-rev3-olle Wilber 630 or 640 series http://www.hermanusa.com/index.php?target=products&product_id=29844 Hagon https://www.hagon-shocks.co.uk/catalog/partdetail.aspx?partno=M68200

There often quite a bit of side play in the big end that can be mistaken as wear. It's hard to test, but you can often get the crank to TDC and grab the rod near as possible to the crank pin/big end, hold it straight and try lifting and pushing it up and down (without the crank turning) against the crank pin and feel for any movement, then try again at BDC. If you are going to replace it, you'll need a new con rod kit and gasket set (and while it's apart, buy and replace the main bearings and seals). I think you'll struggle to get the old rod apart and the new one needs truing up carefully, so hand it to a motorcycle engineer to swap the rod and big end out for you and true it up, it doesn't usually cost much if they have the right tools and know what they are doing. There a few tools needed to tear down the engine. A flywheel puller And something to hold the flywheel to undo the nut (and primary nut), you also need to hold the clutch centre too. A tool like this http://www.demon-tweeks.co.uk/Product.do?method=view&n=678&p=547524&d=124&c=4&l=2&utm_source=Google&utm_medium=Base&utm_campaign=Hand%20Tools&gclid=CIy2_qbAicsCFQMcwwodfNUNRQ One side (with the studs) will hold the flywheel, the other (with the bent ends) will hold the clutch centre. Using something else to jam these will usually end in tears! The rest are just usually tools.

I replaced the knackered rear shock on my old Rev3 with an Olle. The original Paoli leaked and it turned out the bladder had split. I couldn't track down anyone to rebuild it, lots of try here's and I think they used to, but never actually found anyone prepared to tackle it. From what I remember the Olle was alright, nothing special, but it was fairly cheap when compared to other options. It took a few attempts to get it set up right, at first it seemed a bit too lively for me, but it wasn't a faff dialing it in. I think at the time Olle were fitted to Jotagas.

Setting up a carb can be a bit frustrating and can take a bit of time and effort. It's driven me it up wall many a times, getting the bike running well in the garage only to drive out miles to an event and it run like a bag of spanners and the very last thing you want to be doing is opening up a carb in a muddy field! Then once you do get it somewhere that seems right, you're always wondering it it's good enough, could it be better, To add to the headache it's not uncommon for a different settings to work just as good as another, but you have to start somewhere! Eurocarb has sold 4 slightly different VHST kits for the Rev3 over the last few years, all with slightly different part numbers, jets and atomizers and they all seem to work, then again, anything is an improvement over the Mikunis fitted at the factory! I've set a couple of VHST's up on different 250cc bikes and to be honest, they all end up very near one another as I used the first as a starting point. D37 needle 50 or 55 Slide 200 to 250 inlet valve 60 or 70 choke 3.6gm floats There are a couple of different atomizers that work, 271HE and 272HH Pilot between 36 and 40 Mains tend to be somewhere between 100 and 110. If you have these and are riding in Kent, I might be able to help you set it up as I ride in the NKTC. Worth noting Dellorto's are prone to pilot clogging if the the slightest spec of grit or dirt gets in there, so make sure you've a clean fuel filter installed and keep the airbox and filter clean. Also drain the float bowl after every use, modern fuel goes stale very quickly and the green gunk it leaves behind will also clog it up pretty quickly.

This might help with jetting http://www.dellorto.co.uk/shop/dellorto-motorcycle-carburettors-parts/complete-carburettors-dellorto-motorcycle-carburettors-parts/vhst-24-to-28mm/r9351-vhst-26bs/ Though I've found Eurocarbs pilot jetting always seem a bit lean for slow trials work, so it might be worth buying a 37S and perhaps a 38S as well. (38S works better in Rev3's) Also, 60 choke is a bit mean, in the past I've ran a 0.7mm drill through them to aid cold starting. As for fine tuning it. Start with centre needle clip and mixture 1 to 1+1/2 turns out as a base and screw in the fast running a bit to get it started and idling fast to warm up. Dial in the idle speed and mixture until you get it to idle smoothly at the desired speed. WOT should be right on that main jet. Adjust needle clip down or up to dial in throttle transition from idle to main (around 1/4 or 1/3 throttle opening). If it bogs or coughs opening the throttle and needle is fully lifted, move up an pilot size.