peterh

I have just gone from a 2009/2010 Evo 125 to a 2012 Evo 200. I had fitted Boyesen Reeds to the 125 and re-jetted it and had a fast-action throttle and it was a great bike. It would go wherever I (at 72kg) wanted it to go and would go places in the correct hands that I would not want to go. It needed the revs but was very willing and felt very nimble and light handling and yet was essentially the same weight as the 200, 250, 290 Evo. It taught me better skills. Now with the 200, there is more power but it is "softer" power, appears to have more tractable low down power and doesn't need the revs to go the same rock steps, logs and climbs and more that I was doing on the 125. It seems smoother (it has a slow action throttle on it, so that may help that feeling), but I haven't yet felt the need for a fast action. A happy Evo 200 rider.

Careful - caustic soda is not good on aluminium. It will eat away at the aluminium. Do not use caustic soda based degreasers. Use a solvent based degreaser or leave it to soak for a while in petrol (the longer the better).

The website mentions its use for 4-strokes - any thoughts on this process for 2-strokes??

You may need to make adjustments to jets and needle height. I fitted Boyesen Reeds and followed this process as doing plug chops was not all that 'neighbour friendly' in our short cul-de-sac. http://www.smellofdeath.com/lloydy/jetting.htm Rather than adjust needle diameter (buy buying a new needle) I lowered the stock needle when I needed to make the bike leaner from 1/2 to 3/4 throttle. Worked a gem and so easy and telling and result was excellent. Am about to get new bike and will fit Boyesen again - have also used the X-Wing in a Keihin 28PWK and very happy with the result. All the best.

Workshop Manual from American Beta is here http://www.americanbeta.com/sites/default/files/pdf/2012Support/Service%20Manuals/Mototrial/2009-2012%20Evo%202%20stroke%20Engine.pdf Page 45 has the details.

Have a look at www.fantic.nl http://members.quicknet.nl/sw.zeinstra/htm/trial/thumbs_trial_6.htm You can see the various models. By memory, the motor cc and engine number are on the back right hand side more or less right under the exhaust expansion chamber - may be hard to see.

I have fitted them to my Evo and agree, they feel bigger underfoot than they are, they seem to feel as if it gives a very good platform to stand on. If you do get a set - check that the grub screws are well screwed in or use some loctite (or similar). I lost one on the first ride out and now need to try to find a replacement. Well worth it compared with originals.

Have you considered a set of Boyesen Power Reeds - dual stage reeds. will improve bottom end, normally need to lean the main and close down the air screw (and maybe sometimes increase the pilot/slow jet). But not sure about the altitude influence.

Thanks - looks like my measurements were about correct, so maybe the deterioration of my one surviving one is not too bad. 2-7/16 x 3/32 is 61.6mm and 2.62mm Found a useful sizing chart here: O-ring Sizing Chart - see row -143 on this chart. According to the specs for the Nitrile o-ring - can take up to 250

Hopefully you do consider a Beta 125 as well. I have a 2009 Beta Evo 125 and very happy with it (got back into trials after 19 years away). There were some problems apparently with the 2009 frames and swingarms (do a search on the Beta forum on this site for frames). I bought mine 2nd hand and it had had the updated frame/swingarm (2010 model?) on it. Have put in a set of Boyesen Reeds and decreased the size of the main jet from 125 to 118 and found that has improved the bottom end incredibly. Much more low down torque. I have heard some riders who have the 2008 model that they much prefer the simpler shock linkage for cleaning and maintenance. Great bike, great geometry, turns very easily and I have seen much more skilled riders than me, riding alongside and beating riders with 250, 290's and 300s in non-junior trials. And then seen juniors clean things on their 125s that I only take pictures of!! Good luck and watch out - you may want to ride the 125 rather than the 315!! (whoops thats the bully).

Can anyone tell me the size of the 2 x o-rings between the main pipe and the mid-section of a 2009 Beta Evo. The dimensions for the internal diameter and the thickness of the o-ring would be ideal. I think they will be something like 62mm internal diameter and 2.5mm thickness, but mine are rather deteriorated. The parts book and the workshop manual do not give the size. Thanks for assistance.

Cota 200 Specs Wheelbase 1305mm Ground Clearance 322mm Length 1990mm Seat height 770mm Overall height 1085mm Width of handlebar (std) 1085mm Weight 83kg PM me if you want pdfs of parts or a french datasheet for comparison of Cota 200, Fantic 200, Bultaco 250, Montesa 248, Ossaa 250 Cheers

Try the Beta UK Technical Information. This has PDFs for the various years. Using the 2003 pdf my interpretation of the numbering system is a 270cc.

Sending you a link to this site that has fuel:oil ratios as an image down the page - you may find this helpful. www.trialtech.com.au - there are lots of these around. Beta Manuals for specs - you can get the user manual here that will give you all the details. 550cc is the required amount for EVO 2T (see page 45 of the manual) - I use BelRay GearSaver 75W. Works well.

Check the specs in the manual at: http://www.betamotor.com/en/support/manuals

According to the User Manual (see http://www.betamotor.com/en/support/manuals) air screw should be 1.5 turns out from fully closed (closed is fully clockwise - so 1.5 turns from that position).