Tr1AL

@wayno57 according to that it is a 163cc motor which should be a 1994 JT 160 , or called a 200 by some people , look on the cylinder it may be marked on there although it could have been converted to a 125cc at some stage in its life as those two capacities share the same crank/conrod assembly. If you want to be sure then drain the coolant and take the head off and measure the piston diameter , if its a 163cc it will be 64mm dia , if it is a 54mm it is a 125cc , the gearbox/clutch casings look the same on all the variants so it could have had a complete motor change at some point and be a 250 or larger , as i said you will know by the piston diameter.

Make drawings and take photographs /video when you strip the gearbox to remove it and place it in its order using rubber bands to keep everything held together in their specific order on the different shafts to help you when you put it back btogether again.

@Chrissy1990 This may help https://trialsport.com.au/beta/Manuals/mikuni/

Buy a carb re build kit and new floats with a new needle jet along with a new fuel shut off valve as well then take the carb apart completely and clean it thoroughly , preferably with a ultra sonic cleaning bath and blow all the air passages out with compressed air , set the float height up as per the owners manual and put the recommended jets in for your country. Turn the fuel tap OFF every time you park the bike up to walk the sections and any time the motor is not running to help avoid the flooding problem ,

YAMAHA or SHERCO motor , if its a SHERCO then Splat Shop have 24X58 for £25. If it is a TYZ motor did you call the UK SCORPA importer Birkett Motosport.

@lemurGasGas 80 and Beta 80 versions have senior models that run with full size wheels i.e. 4;00x18" and 2.75 x 21 , they have shortened frames and swing arms with lighter tubing but are close to full size bikes.

@eirik You are very lucky to have a great bike and to be buying your 125 next year , I wish you good luck and hope you enjoy yourself on your bike as much as I enjoy riding mine.

https://youtu.be/V09zf7kfKKA?feature=shared

Here is another www.bjracing.com look under Vintage Trials Yamaha

Here is a starter for you https://www.yamahaty.com/english/tyusineen/majestyen.html

Here is interesting information for comparison Dexron Vl or Dexron 6 is 6.4 @ 100C , While this next one is the big surprise Motorex Trial 75W Gear oil specially developed for the new KTM GasGas GP box / wet clutch has a viscosity of 14.2 @ 100C . I have put the Motorex Trial specific oil in a pre KTM GasGas Pro and the Clutch was a little draggy under normal use with it adjusted correctly with the usual on/ off action. So if you are looking for less drag then Putoline GP 10 would be the best bet in theory.

Hello John good luck with your return , I think your choice of bike is a good one , It was my second trials bike ownership when I was 17 years old and they have a surprising amount of power for such small displacement having said that the Fantic 200 was of course only a 156cc but was a good bike in its time also. It is good to have excitement in life at any age so here is to that . This may be of interest to you http://www.bsaotter.com/nick_draper_the_return_and_ty_yamaha_s.html

Localised heat to inner bearing race of main bearing , oxy acetalene welding torch or use of a case splitter tool home made or ready made ?

As you are used to the Yamaha TYZ motor in the Scorpa I think you may find that the Beta 200 feels equal too it in terms of power output as motors have been developed for more power and better response than back then because of the obsession now with going up great big steps , at 13 stone I think you will find it plenty powerful for your needs /likes . Enjoy whatever you choose.

How much you weigh is a factor if you are choosing an engine size on a trials bike if you weigh 17 stone go for a 250/300 , If you are 12 stone or less 125/200 is plenty of power for riding the easy white route. There have been younger riders that have completed the Scottish 6 Days on 125cc bikes in recent times , 200cc has much more power and torque to do what you need it to do , If you are wanting to do road trials/National events sometime in the near future you might want to consider a 250cc.

Alfonso will need to show you the white easy route in the UK , Riding in between the sections to get to them on that route is usually the challenging part.

You really are in Trials central, best place to be if you want to ride rock as well. Good luck.

In case you do not know it has an allen key fitment inside to tighten it.

If you will be riding a lot of muddy venues and you are interested in messing about with your bike then these things matter but the newer version will be fine , you just have to adapt to the way the bike is set up in any case so it will not be an issue , in mud use a black domino throttle tube and in the dry use a white throttle tube , they only cost about £17. If you ride mud Use an IRC Rear tyre in place of a Michelin or Dunlop.

It does not need any sealant or PTFE just the new washer put some copper slip on the threads before re assembly for future easy removal Do not go mad tightening it it does not need to be super tight to seal , just nip it up.

They changed the way the stator and Fly wheel is positioned in its housing for reasons of gyro effect and this means that adding fly wheel weights has changed. People dont like change on the whole but there are'nt really any other major changes to the bike , Buy an older version if it is bothering you.

My advice is buy it , Beta Trials bikes are made for the club rider and If you are riding easy white route you will be completely over biked so you will have plenty in reserve as far as power and the bikes technical ability and they are a cheaper option with fairly good spare parts availability they have a steep steering head aswell so turning tight is easier.

You are absolutely right of course but it is probably just less than a teaspoon of oil burbling about in a very thin bit of tubing on an old trials bike that can be used for years in that condition if only ridden once a month like a lot of people do owing to work/family commitments. Its not really worth rebuilding the motor just to try and stop that happening when the motor will happily run for 4 hrs at a time for a practice or competition session without problem.

i have experienced the same with the correct oil amount and everything as it should be and i just fitted a long piece of tubing that ran up to area above the fan shroud and the oil did not syphon up and out the tube it just moved up sometimes and then drained back into the case when the pressure in the case reduced. Here is something interesting not a GasGas obviously but shows it is a thing . https://youtu.be/V_RoMVsMDkg?feature=shared

TYRELL CORPORATION 'More human than human' we are no computers Sebastian.