JonnyWobbles

Hi Rabie, yes the detailed workshop manual. I’ve just found it - not sure why I couldn’t before! Finger trouble 😮!

Hi Rabie, yes the detailed workshop manual. It looks like it used to be on the Beta website but they probably removed it.

Thanks, yes I’ve found the service and user manuals but not the in-depth workshop manual that provides the real details on engine strip-down etc.

I’ve been trying in vain to find a workshop manual for my 2004 Rev 3 250. Previous posts seem to confirm that one doesn’t exist for the Rev 3 but the later (2009) Evo engine can be used as it is very similar. The problem is all the links to this manual (mainly the USA Beta site) are broken. Can anybody please point me in the right direction on the web or where I could get a copy of the engine manual at least? Thanks!

I’ve been recommissioning a 2004 Rev 3 and although it appears runs ok (on the flat, yet to try on the hills) my Rev 3 appears to have a bit of a piston knock at all revs. I’ve taken off the head and although a bit coked up the piston and cylinder bore looks in good condition. Whilst there is no detectable play vertically, I’d estimate 1mm play fore and aft and side to side for the piston in the bore. The piston is stamped 72.457 (04-14 8724) and I wouldn’t be surprised if this is the original piston but can’t find the exact measurements for the pistons or oversize replacements if anyone has these please? Is the lateral play acceptable or does this point to cylinder/ring wear and or the small end bearing etc? What would be the best course of action to refresh the engine, new rings, an oversize piston kit or cylinder re-plate and new matched piston etc? I’m new to 2 stokes so any advice greatly appreciated! cheers jon

Hi, I’m just recommissioning a 2004 Rev 3 that’s been laid up for a number of years and could do with some clarification with respect to how to correctly set the chain tension. The manual shows 20mm gap from the top of the chain tensioner to swing arm. Not easy as my tensioner is a bit skew-if, and is this with the bike supported on a centre stand, on the ground or loaded etc.? Searching for an answer throws up various methods and suggests tension should be set with the axel / swing arm pivot / front sprocket aligned i.e. effective maximum length. Any help as always gratefully received! Cheers

Gents, good to hear from you! You're right I did move the Sherpa on to a new home really due to the left hand kickstart which due to my dodgy knee I was struggling with. But I agree with Lorenzo that with the right tools (DTI with good solid mount, DVM with buzzer etc.) and practice which gives you an appreciation of the small variances when tightening things down etc. its not really a problem (and arguably part of the attraction of older technology bikes!). My issues were with poor quality aftermarket points described above once I sorted those out I set it up and it started no problems at all. I must admit I did fit an electronic ignition to my Triumph Bonneville T140V (Tri-Spark) which was originally a bugger to kick and sometimes tried to break your ankle for fun! It is very good as it automatically retards the ignition at less than 200 rpm to ease kicking and does remain set. I just need something to automatically balance the carbs as like the Bultaco is a matter of developing a technique - in this case two drill bits inserted under the carb slides that nod when twisting the throttle! I am after another trials bike if you know anyone selling a righthand kicker! Cheers Jon

A couple of people have asked about the fold out lever I have fitted to my Sherpa 198A that was for sale (now sold!) and I promised to post some photos and quick description of how I made it. Its not an original or expensive remanufactured one, but a right hand pivot lever with 13mm diameter splines (the Bultaco shaft size) that I found on eBay for £13 - allegedly Honda derivative but I can't confirm as it seems a pretty cheap copy. Basically I removed the lever from the splined boss (circlip) and simply filed away the metal to form a curved profile matching the opposite side allowing the lever to pivot both ways. Not being manufactured quite symmetrical the lever pivoted past the 90 deg. point to the left. So I drilled a small hole and bonded a screw and filed off the top so that it acts as an end stop (shown in the 3rd photo below). The splines are not a perfect fit (seemed to be cast rather than machined) and the lever needed a tap with a soft mallet to fit; however, as quality of the lever metal is pretty poor and soft compared to the hardened Bultaco shaft the lever splines will wear before the shaft and its a good tight fit when the pinch bolt is fastened. The result works very well and provides loads of clearance to the left mounted brake lever, frame (already chipped!) and foot peg which makes the kicking far easier than with the standard lever. I know of one forum member who has already tried this on an alloy lever made for a pit/trials bike he bought cheaply on eBay again with good results. I guess most 13mm splined levers should work and wondered if the better quality lever made for the Bultaco Astro had the correct spline size? Trust this is of interest and for less than £20 and an hours fiddling definitely worth a go! Cheers Johnny

Thanks Tillerman6, all good advice! I use a DTI to find TDC and good multimeter to check points opening. Bultaco quote piston mm back from this to set the timing so its fairly simple but time consuming as I found you have to repeat the process a number of times as the measurement is affected by points gap, flywheel torque setting, magneto backplate screw tightness etc. But once set up it works and I've not suffered any kickback or reverse running since..... Can also vouch for ACF50 - I've been using it on my cars and bikes for many years! Cheers

Now All Sorted! 😀 Thanks to all who helped with advice etc. InMotion replaced the rogue set of points they had sent me. Spent an afternoon resetting the timing and checking everything (multiple times). All back together and started 3rd kick In the right direction) and then easily thereafter! So its probably time to move her on and let someone use her as I've another project (I'm cafe racer'ing my Triumph T140V) that I really need to move into the garage and I don't think I'm going to get chance this year to do any trialling! I added up what I'd spent on the refurb which was rather frightening (don't tell my wife!) and listed it on eBay and our classifieds. Hopefully I'll breakeven! Cheers Jon

So the saga continues! Armed with a new set of points from InMotion, I set about sorting the timing to the Bultaco procedure other than using a multimeter (on beeb) connected to disconnected black wire and earth, dial gauge through plug hole to set TDC etc. First problem was setting points gap to 16 thou. as the hole in which the screw cam adjuster works on the points is too big and significantly bigger than original points. Eventually managed it by levering with screwdriver. Second problem, impossible to set timing to less than 5mm BTDC as there was insufficient adjustment on backplate slots! Comparing points seems to explain why! The angle and length of the insulated cam follower on the InMotion points is totally different compared to the ‘original’ points (fitted to bike when I got it) and a set of points I bought from F’ecked which themselves are faulty as the welded contacts are intermittent! I think a couple of mm and approximately 30 deg angular offset is not really acceptable if these are the supposed to be compatible! So for now I’ve put original points back in (contacts are good, but cam follower looks worn) and set them up to 2.5mm BTDC with none of the problems above. But I’m really not impressed! No wonder it’s difficult to get these bikes running correctly if the quality and specification of the current points available is so poor! I ran out of time (and patience!) so not put it all back together. I don’t think that the wear of the cam follower should affect the timing once set correctly, but I’d really like to replace with a ‘proper’ quality set if anyone knows where I can get some! Anyone want to buy a Sherpa?

My points were obviously a copy and I’ve emailed the supplier today (Feked) Where do you get the Femsa points from? I relocated the new condenser as recommended when I rewired the bike. Multimeter is a good bit of kit, I used to be a proper hands on electronics engineer in my youth before becoming a desk bound email answering ‘engineer’ 😀! But thanks everyone, you’ve confirmed what I suspected that it must be the timing. So I’ll get some proper points and start again checking everything as I go! I report back! Cheers

Points opening checked with a multimeter, connected to (disconnected) black feed wire to coil. Also disconnected green from earth to prevent path to earth via magneto coil. Obviously this will detect when points first open, not when fully open. Is this correct. Not sure what difference in mm this would make without measuring, but setting when fully open would effectively retard ignition. Which is what I think is required! lorenzo with regard to the modern points, I’ve none to compare but can say that a brand new set I purchased were faulty and intermittently went short circuit. Very poor quality when you look at the riveting etc.

Hi Lorenzo, no checking timing point done before reassembling and then trying to start. Have to say given the method of using the DTI to set distance before TDC infers accuracy, but given the problem and feedback it seems rather suspect!

Cheers, can certainly say the woodruff key is ok, as I had the flywheel on and half a dozen times checking the timing. Thing is it was only a couple of weeks from running ok to current problem?