sadlotus

Doh!! Sorry.... 1973 M92 350cc

Hi all just/still continuing to assemble the motor and was about to bolt down the head, two bolts are in pretty poor condition. Can anyone tell me: (it'll be in the book no doubt, but I'm at work when i decided to write this) What size they are, and if they are anything special. I think I measured them at 8x50mm. Can I buy a couple of bolts from the local bolt seller or do I have to send off for them? ta verily Paul

Hi all, the rod, crank and bearing are all new. We have the Bultaco UK engine manual and the Haynes manual. When I saw the engine only one crank bearing retainer was in place and only nipped tight with two nuts/bolts. Tim, your assembly description was how he described it to me (except the wifey bit) and things only tightened up after the second casing was nipped up. He's having it apart this weekend and put on a lathe to check alignment - see what comes of that. Paul

Engine builder's just rung and said he's bolted the crankcases together and the crank is really tight. With a firm grip you can just about turn the engine over. It should turn smoothly and easily shouldn't it? He's thinking the crank could be out of alignment. He said everything seemed ok when the first bearing went in, then went pear shaped when the second went in and the two cases were tightened up. I have to add that I'm not very familiar with how the engine goes together but I think I trust him. The next step is to have it apart and have the alignment checked this weekend(ish). Any clues as to where something could have gone wrong? Ta verily 1973 Bultaco 92

Hi Lorenzo There seems to be several perputations of big end and little end thrust washers. That wider 30mm little end bearing in the picture is the correct one if there are big end thrust washers, but not if there aren't, because as you say, the rod becomes fully floating. I have two options; have the mains repressed with thrust washers or just replace the little end with a smaller 20mm bearing and new spacers. I need to have another word with my engine builder... Note to Mr pschauber... I have an ex Finnish engine builder who is an aeronautical engineer, ex Finnair and very particular, unlike his Polish tractor mechanic helper. I try to keep a nice balace between the club hammer and the sliderule. As to the distance between the mains bearing faces, I think this must be the length of the crank pin. By the way Lorenzo, mine is hollow with no pin, taper or otherwise, again, that's how it was when it came apart, as to whether it was like that when built...who knows. Just want to know what's best for longivety and robustness, I'm sure the two little end spacers will work just fine, but will the mains thrust washers give a more positive location? Think I've answered my own question there.

Hi all, thanks for the quick replies. I cant get hold of the person who pressed the crank at the moment, but he did give me back all the bits from before (unless he realised the two spare washers left over should have been fitted and threw them away - doh). The old little end did have spacers which would have centralised the conrod on the crank, so it may have been like this from new, (nearly 40 years? possibly?) but the new rod has a wider bearing with no spacers and will allow it to slide within the piston, and the crank. Anyway, the old rod had signs of rubbing along its length where it had been touching. Can someone tell me the width between the two bearing faces on the crank? I imagine these are critical and determine whether the crankcases go together without a gap. It will also determine the width of any thrust washers - although the parts book doesn't list various sizes, only 'thrust washer'. Am I missing something here? (apart from thrust washers... possibly) links to pics: https://skydrive.liv...M5mqj1YC-f_gDg" https://skydrive.liv...ACYU-Tdpw-Ac6e4 Ps how do you post proper easy to view pictures?

Hi, Just had a new main bearing and rod pressed onto/into the old crank. Question is: I didn't notice before but now the rod touches the webs... There doesn't appear to be any thrust washers. Is the rod held centrally by the piston? Are the thrust washers missing? Should there be any? It's a Sherpa 92 1973 thanks Paul

You're a star! Thanks! I thought my post was going to be alone forever........

Hi all, a strange request I know but I'm miles away from the bike for a few days. What are the dimensions of the Bultaco logo on the tank of a Sherpa - 92 if it makes any difference - which i don't think it does. The word 'Bultaco' specifically, and more specifically, the height of the letters. Thanks for your help Paul

Thanks for the replies, confirmed what I thought. I've been checking out the US ebay, but the shipping/postage seems to kill any bargain price. Naichuff, I have tried Lumiweld but on an ali radiator, I'm afraid I turned a previously acceptable bodyfiller bodge fix into an unusable blobby smudge of aluminium... thanks Paul

Hi all, my clutch cover is pretty bashed and where it's been repaired with filler and Araldite it's leaking (again). Surfing the web and trolling thru Ebay there seems to be three types of casing for the Sherpa. An early four speed version (almost smooth oval shape), late sixties/seventies five speed (round with bumps) and eighties and later (squarer, more pronounced shape). I have a Sherpa 92, 350 1972 middle version cover. Questions are: Various casings come up un Fleabay but rarely exactly what I need. Are the 125/250/325 casings the same? What other models/variations should I be looking out for? Ta verily Paul

Hi, you say: the paint on there being aero/space will stick most anything and any weather. tell us more, what is the paint? any names? Ta

Hi and thanks chaps, Nice to be able to pin down the model and know what are the good and bad bits. The more I surf the more I can see the differences between the early and late 92s (thank goodness for the internet!) Also the more I research, the more I see the bodges by POs. I'd love to restore the bike - if not back to original, at least to to a stage to make it feel proud again, but at the moment I'm having too much fun just chugging around the fields and tracks and through the woods. Think I'll start collecting the missing bits, front wheel and silencer is a good start, then see how it goes over the winter. Thanks for your help - a good start - I'm sure I'll be back for more. Tim - As for as the Lotus connection - I've had an '68 Elan S4 for a long time that was very sad when I bought it - nowadays it can hold its head up high and even on occasions give a wry smile to more modern machinery away from the lights - I suppose I should have called myself SadBultaco (there again, to be honest, I have seen sadder Sherpas) Paul

Hi all, First posting so be gentle. been a long time since I went on a trials bike, had all sorts in between. First ever bike was a Montesa 50 - went from Kent to Devon on that, then an Ossa Mar - went everyday to college on that, then a King Scorpion (not a trials bike I know) then a mixture; 650 Kawasaki, RD500, 750Turbo, BMW around the world and ZRX everyday (nearly). Always wanted to get back onto a trials bike and always admired the Sherpa. Here's what I've just (unwittingly?) bought, this is what I think I have, what do you think I have? Bought as a 1973 92 model Engine number: m-9201750 Frame number: b-9201729 But - all the below look different from online research... Only one top tab to hold rear mudguard on. No tabs to hold rear of slimline tank on - (tank's been cut down). But there are tabs further up where the seat frame joins. Front brake actuating arm on the back not front of the front hub - also has speedo drive hole and non rimmed wheel. (Frontera wheel/hub?) possibly looks like a TY F/brake. Does have chrome exhaust with rings for springs, but nothing to attach to on the head. Sammy Miller middle pipe and SWM rear silencer! No rear speedo - spacer instead. Rear shoes rotate around two pivots - not one as per manual - secured with wire not C clips! Cut down slimline tank - but bolts for attachment too high(?). Homemade brake pedal (possibly) No pinch bolts on top of forks. General bodges and odd nuts and bolts - I reckon this bike lived outside and had minimum care to maintain it. Questions: Is this a right bodge up of several bikes to make one? Or, like Lotus, did Bultaco do updates as they went long and according to what they had in stock? ie lots of overlap between models. What have I got? A proper ol'Heinz or what? I've ridden it around the fields and up and down a few gullies, pulls well, topend rattles when revved - but wont rev off the scale - seems top run out of steam as if it's oiling up (new petrol at 40:1). Forks bottom out when the wheel leaves the ground, slow tractor like response when snapping open the throttle not easy to lift the front. Questions: Is this a right bodge up of several bikes to make one? Or, like Lotus, did Bultaco do updates as they went long and according to what they had in stock? ie lots of overlap between models. What have I got? A proper ol'Heinz? http://s1197.photobucket.com/albums/aa422/sadlotus/ What does the panel think? thanks Paul