lorenzo

Mag. outer cover cannot loosen the flywheel nut - the cover is marked as a result of the nut having loosened when the key sheared. (Crank rotation suggests that the nut would actually be tightened, not loosened). The reason the key sheared is the the poor condition of the shaft taper - it's this and its fit within the flywheel boss that determines the security of the flywheel - the key is there in the main to locate the flywheel/points cam in the correct place. You need to address the issue of the damaged taper(s).

It needs a k/start return spring https://www.inmotiontrials.com/product/bultaco-kick-start-spring

Hi, Glenn - As suggested by bult360, I think it's most likely that the tank with the bulge is a one-off user mod. Homelite tanks were fitted to UK market bikes when fi-glass tanks were made illegal for road use - I think starting in late '73. This covered the range 124/125/150/151, which all shared the same frame. Presumably, the same regulations also applied to the Alpina - my '73 mod. 85 came to me in 1988 with a Homelite tank, albeit with non-standard paint (covering non-standard dents and filler/"bondo" !) It has straight sides left and right. Homelite tanks were also offered by Sammy Miller (and possibly others) as an after-market update along with his version of the Slimline fi-glass unit. Page from Miller's '73 caralogue :- Hope this helps.

Well, of course he would....... we are not rating riding ability here....... I thought it would amuse to compare a rider apparently using a tree with a rider actually using one. I guess you don't share my sense of humour.

James - Looks like you're on the right track. The condenser needs to be earthed, i.e. the outer casing needs to make electrical contact with the frame. Don't buy anything in the way of more parts just yet. The two screws fixing contacts to stator plate enable the gap to be set at .016" (or .4mm) fully open : slacken big screw, turn little screw either way (eccentric cam), tighten big screw. The cam that opens the contacts is formed around the centre boss of the flywheel - make sure that it's smooth and rustfree. The "lift" part of the cam is around the keyway and you should refit the flywheel with this at the bottom to avoid damaging the points operating heel., making sure that you don't dislodge the key (For the time being simply re-fit stator plate with screws in centre of slots). Once the flywheel is back on you should be able to adjust the gap as necessary through the two little access windows. Here is a schematic of the ignition system, which you may find helpful :- With the spark plug screwed in there will be considerably more resistance when kicking - for this reason DO NOT kick when magneto cover is removed, as this could bend the shaft......! Don't leave fuel in the tank - the ethanol content will dissolve the resin, and you will add a leaking tank to a list of other things to be fixed.......

James - Already looks way better after a clean ! My intitial suggestions were based around the assumption that the bike was actually running before it was stood up, and doing the absolute minimum to get the igntion working and seeing if the engine can be persuaded to run. Wiring to kill switch looks like a piece of old rubber-covered mains cable.......bin it. Does the engine have compression ? (A drop of oil down the plughole may assist what's already there) Is the fuel tank alloy or fi-glass ?

James - Welcome to the forum - nice to hear from a Bultaco owner from my neck of the woods. Bike looks like it's been standing around for a while. Re the lack of spark : Where does the HT lead tail off to ? (Can see it attached to the coil and the plug, but it seems to disappear off the pic.) I think for starters (sorry for the pun) you should ditch, or at least disconnect the kill button, which looks so rusty it may be causing the problem. Then check out/remake the connections and clean the contact-breaker points.

gooey - Yes, you're quite correct - hadn't seen that one ! I tend to look no further than the UK site, otherwise it can get VERY expensive........

If you mean item # 264418176169 on eBay UK, that's right side fitting, and steel........ What the OP wants is an alloy LEFT side lever :- like this one removed from my model 159, and shown here with an alloy right side lever of the type which would have been fitted to his 199A originally. I think most of these alloy levers were replaced from choice with aftermarket steel fabricated levers - seems metisse is going the other way !

Feetupfun - I was about to post "Like this one"........but you beat me to it ..........

Lee - Any developments / "Eureka!" moments in your search ? Reading through your o.p. again, I feel that what you are seeking is probably a model 85, or possibly a 98/99 derivative. This would be the closest of all in general characteristics to the Sherpa that you once owned and enjoyed (and regretted selling). As you have already discovered for yourself, a model 85 is in essence a mod. 80 Sherpa with altered gearing/larger fuel tank/lighting/more comfortable seat (allegedly).....which would suit well your requirement for "end use of unhurried trail riding". Add to this that the model 85 appears to be the most numerous Alpina for sale (Spanish or U.S. imports, usually) and as a result the easiest for which to obtain parts. You can also dismiss all the hassle of replacing flaking chrome brake drum surfaces - mod. 85 doesn't have them. The original "parallel" front hub and 2-piece rear (i.e. the one with bolt-on spoke flange r/h.) have 'cast-in' iron liners. A no-brainer ? Good luck with your search, whatever you decide upon......

Hi, Old man - Kart - model 5 (not 55) originally available in 100/ 125/ 175/ 200cc capacities, I believe.........??

Further supported by the use of top yoke with taper-top stanchions - (on a 198 the top yoke would have 4-bolt split clamp with parallel-top stanchions.) If the frame is stamped RM198, it probably was - that's an engine number............. Tank/seat unit is standard Bultaco Slimline/Kit Campeon, which also matches model 91/92 from 1973. Whatever, frame is an obvious re-stamp.

In terms of function on the machine, little or nothing............ However, you may have forgotten saying in you earlier post :- suggesting that no one would be prepared to pay such a price (for a brand new, super duper kickstart lever, even). The "used prop stand" reference possibly proves otherwise, I felt..............

Model 80 - £160 + p&p is exactly the price that someone paid earlier this week to win an eBay UK auction for a used prop. stand for a Model 199.......... After seeing that, I'd say anything's possible !

Hi - You have my sympathy - I know from my own experience how difficult it can be to obtain this sort of information, and I'm surprised that you've had no response so far. Not at all sure if I can help , but here goes :- Standard M91 Sherpa rear wheel is the same wheel as M92 and also (late) M85, and features 17mm. dia. spindle, WM2 (1.85 X 18") Yellow label Akront flanged alloy rim, and butted stainless steel spokes with alloy nipples. The outer spokes on the brake drum/sprocket side have an extra bend in the butted portion at the outer edge of the spoke flange - without this bend I imagine it would make achieving the required offset quite difficult. lf the chain comes off the rear wheel sprocket these 9 spokes are frequently those that get damaged. Does your wheel have standard spokes and rim ? Is the rim itself badly buckled, and if it is, what will you use to replace it ? Is the rim correctly laced to the hub (X2's pattern) ? Here is a sketch I made of a M92 rear wheel, mebbe 40 or more years ago - ..........I can't of course claim that these are the standard offset figures (or that I was able to measure them with any accuracy, come to that..). However, as the bike and its wheel had only about 2 years use at the time - there's hope ! Let me know if this is of any help at all, or if you need any more info. A check on the M85 wheel gave a figure of 1.5" for the sprocket mount surface to rim outer edge, rather than the 1.21/32", but I rather fancy this is not right - I have a suspicion it's been laced incorrectly.

Bill - (I am assuming that this tank is fi-glass) By my (somewhat shaky) memory, I think the Miller tanks used a "Ceandess" bayonet fit cap, of this type :- www.feked.com/2-vented-petrol-or-oil-tank-filler-cap-chrome-plated.html Not sure of the size, you must measure. Feked.com took over the Sammy Miller Products brand a while ago. Hope this helps - good luck with the rebuild .....

Johnsy - I was about to ask why you think synthetic oils are unsuitable for 50 year old engines, but b40rt beat me to it ! In the past, my own experience with 2-stroke engines that have been stored in average conditions and unused for a long time is that without exception, after being put back into use they consume their main bearings (and/or con. rod bearings) shortly after, even though those engines may have sounded surprisingly quiet and OK initially. This seemed to happen irrespective of the make of bike or brand of (mineral) oil used. My last 2-stroke bike acquisition in May 2016 was a 1996 moped that had stood in a garage unused since 1999. With 17.5K miles on the clock, a 20 year old bike that had its first MOT when I put it back on the road !!.......This little bike that I still own and use for the occasional local errand is up to now the ONLY one I've owned that has broken the bearing failure pattern - and I'm quite convinced that the reason for this is that it has been lubed with Fully Synthetic oil from new. Malcolm - I will tell you that Castrol R is definitely unsuitable, even if you find the smell irresistible - don't let the stuff anywhere near your rebuilt engine PLEASE..........

Larry - I feel fairly sure that the original twistgrip would have been Spanish Amal - not # 364 (a roadbike type) , nor type 16 - at least , not the type 16 listed by Burlen.............. (quote) "which has a high quality polished aluminium finish rather than the original chromed Mazak" also hints at the latter material being the earlier. Polished alumimium ? And with a price tag of £71.82 ? Whaa ?? Sounds much more like a fancy road bike repop than a trials bike offering to me. Anyway, while going through the shed in the summer (seems a lifetime ago now), looking for a Doherty twistgrip which I didn't find, I managed to turn up something like ten others of various makes and types, including :- Two Spanish Amal (Mazak) t/grips, a plastic one (like yours ?) all removed from Bultacos , and a Doherty with stripped threads -the one that I was hoping to replace. A feature of Spanish Amal twistgrips is that the cable entry to the drum is slotted and direct (definitely NO loose ferrule to drop out and lose. My Sherpa 4-speed parts list (a Sammy Miller copy) lists handlebars (part #10.01-019) but no twistgrip, unfortunately.

If the brake drum is 125mm. diameter, it's a Pursang wheel. (Pursang pre-mk. 9 - this used 140mm. hub/brake). Further identification points are the extra flange on the l/h. side of the hub, and yellow Akront label. This is supposedly a stronger wheel overall than a Sherpa item. First Sherpas with conical hub were machined and polished. Later Sherpas were less "finished", retaining the extra flange and were fully painted. Spokes also changed from stainless butted with alloy nipples to steel during various iterations. As stated by woody, flanged type rim was used to 1972, flangeless thereafter. Mod. 80 Sherpa and Mod. 85 Alpina both had full-width type hub of 125mm. and flanged rim. It'll certainly need brake shoes.......what state is the brake drum in ? .

Looks like Bultaco, but model ?, can't be sure.... Need to see other side of hub.

In a d.c. (battery and coil) ignition system indeed it would......... Unfortunately, a flywheel mag. ignition doesn't work like that - for the reasons already stated. The buzz box is NOT just the same as using a multimeter, as the bleep or buzz will continue to sound, but change note - the whole reason for using it is that when the contacts start to open there is still a complete circuit. - look at the circuit schematic again, in particular the ignition coil. You will see that there are two coils (l.t. and h.t.) either side of the core. That's quite correct..............But that's not what a buzzbox does. We are not testing resistance or points condition, but indicating a change in resistance in the circuit when the points open. That's your reasoning, but once again you are describing the operation of a d.c. (battery and coil) ignition. I'd love to be clever enough to claim it as my reasoning - I'm not.........and it isn't. If you don't believe an a.c.mag. flywheel ignition system could possibly work you have failed to grasp the basic principles. I admit I struggled with it myself before getting my own buzz box I'm rapidly running out of ideas to convince you........

Mike - Any progress ? Did you visit the "buzzbox" site ? I just turned up this:- , which may well explain better what I was trying to convey in my last post. You are of course free to ignore any of the above and/or form your own opinion and act accordingly - it's your bike,etc........

Mike - The reason you are having to remove the c/b. points wires to show when the points open is because you are using a continuity meter/ohm meter. In a flywheel magneto such as you have the condenser and h.t. coil are connected in parallel to the l.t. coil windings, which means that regardless of whether the contacts are open or closed, you will still have continuity. (Effectively, the contacts are always grounded........) This advice would apply to coil and battery (D.C.) ignition NOT flywheel magneto (A.C.) ignition in discussion here. Clearly, no it doesn't...... To time your magneto the accepted method is to use a timing "Buzz Box" which will indicate when the points open using a change in resistance, rather than an actual break in continuity. Additionally, if you are using a d.t.i. or timing stick/plunger in the spark plug hole, it's an awful lot easier to hear the opening point than trying to watch the flywheel/contact points/piston position indication, etc. all at the same time ! Here's a link that you may find helpful : http://www.dansmc.com/buzzbox.htm HTH - let us know how you get on.

For the unconvinced :- There you go............. Picture page 40 of Don Morley's "Spanish Trials Bikes" ISBN 0-85045-663-0 (pub. Osprey Publishing Ltd. 1988)