lorenzo

Thanks, mcman56. Can't see why universal regulator should not work on an Alpina. LSMO - I don't have any accurate means of measuring resistor/diode performance. Is polarity an issue ? - this is AC, after all. Additionally, if I understand its function correctly the resistor/diode affects only the stoplamp / LT igntion coil circuit. I believe there must be other ways to provide a stoplamp : LEDs and a small battery, maybe ?

There are also wiring schematics on this website : - Here's one I posted earlier (this is a scan of the appropriate page in the owners manual) :- This is not very clear ; here's another in Spanish that you should be able to make sense of :- Says Sherpa T, but wiring is exactly the same. Hope this helps.

This may help. Free download available here : - http://ossaengineering.com/wp-content/uploads/2014/02/OSSA-5-speed-manual.pdf which covers 250 Plonker model. otherwise Google "Clymer Ossa Manual"

You have a spark - good, you're getting somewhere. Wires in the pic. appear to me green, yellow, and black with a white tracer - in which case, not original. Yellow is normally connected to lighting coil. Is the lighting coil present ?

"3 wires from the engine" - what are the colours of these ? I'm assuming red, green and yellow. If this is the case, the black? wire from the HT coil should be connected to the red. Green (originally feed to stoplamp switch) needs to be connected to a reliable earth. Yellow you can insulate and ignore - this is the wire from the lighting coil. This applies to the original Femsa wiring.............which may have been altered in the last 50 years. The foregoing is simply to provide a spark and get the engine running. HTH

These resistors were o.e. fitment on several Bultaco models supplied with direct AC lighting, including many of the Sherpa ranges, and were I suspect relatively common. Could maybe have been used by other makes, too. Unfortunately, the availability of genuine Femsa parts has long been in decline. You don't state your location, but as with most other old bike parts, eBay is your friend. Leastways, that's where mine came from...........

Resistor is a proprietary Femsa item RSA1X-7 (Bultaco pt. # 85.21 - 217). If you simply want to get the bike running without stoplamp function, just connect the green wire to a reliable earth/ground. This will enable the mag. to produce a spark.

Hi, Ellessemo - Welcome to the Bultaco forum. Just checked a couple of mod. 85 resistors with analog multimeter. They both measure 4.7 ohms across the tags of the actual resistance; one measures 22 ohms, the other 25 between the spade terminal on the green wire and the frame mounting bracket (earth/ground) i.e. with the diode in circuit. Can't vouch for the accuracy of my meter, mind you........... HTH

atitagain - As you have a later swing arm, I wonder if you also have a later rear wheel (17mm. spindle, rather than the earlier 15mm.) ?

feetup - My 85 is a late one - well into the 6000's, and has the same details as your later one. Bultaco went to welded-on footrest mounts ser. # 2328 onwards. Not sure about the recessed s/arm pivot or steering lock fitment, although addition of a steering lock took place on contemporary? Sherpa model 91 quite early on in its production. Rearward chain tensioner and chain oiler swing arm from ser. # 2546 onwards. This information from Bultaco parts listings, not from personal experience of examining every Alpina 85 ever made, you understand..... Does it agree with your actual serial nos. ?

atitagain - Model 85 had a roughly 4-year production run and underwent many detailed changes. Your gearbox if original is more akin to Sherpa 91/92 than model 80 ; I believe all Alpina mods. 85/97/98/99 had a spline-fitting clutch centre from the outset. It follows that the mainshaft and layshaft are the same as Sherpa 91/92, as are the two 5th. gear pinions. (Mainshaft bearing at the clutch end is same as 91/92 at 17mm. i.d.) The 13mm. /14mm. change that woody mentioned took effect on the other end of the mainshaft, i.e. also affecting the sleeve gear (5th.) and its bushes. Again, if original splined shaft this won't be an issue. You could simply replace all the intermediate pinions with a (secondhand ?) set from a Sherpa 91/92, retaining your original mainshaft and layshaft and 5th. gear pinions, if desired. As far as I know, the selector forks will also interchange. All of the above - unless someone out there with practical experience of this conversion knows differently, of course........ A gearbox strip will determine what's needed, anyway.

stpauls - In my experience, doing anything to these old heaps is likely to turn out expensive. We don't know how much elbow room the o.p. has, pricewise.......

You say "I'm inclined not to think it's a 125 with a Sherpa engine". Yes, you are quite correct. What I meant to say was you have a 125 Alpina with a 250 Alpina engine - apologies. In basic nitty-gritty essentials, that's a model 80 Sherpa. I note your bike also has a later swinging arm with trailing tensioner - an improvement over the earlier type. A long time ago (pre internet & access to online info.) I also bought a 250 Alpina, believing it to be a Sherpa..........

Yes, Alpina & Sherpa share many features. Your bike is an Alpina 125 with a Sherpa Alpina 250 engine. The tank/seat unit is Alpina. Sherpa tank/seat unit is very similar, but slimmer and with shorter seat. Front mudguard bracket is a Sherpa item of approximately the same vintage. Gearbox internal ratios would differ from those of Sherpa originally. Exhaust silencer originally would have been mounted lower inside frame tube (where it wouldn't burn your calf or set fire to your boot leg) on both Sherpa and Alpina. Change the tank/seat and the gearset and virtually you have a model 80 Sherpa. Good luck with whatever you do with it.

Why not clean the existing tap ? Beneath all that green-coloured rubbish in the slotted part of the tap (shown in the lower part of your pic.) you should find a fine mesh screen. Wash it out/ blow it out with an airline, if available. Try using a carb. cleaner aerosol, maybe.

As stated earlier by bullylover - As an aside, I'd be interested to find out when water cooling and hydraulic clutch operation happened........

Fabrice - Don't worry about your bad English, it's "parfait" as far as I'm concerned. And that's a very nice looking Alpina............

Tonyd - Numbers indicate Mk. 2 Metralla frame and (later) Astro 250 engine.

feetupfun, your 198 cylinder is stamped 165, possibly ?

Ninja - + 1 on woody's comments. If the leak persists, check that the gearbox breather is clear. It's a small hole high up on the left crankcase, just forward of the fixed end of the kickstart spring. If this hole is blocked, some have found that this can cause an oil leak from the gearbox or worsen an existing one, especially when the motor gets hot. (The air inside the gearbox will expand with heat, and it has to go somewhere, I suppose..........) On this 199 engine I've pushed a piece of wire into the breather to make clear its position :- HTH

Would be easier to fit connecting link at rear sprocket.....is the chain in two (or more) pieces ? What's happened to chain on lower run beneath brake arm bracket (bottom r/h. corner of pic) ?

Hi - Yes, it's a Cotton, probably Cavalier model about '69 or '70. Should have a frame no. stamped on headstock, which will help to identify it positively. Here's a similar one I owned back in the day :

Hi - You need to find a way of locking the engine/stopping it turning, Put it in 5th./top gear and apply the rear brake hard while attempting to loosen the locknut. HTH.

The spacer in reality is narrower than it appears on the drawing. The frame bracket provides an ideal "chute" for the spacer to roll down and out (to get lost) when the bolt is withdrawn....... Without the spacer, tightening the bolt will possibly deform the frame bracket and makes the bolt likely to come loose. .......and can give trouble even when all fixings are tight.

When you fit the head steady, make sure that the spacer #138.10 - 119 (no. 39 in the illustration) is in place on the frame fixing bolt , otherwise it will not tighten correctly. This spacer is easily lost.........