mrb505

They are both 3.6x230mm although the head or and the angle may be different, you’d think the part number would the same if there wasn’t any difference. That 86 number is the part number for m91/92 front inner spoke as well.

Yes that would fit, that photo is of a m151 with a pommy tank, the 150/151 had the 1st head steady and a improved headstock gusseting

That is a 91/92 series 2 frame I believe, that small gusset is standard on them and 124/125 frames or the ones I’ve seen anyway. The difference between 91/92 series 2 headstock and 124/125 is the waist between the bearing positions on the 124/125 the photo is a m125 headstock

My late model 49 has a G stamped in the same spot I don’t know what it means but we could always make up a story that it means Works Super Special but really it probably means George stamped it as it left the factory Looks to me your original frame mounted sidestand bracket is on the right side if the swing arm bracket is on the opposite side the bracket would have been welded on later I’m pretty sure no Bultaco had a stand on the chain side Those mounting lugs are interesting are they buffer mounts like the ones behind the headstock you’d have to wonder what sort of tank/seat it had on it. They are not even opposite each other.

There is a o’ring behind the bush the sprocket seal runs on that should be done while the seal is out too.

Yes it’s a 183 frame when I bought it the tubes underneath were totally squashed so I cut them off and tried to replicate it to a 199a style, the bash plate I bought from todotrial I also cut the foot pegs off and mounted gas gas ones a bit further down and back

The problem is that I clear coated over the sticker I’ll redo the tank maybe one day but the bike isn’t very original anyway and as it’s a regular rider it wears a plastic tank most of the time

Nice job XXXX looks great I put the smaller Bultaco sticker on my 183 and it’s annoyed me ever since

The sticker kit is a generic one and most Bultaco parts suppliers will have the same ones Peter at http://www.bultacoaustralia.com/ would be able to supply individual original ones

If you want it authentic a 158 shouldn’t have a sherpa sticker on the tank pretty sure they had the 1975 world champion sticker instead The sherpa sticker is from 198/199 models yours should have the round sherpa t on the side panels I’m not too sure if your model had the made in Spain sticker either If you bought the stickers in a kit you’ll probably find the the Bultaco tank sticker smaller in height and length than the original, in those kits they are 198/199 size Heres a link that has original brochures https://www.motoguapa.com/BULTACO/ArchivosBultaco4.html posted before seeing XXXX,s post that tank looks original so made Spain sticker was there

That’s interesting David is there much visual difference between the hubs

Woody is right they need a short length of pipe welded to the inlet about 11/8 od x 11/4 ish long They are louder but I think a much nicer sound the reproduction ones seem a bit louder than the original bananas I have a reproduction one on my 183 and a cleaned and repacked original on a 125.

Being a 49 it wont have the slot I think all the solderless nipple bikes don’t have a slot

I bought a new set of Bultaco betor forks with clamps out of the US a few years ago still in the box they were stamped Bultaco but the same style clamps as SWM / Italjet I guess unclaimed from the broke company

Have heard money was tight and they using up what stock they had left in the end

Wasn’t being a spark arrester the only reason the club foot came about, so they could be sold in the US. I think the banana performs better let alone being half the weight

I think the 158 182 190 tubes are only about 10mm shorter but the rods are also 10mm shorter as well so they use the same length springs as the 350’s of that era or maybe even all Sherpas Id probably just cut those 500+ Pursang springs down to a suitable length All the sherpa springs I’ve measured are between 450 to 475mm long

M10 and M27 header pipes have the same part number but I'd guess they were tweaked a bit or more in the factory to fit individual bikes https://www.inmotiontrials.com/product/bultaco-sherpa-4-speed-exhaust-front-pipe/

Should have 2 8x20x62 studs in the barrel but 8x45 bolt should do with the header pipe I'd be getting one made up for your bike all the header pipes are slightly different even for individual models so for a 27 in a 49 frame I doubt you'll get one that will fit nicely

Going by the parts books I have they were fitted from m10 up to 1331 in the m80 production run Early m85 Alpina s had them as well but I'm not sure when they changed

Try to get a copy of this book https://books.google.com.au/books/about/Bultaco_Limited_Edition_Extra_1971_1979.html?id=FZdVAAAACAAJ&redir_esc=y&hl=en there is a cycle world test of the m187/188 that they claim the only difference to the m165/166 is the paint scheme. Has a good spec list of it. there is a few other Alpina tests in the book from the day

You'd be better off asking about model number differences like m138 years don't really identify Bultacos ive never seen individual Haynes manuals your probably after Bultaco parts books here's a m212/3 link to one http://www.custgp.com/a1manual2/Bultaco Alpina.pdf

Woody I'm pretty sure all the 325's from m125 on had the same flywheels around 2.8 kg on both sides your 159 may have been modified if it had a pursang primary flywheel

If your talking about ignition side you might not want a m49 ( VAR41-9)flywheel about 2.4kg against 2.8kg that you probably have now (VAR41-52)) where as the 250 later flywheels (VAR41-51) m124 on are around 1.7kg. Well that's from my scales they probably vary a little bit. A lot of 250/350 Alpinas (m137 on I think) had the VAR41-51 flywheels so it might be easier to find one from a Alpina as there seems to be a fair amount of Alpina parts on eBay in the states.

Part no.49.00-068 for frame no. up to 1832/ part no.80.00.068 for frame no. 1833 onwards