d250b

Thanks Derek pm sent?

Deary me.....that’s unfortunate. I hope it’s a false alarm and they’re all ok. Thanks for letting me know Peter

Thanks Scot Taco, yes the 250/360 are same part number it’s just there seems to be a lack of Mk7 in general. I’ve tried InMotion, they didn’t have a Mk7 and I was waiting on them getting back to me with some info as to other marks being a possibility. Hope to hear from them soon but they are extremely busy and I didn’t want to miss out on Something which is for sale just now and may be suitable. If I can’t get a suitable basket it puts the whole rebuild in question....there are brand new ones being made in Spain but Mk10 onwards. The options all seem to be either Spain or USA and if it have to buy from there I want to be 100% sure it’s the right fitment before I buy. Cheers D

It’s an alloy basket that’s been removed from the bike, and I have absolutely no idea if it should be alloy or steel I just assumed they were all alloy, thanks

Hello, I’m hoping that some of the depth of knowledge on here in the trials world might branch out a wee bit! I am trying to find a clutch basket for a Mk7 Pursang, 360cc, model 121. I can find examples of new and used baskets for other marks but not for the Mk7. I understand that there are subtle differences between the models but I do not have knowledge of what these are. I am hoping that someone might be able to tell me that a basket for a Mk6 might do the job for example? I’m also unaware of whether there are differences between the 250 and 360. the old basket removed from my Mk7 is a 38 tooth duplex with an overall outside diameter of the basket of 118mm and the hub bore is 52mm to accommodate the bearing. Be most grateful of any information which might help! D250B

Hi Karl, you perhaps know this already but there's a Bultaco-specific forum further down the page where there are lots of very knowledgable and extremely helpful people!! Buy them both and give them a new lease of life its a satisfying way of emptying your bank account! D

Hi big_e, might be able to help with your number plate, i got one from ebay-pre curved for my model 190 and it fitted a treat. I haven't even road registered it but wanted the number plate on there anyway. unfortunately the link to the ebay item doesn't come up with anything but I think this is the company that sold them: D & C Classic Motor Cycles - Ickornshaw Mills - Ickornshaw - Cowling - BD22 ODB - Tel: 01535 630137 I also ordered the numbers and letters to stick on from ebay and they came from a company called 'snappygrafix'. (they have their own website by same name) they were very obliging and even managed to do me the font which was in use around 1977 when the bike was new! DVLA have changed it over the years and there are subtle differences and I thought it would be good to be authentic. The plate was only about £14 and the letters/numbers only about £4. hope this helps. best of luck with your rebuild! D

Well I've given up on the bespoke gaskets, going to be too expensive to order a few plus postage and I'm quite sure when they arrived they would be 0.8mm thick! The same company has big sheets of 2mm thick gasket paper on ebay for £16 quid in material suited for oil and ill just order some of that I think. Looked at a cereal packet and not thick enough to give me the 2mm. Yamabond looks interesting Woody ( I wonder; if it's a better gap filler, if it might have worked with the original gasket and saved all this hassle???) and thanks Matador107 for the suggestion of how to cut the gasket, that's pretty clever. Cheers D

Thank you! it may, after all come down to a rice crispies packet...i was a bit previous with my last post. Despite having explained clearly over 2 or 3 emails what i needed and also putting a letter in with my original gasket to CLEARLY say that I needed the new ones 2mm thick, I got an acknowledgement email yesterday to say they had received my original and that they would make the new ones out of material 0.8mm thick also although the gasket price was now cheaper at £7.47, the postage had suddenly gone up to £18 from a tenner (apparently the £10 quoted on the website is just for stock material NOT bespoke jobs). I replied explaining that 0.8mm is no use and the reply to that is that they can do 2mm no problem and the price is the same as "material thickness is nominal". No idea what to make of that. Ive also looked at the material they were going to use and it looks like its for high temperature situations and it "generally exhibits good resistance to oil and fuel". Doesn't sound all that great does it? I think it would be easier to just ask for my gasket back and forget it and make my own. Seriously; I'd love to put a transcript of the various emails on here just to show you how difficult it seems to be to specify you need a 2mm thick gasket but Ive rambled on enough. Greg, in all honesty Im not sure that I wouldn't have enough clearance with an ordinary gasket; I just though I was doing the safest thing by recreating the original clearance with a thicker one. Maybe I could stick 2 ordinary ones together with some blue hylomar and that would work?

Update on progress in the hope this may be of help to anyone in a similar predicament. I rubbed and rubbed and rubbed the casing down on sheets of emery cloth until I got it flush all round. Pane of glass on the desk, taped down and emery cloth taped to that. I've found a gasket manufacturer who will do bespoke designs and i'm going to get some made in 2mm material; they're only just over £10 but the postage is a tenner too so best to get 3 or 4 to make it worthwhile. Hopefully this will sort everything out and maintain the clearance on the casing with no problems and better than sticking 2 together. Not sure about any rules regarding advertising on the forum but should anybody want the company's information, please fell free to PM me. D

BultacoUK will do you an exchange on your coil. Order a new one from them and send them your old one, check their site for cost but iirc it wasn't too bad, nor was the cost of a new loom. I removed my lighting coil too and went back to a single coil. There are diagrams on here somewhere if you do a search. D

Thank you for the further replies; the welding repairs I had done to the Sherpa, including the clutch case went extremely well and there was no bubbling up from oil in the alloy so for some reason the Sherpa casing hadn't absorbed oil the same way? ( it was almost dry of oil when I took it off but I don't think it's as simple as that:-) ) if I need any repairs of this nature done in the future I will certainly take all of this information on board and hopefully if anyone is searching for this topic in the future it will help them out. After a lot of deliberation I have decided to try to rub down the edge of the casing on sheets of emery cloth on a flat surface ( no luck finding someone who could do milling) and then make my own gasket out of thicker gasket material to compensate for any reduction in clearance. I am going to try a "putty" type repair on a broken flange on the main engine case; on the magneto side underneath the front sprocket and similar to the repair PSchrauber photographed above. Hopefully I can manage as good a repair as he illustrated, it's on a non-critical bit so a good place for a first attempt. I'll post pics of repairs (good or bad) once I get some time to tackle them. Cheers D

Thankyou all for the replies and suggestions, theres a lot to think about there, just have to make a decision about which path to go down. The blacksmith who did the original welding and who made an excellent job of the Sherpa, is reluctant to go at it again because he's really annoyed about what happened. This makes me lean towards the epoxy/putty idea for simplicity. Ive watched a youtube video for Pschrauber's Knetmetall and it looks pretty good; I can get a small tube for about £11 so its not too pricey either. (is that water/aqua blast finish on your casing? looks very nice) The youtube video is all in German but I take it you just work it a bit in your fingers to warm it up and then apply, no hardener or anything? (The loctite needs a hardener) I also have a broken edge like yours which I was just going to leave but having seen your repair I think I should do it too. I'm not aware of anyone with a milling machine but there are so many garages and motorsport people round here theres bound to be someone that could do it. It is the older more rounded sort of case with the proper drain plug and the filler at the front and there seems to be a few available in the US but I'll leave that as a last resort but I want to keep the bike as genuine as possible. Perhaps the path of least resistance would be to try one of the puttys first before milling or rubbing down, I just hope that putting a rough surface on the edge doesn't require removing so much metal that milling down won't leave me with enough clearance.....to be continued Thanks again for all the replies, much appreciated! D

Hi All, Having had a welding repair done successfully to the clutch casing on my M190 Sherpa a wee while ago I undertook to get the same thing done on my new project (M121 Pursang). (Bultaco fetish? ) Unfortunately the alloy on the Pursang behaved rather badly; I understand that some of the alloys can be a bit porous and absorb oil over the years and this flares up and makes a mess of the weld? Anyway the welding proved problematic and it was a much bigger job than it should have been. It appears that the heat has warped the edge of the casing and as you can see from the photo I now have a small gap, probably about 1mm deep and 5-6cm long on the bottom of the casing. I've had it on the bike with a new gasket and plenty blue gasket sealant but she leaks....so I'm really disappointed. Just wanted to get some opinions on the extent of the problem; can this be remedied by putting the casing on a flat surface on a big sheet of emery paper and rubbing down/is there another solution/or is it knackered?? Would value some opinion/advice. (Apologies if its not the done thing to ask about a scrambler in here but there doesn't seem to be the level of information out there about Pursangs as there is on the Sherpa or a source of knowledge anything like there is on this forum. Is there anyone else out there who has a Pursang in their Bultaco stable??) Cheers D

Pschrauber, forgive me if I'm wrong but isn't the Aspen R fuel an ethanol blend? I have used Aspen 4T and mixed my own oil for the Sherpa and it seems to run very well on it; I myself have very little knowledge but others who have; thought the bike was running very sweet. I have not changed any of the jets in the carb but then again I couldn't tell you with any certainty which jets are in it. I believe Aspen 4T is 95 RON but I also added Putoline Octane booster. I have just acquired a Pursang and will try it with Aspen first to see how she goes. I also use neat Aspen 4T in the lawnmower and it runs well. I use pre-mixed (50:1) Aspen 2T in the chainsaws and brush cutters etc and I think Im convinced its ok; had some issues with difficult re-starting on a brush cutter to begin with. one thing to mention about the pre-mix is it makes you think the engine is running really hot from the smell it gives off; I was assured that this is just a product of the type of 2T oil they use combusting and I have to say you get the smell immediately after starting up so the engine hasn't had time to overheat. It is very expensive but I started using it mainly for the perceived benefits over ordinary petrol and since the filling station in the village has now closed it's also more convenient just to nip to the chainsaw dealers and get a can. STIHL have now started marketing a version of their own in competition to Aspen but it's even more expensive at the moment

Coriolis effect/Southern hemisphere thing going on?...... EDIT: beg your pardon; my lack of knowledge didn't allow me to think that deeply about it! I just thought it was the mud guard on back to front

Thanks Larry, I've no doubt that the paint job will fall victim to a lack of skill sooner rather than later!! Bondy I started with a 100mm bolt to accommodate what I now know was a flared front to the tank but I had to cut it down to use the fancy nut so 90mm might not be too far off but your tank will no doubt have a different cross section than mine at the front. You might find you have to cut it down a bit even from 90mm. Only trial and error will show what length you need. I also had to cut the sleeve nut nearly in half to get it to work given the distance between tank and the protrusion on the frame. I believe the star head with the little nipple in the middle is a security/tamper-proof feature and my Draper star drivers luckily came with the recess to accommodate that. As I said though you can get the sleeve nuts without it. D

Bondy I was lucky in that my star drivers had a recess to accommodate the little nipple in the head of the bolt. I did find others which didn't have that feature so if you have ordinary drivers you can still get them. I opted for those ones simply because they were set up for PayPal.

Thanks. Woody I think I'll leave as is, just in case. Knowing my luck I would just bu@@er up the paint! Bondy, the rubber bungs came as a set, with one going over the metal protrusion on the frame and the other one free floating. You can see on the right hand side of the photo that I've put a thin rubber washer in between them to make them a snug fit and to stop the tank getting drawn in by the bolt/nut. I didn't realise at the time that the front of the tank was flared out so just assumed I should fill the void snugly. Now that nothing is fouling on anything else I think I'm ok. It's a plastic tank. You can see on the label in the pic where I got the nut from, they seem to be used in boat building. Larry thanks for the info, I didn't know that ss had a tendency to do that so I will put a wee bit of copper grease on there just in case. D

Thanks for all the suggestions. Im hoping to trial the bike for the first time this weekend and there was no way I was going to get any sort of fabrication/machining done in time since my man with the lathe was too busy. I was trying to think laterally for something which could just 'bolt on' and remembered the special fixings on a desk i have in my 'office'. I think I looked for them as Sleeve nuts and through gradual research discovered they could also be called barrel nuts or interscrews. (I did also find a mention of "sex-nuts" ) Anyway I think it provides a pretty tidy solution and is pretty symmetrical. I had to shorten my long button head allen bolt a wee bit and also cut the barrel of the interscrew approximately in half so that everything fitted properly. The only other thing was to drill out the hole in the tank to 10mm from 8mm to accommodate the thicker interscrew. Success! or so I thought but the damned fork still touched the head of the interscrew. Theres a good few mm of clearance at the other side so I don't know whats going on; I can only assume that the front of the tank is flared a bit (as Woody mentioned) and its flared further on the rhs of the bike. Anyway as per Woody's suggestion I partly filled the recess on the nylon bump stop, refitted and problem solved. Tidy finish and no contact. Bit of a long road for a shortcut but I think it worked out ok. Pics show the button head allen bolt, the head of the interscrew and the assembly prior to being cut to length to fit. attachment=14152:P1040099.JPG]

Thanks Larry/trialsrfun. I should have updated the post re the chain but have been really busy. I bit the bullet and got a new chain (Regina). However, I had to remove a couple of links obviously because it was too long but this got me back to square1; in that at this new length the brake arm fouling the swing arm was again an issue. ( If I had left an extra link in I couldn't tighten it enough). The simplest way I saw to get round it was to file down the top corner of the brake arm. Only had to remove a few mm and it gave me that wee bit extra adjustment. So I guess with hindsight I could have done that with the old chain and saved myself some £!!! Oh well, as I've said its a drop in the ocean now! Larry, I'll definitely look into your solution for the tank. I had considered lengthening the stops but that would of course cut down on the lock. I haven't looked into the half nuts idea either as I've been too busy with work. I've used a button head Allen bolt which means that one side looks really neat and flush to the tank, I wish you could get a female Allen head "button nut" ( if you know what I mean) to go on the other side and that would look smart. I have some alloy blank left from the new axle spacers I had made up so I will talk to my engineering guru and see what he says. Cheers D

Like the idea of the nylon bar and I see it's quite cheap on the auction site. New brake arms are only available from inmotion in the bendy form, no straight ones at all. Decisions, decisions.........

Thanks Woody, that bike looks superb, like the rims. Disappointing about the brake arm because it's new and that was what I was sent as correct for the bike. I honestly did wonder because it was the only bent one I'd seen. Mine was broken at the tips and I assumed that it was a common problem and perhaps most we're replaced with later arms which were straight. I will try that tomorrow and see what happens but I will need to get that rectified anyway. I think that would probably fix it because it doesn't need much movement at all. From memory I'm sure it's a 46 tooth sprocket. I changed the front one because even to my uninitiated mind, first gear was just too swift and I wanted it slowed down a bit! It's a plastic tank. Bike came with 2 plastic tanks and the one which was on it was one of the textured finish ones. Part of my dream was the way the bike looked so the proper tank decals were a must so the other one got the treatment. It was in poor shape having badly bubbled. Neighbour is a panel beater/painter and I gave him the two Ford colours mentioned on here and I'm not even sure which one it is!! It was blasted first and he said he took off about 3mm of old paint! I've done plenty reading about the dreaded ethanol so I'm fully aware of the risk but I've just started using Aspen fuel in my 2stroke machinery so I'm using this in the Bultaco. ( I'm using the 4T Aspen fuel and mixing it at 40:1) so there should be no ethanol issues but I still intend draining the tank and venting the cap just in case. I've discovered that with the plastic tank being wider at the front, the nut which secures it hits the fork stanchion before the fork it's the steering stop on full lock. I've stuck a small foam pad on the stanchion to stop it getting damaged. Has anyone experienced this? I can't see a way around it part from maybe a half nut? I paid for an old alloy tank at the same time but the panel beater gave me a funny look when I showed it to him! It's seen better days. He said he could sort it but I was looking at a bit of £ which by that stage I couldn't contemplate because sorting everything else had just mushroomed. So I think I will try and sell the alloy tank to recoup some money. I'll give you an update when I move the brake arm. Cheers D

I have an RK chain and I don't seem to be able to find 1/2 links on tinternet. Maybe another make would fit but I'm inclined to just get anew one. I assume I should remove it and count the links before ordering a new one or is there a default number for Bultacos? I was thinking that the chain certainly couldn't be old, worn and stretched when it's too tight but I suppose a link might have been removed previously?? Front sprocket is brand new as I put that on myself, went to an 11t down from the 12 that was on there. To my uneducated eye the rear one looks ok, there was an old worn one in a box of bits and it's nothing like that.

Great, Thanks! I'll check the chain and see if there's any name etc on it; I didn't renew it so I've no idea what it is. I wonder if, for the sake of £26 (drop in the ocean now ) I should just get a new chain?? if I did should I get the extra half link with it at the same time. Is there a way of working this out like numbers of links?