Bultaco

Hi guys, I Have recently acquired a 199A. The cylinder head has two spark plug tapped and drilled holes, one pointing towards front and one pointing to the rear. The usual central spark plug hole has not been drilled or tapped. This is different to an earlier 199A I owned. The combustion chamber is also a completely different shape to my earlier model. Has anybody any ideas why this is the case? Perhaps the head is off a Pursang for some reason? The barrel is stamped 199A so that seems correct. Thanks.

Ive had my 198b barrel rebored but the guy who did it had an accident with it and had to resleeve it. Im just wondering if anyone could supply the port measurements so i can check that these are correct. Big ask but someone might have a barrel off for restoration

Hi, the rebuild of my Sherpa 198A is progressing 'well' but I have a question on what is the expected / acceptable swing arm free-play and 'stiffness'. I have replaced the nylon/alloy swing arm bearings and spindle with new items, but find that with the newly powder coated frame and new replacement rear engine mount (all from In Motion) its all a very tight fit - requiring the rubber mallet persuader to fit! The result is that although nice and smooth, the swing arm does not freely move under its own weight (a rough measure I've used on road bikes with needle bearings) but requires some force (approximately a 1kg weight placed on swing arm) to move even without the swing …

Okay, so this is not really trials related but I suspect someone on here will be able to offer some advice. I have a Bultaco, Pursang which I have been building and is pretty much all done, however I cannot get a spark from the Motoplat ignition. The ignition is the internal rotor type 63mm rather than the external rotor trials type. I have taken some measurements and referenced them, the coil and stator both seem to throw odd values. I have tried contacting UK Motoplat both via website and Ebay listing but no reply has been received. I have also tried West Country windings who tell me they cannot repair Motoplat. Does anyone know anyone in the UK that could…

Hey Guy's,I have a 138 I have been sorting out and I am not sure if I have the correct brake light switch? When I apply the brake pedal it extends the switch pin and opens the circuit so when your foot it not on the brake pedal the switch is compressed and the circuit is closed,does that make sense?

Hi all, looking for Ally mudguards for my early M49, obviously I can get them from Inmotion but wondered if there was a ‘more cost effective’ route. Any thoughts appreciated. Also looking for a good used Right hand fork bottom or thoughts on how to salvage a really worn one. thanks , Andy

Advice please, the Sherpa 198A I'm refurbishing currently has 12T front and 40T rear sprockets that are very worn and to be replaced. I didn't get chance to ride the bike before stripping down, so is this a reasonable ratio for a complete novice rider? ⚙️ Cheers!

Continuing the Sherpa 198a strip down last night highlighted a couple more things! Both of the 19mm bolts securing the rear (cast) engine mount bracket were tight (didn't check torque), but there was some play allowing the engine to move slightly i.e. being cast the bracket wasn't a tight fit to the engine mounting lugs. I didn't want to tightened further due to risk of fracturing the bracket. Is this play normal or possible due to wear? Exhaust. Both silences are dirty, rusty and oily but externally fundamentally sound. Theres no indication (ie. welding) that they've ever been opened up and repacked, so can only assume they are as original and so will pr…

Hi, sorry new to Bultacos so I've loads of questions as I strip down my newly acquired Sherpa 198A! My front drum is the 'standard' chrome finish, it is in 'reasonable' condition with a few pits and marks. However, the rear drum appears to have had a steel ring inserted at some point which (possibly due to being unused for years) is dull. Was this a standard modification when chrome wore and/or to improved braking effect? It worked on quick test ride but I've no experience of brakes effectiveness (pedal is on left and rod connected which I understand is more effective than swapping to right with cable). Are ring inserts available for the front drum? And (fo…

My clutch case does not have any clearance and rubs on the clutch centre drum pins and the end of the clutch springs ? Not sure if I have the wrong clutch centre hub,or the wrong clutch case ? Year manufacture 1976.

hi is it essential to wire clutch nuts and how tight should nuts be handbook says nuts should be fully tightened then backed off 3 full turns my lobito 175 has the smoothest and lightest clutch ive ever come across daft question what sort of wire......some can be brittle it needs ductility??? maybe copper ...too soft??? suggestions please

hi i am a new member recommissioned a bultaco lobito 175 new piston new conrod kit new crank fitted by acme motorcycles put crankcases back together gears seem ok got engine going ... problem is fitting gear selector and return spring within clutch side casing if return spring is fitted as attachment photo then gear lever cannot move between 2 "bosses" 1 stationary in casing near clutch and 2 boss on selector back which attachs to pawl mechanism at 12o clock mechanism then held square by casing ......if spring is fitted as photo end of spring will not pass boss on casing any help would be welcome struggled for 2days ..must b…

Hi I'm in the process of restoring a 198 t 1978 . I've been offerd a swing arm for it . The arm has a chain oiler drip screw in it my question is was this Pacific to the year of bike or were they an optional add on extra at the time ?

Another ignition timing question ! I acquired a model 191 Sherpa 350 which appeared to have minimal hours. Needed TLC with a standard piston ( piston / cylinder tolerance of .004.) Cleaned up the bike and carb and put in new set of rings. Getting ready to start but first checked the points and timing. ( Bike ran when purchased ). Points within spec - .016 but when checked timing , I found the BTDC was 6 mm ! Can this be given that the bike nan prior to purchase , even rode it up the street. Am I miss something . Here are a couple of pictures . Any help would be appreciated...

I have two other bikes with Bing carburettors that perform perfectly. my 350 Alpina (1977) however has always been a trifle fluffy on low throttle openings. I have just fitted new needle and jet as part of a service and the needle clip was in the lowest groove, what is the recommend position or is it just suck it and see. Thanks.

Ok guys I’ve read all the old stuff on these frames before posting this,just so you know. But I’ve just bought a load of Bultó bits and one was this frame. In the old stuff it says that this frame is documented In Don Morley's Classic Spanish Trials Bikes book on page 40, Is there anyone out there with this book that could forward the image to me. It’s just that what ive read all Miller frames had a number prefixed by SM. Ive enclosed an image of my frame number, but not prefixed by SM. Basically is it a Miller frame, or a Whitlock frame or something else. Many thanks guys.

Hello all, I have been lucky enough to purchase a 1968 Bultaco Sherpa Model 27. It has not run for 15 years and needs a full rebuild. The previous owners have made some odd modifications such as mounting the stand on the left side and looks like they were going to have the brake and gear change on the right side. At present I am trying to collect the correct parts to put the bike back to original. One item I cannot find is a left side rear brake pedal. I know some new replacements are sold with a serrated pedals like a more modern bike but the original has a solid pad more like the brake on a normal road bike. The length is short being 175 mm…

Hi all, I have been helping a friend rebuild a Model 159 which was bought as a basket case. We have a problem with the cutch at the moment. The arm will not disengage the clutch. It is as if the puch rod is too short. I am fairly confident all the drum, hub and plates were assembled ok. We put the thrust washer in with a spot of grease so it didn't fall before all was assembled and we didn't forget the ball bearing. Looking in the Haynes Manual there appears to be a 'clutch rod extension' It looks like a short piece of pushrod. We haven't got one!! Should we have on for this model? Where does it fit? So at the moment we have as follows - operating arm - pushro…

Anyone help with identifying bike I am looking to purchase. Frame number is :- PB187OD408 Engine number is :- PM 187OD408

Does anyone know where billet fork yokes can be got for a bultaco sherpa 199a and magical progressive front springs aswell