Bultaco

I purchased a Sherpa last year with the intention of restoring as I have done a fair few in the past. I am just looking for a little advice as to the definite year/model as there are a few things puzzling me. To start off the bike is sat in a frame believed to be SM but can not confirm, the original frame is supplied which is numbers matching to the engine. Engine JM-19906685-A Frame JB-19906685-A The Number of the frame the bike is currently sat in is 685, no letters just the three numbers and looks to be chrome. Also the bike has what I believe to be an airbox mod which was throwing me off the year and model etc. After some research there seems to a airb…

Proud owner of newly acquired 71 Bultaco Sherpa T 250 (seller said it was a '71 but I have not fully verified yet) First question! It's about the petcock, which I think the seller gave me incorrect info about...After some testing I believe the pic below is the "off" position (lever at 3 oclock, aka, pointing at right hand side). Is that correct? And "on" would be straight down (6 oclock) and reserve pointing at left hand side (9 oclock) ?

My Model 85 is finally running after much advice from many of you. Hearty thanks to all of you! I'd like to know what gasoline-to-oil ratio you have successfully used in your bikes. I'm seeing everything from 40:1 to 100:1 recommended for two-stroke motorcycles in general. I'm sure that covers everything from pit bikes to high-level motocross racers. What actually works with the trials and trail bike Bultaco engines? My bike will be used in an amateur video production, so very low smoke output is important. What works, gents?

Hi My M159 is all restored with new seals, bearings etc, etc. The only moving parts not renewed are the piston/rings/bores (loads of compression and fine in my opinion) and the swing arm bushes (not a problem). Apart from that its all new. I've fitted electrex ignition which is timed correctly for this model I believe (2.9mm BTDC) checked on a strobe and it starts on choke very easily. Everything is very smooth and lovely, BUT, in order for it to tick over correctly once warmed up it has to have the mixture screw wound all the way in! If I try backing it out at all (1.5 turns out is standard) it coughs and backfires even at 1/8th turn out from fully seated it starts to…

I've got wheel alignment problems with my Model 159, even after straightening the bent swing arm and triple clamp. I've measured and drawn up the swing arm and cast aluminum rear engine mount and it sure looks like the engine case center is supposed to be on the centerline of the bike with the swing arm centered on it too. Yet with good sprocket alignment (fresh sprockets too) to get the rear wheel aligned on the front wheel the rim has to be pulled over towards the sprocket to the point where I've got serious concerns about the amount of thread engagement between the spokes and nipples on the right side of the wheel. Perhaps the new Buchanan spoke set is off, with the…

Hello, I've decided to replace the original Amal on my M116, 325 Alpina with a Mikuni and have bought one from In-Motion, along with the manifold. I have just tried to fit it and there isn't room for the retaining nuts at the two studs are practically touching the rubber manifold. I thought I'd ask in case anyone else has found the same problem and how they resolved it. I suppose I could cut the rubber away but don't really want to do this in case I damage it too much! Also, should I keep the original rubber carburettor spacer or remove it as the new manifold is rubber? If that is the case, I assume I will need a paper gasket between the new manifold and th…

Hi I an running out of patience with the Amal Concentric. To explain the background on my ground up rebuild my target was to get the bike original in all things. To this end I purchased a new Concentric Mk 1. It is Jetted correctly runs realy well when the engine is warm and then always starts first time. However when cold it is B**** and needs 20 - 30 kicks to get going. It tickles up with fuel over flowing so there is no fuel shortage. Sammy Miller, James @ JHS racing have told me I am wasting my time as the cold staring design is poor, and to get a Mikuni or DelOrto, well ok that may be the route. But surely Bultaco would not have put up with this problem when t…

Finally managed to get hold of one at last its in bits (engines ok) but the frames had all the braze on fittings ground off it. If anyone would like to measure me the length of the chain tensioner bracket from hole to swingarm and also the distance up from the swingarm pivot to the rear cable stop I would be pretty gratefull. I`ve already fitted a montesa type head steady as I`ve seen a few with this mod and the ht coil had been moved further back down the frame, but I cant think why. Its also had some work done to the rear shock mounts as they`ve been rewelded on above the rear spindle to make the shocks lay over. I was going to put them back to standard but think i`l…

Hy boys I was always wondering, how much better a more modern than the 40 years old Amal 627 carb would be on my M49 Bultaco. After succesfully fitting an Oko to my Honda TL 250 (ok, quite similar to the Keihin, as it is a copy, but was tricky to find out the good jettings), I did it again an bought for 80$ form ebay (Taiwan) a 24 Oko. I once read an article in todotrial, comparing Oko and Mikuni to a modern GasGas 250, main jet 120, slow 45. This is my starting point now in the 1968 M49 Bulto. Has anybody experience with an Oko and jettings on a Bultaco? Any advice is welcome, as it could be time consuming and frustrating to try & error... (On my TL 250 4 stroke …

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 …

I just replaced the brake shoes to my Bultaco, got replacement ones and installed them. when I mount them without axle all seems OK, there is some space so they should run free. BUT when mounting the axle they don't fit the pads slide very strong. Some options: - mill away a mm or so on each side of the supports to the cam, (they look thicker) - mill away the sharp edges at the beginning and the end of the linings? - get another pair of shoes that fit - ... Any better or other suggestions how to align the lining so they fit again. It's "difficult" to see where the problem is. By the way the axle is not bend!

Hello, I just bought my first Bultaco its a 1973 Alpina 350. I usually don't buy non running bikes, but this one was in such good shape I went for it. The PO was an older guy who was the second owner. The first owner was his long term friend. I remember seeing spark when I bought it and the compression seemed good when kicking it over. I rebuilt the carb and was hoping to hear it run, but now it doesn't spark. I attached some pictures, because I know you guys like pictures. It has a headlight, taillight, brake light, and kill switch. I don't know if they are stock or aftermarket. My first move was to clean and tighten the wires going to the wire connector block.…

Hi Guys Can anyone help or advise with my non running sherpa 350 199***** It used to start up 4/5 kick and run ok. I was out on it at the weekend and it started to run rougth. I thought it was running out of petrol so went for res but made no diffrence. It then would not tick over and stalled three times on the way home finally giving up all together, and had to be recovered. I thought it felt like fuel starvation so stripped the carb,cleaned it and blew out with air compressor and re built. Still wont fire, tried bumping down hill and still wont go. New plug with a nice bright white spark but no joy. Have re stripped carb fitted with new slide as there was a very sma…

hi help with bultaco Sherpa 350t 151 model can any one tell me how many cc of oil for gear box and what oil is best how many cc of oil primary drive and what oil is best and also how much oil for fork legs and whats best sorry for questions its my first bultaco I was a ty man before many thanks

This is my first post on this forum but I have been viewing the topics on the board for about a year. I own several Bultaco's and I am very knowledgeable about the brand and many of the models they produced. I have been riding an M159 Sherpa for the past 5 years in vintage events. This past year I have been using it in the vintage class but we ride junior type sections. Myself and the other vintage riders find the junior sections more than manageable on the older bikes. Last year I got an M199B sherpa t and I am just now finishing off the restoration. I use that term rather loosely as all I have done is blast and paint the frame, new tires, new cables, brakes, and a…

Hello, I'm fitting a new piston kit to my 159 350 and I have had to fit 3 base gaskets to get the piston height correct.Is this normal?It's a mahle piston. I've also had to machine 2mm from the exhaust side of the skirt as well.My bultaco dealer said I may have to modify the piston. So I just thought I'd ask if anyone else has had to carry out these mod's while fitting a new piston kit. Thankyou

Hi Lads, looking info from someone who has experience in these little bikes. I am trying to put it together for a friend who dismantled it years ago and put it into boxes with other bike bits that are not for this bike. I got a gasket set, no head gasket in it, does it need one?.How much oil in gear box, and where do you actually put it To be honest the only reason im building it is, it was the first Chispa made and has the matching 001 numbers. Any info on this little bike would be very much appreaciated, Many Thank's

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…

First bultaco I have purchased. When i done me homework and realised how it was meant to look I knew what had to be done ? Cheers to the guys at Inmotion (Bultaco uk) for the advice and parts.

Hi, I've just bought a 1977 Sherpa 350 with a mikuni carb. I've cleaned it thoroughly as it was leaking from the overflow pipe. Does anyone know the float height setting? I have it running but not easy to start and it dies like it's out of fuel after just a short run but starts again after. The air screw is only about 3/4 turn out and I've seen elsewhere it should be 2 turns out. Can anyone confirm this? Cheers Neil