woody

The 350 MAR was produced from late 1975 so it has the later type shafts for kickstart and gear lever. It will be the same spline as the enduro engine, assuming no-one has changed parts on it at any time. Just count the number of splines and compare to double check

Same for all models, they changed the gear and kickstart shaft sizes around late 1973

Yes, you'll need another kickstart and gear lever with the correct number of splines, the earlier engine shafts have more splines than post 1973 engines The exhaust won't be a straight fit, yours has a flange held in the cylinder by the threaded screw in collar. The exhaust on the enduro engine is a push fit held with springs. To get yours to fit you have to cut off the flange so it pushes into the cylinder and weld two hoops on it to locate the springs - as long as it is the right diameter to fit. But how the enduro motor will run with the trials exhaust I wouldn't know You also need a carburettor, yours won't fit as it is bolt on and probably also too small for the porting, whereas the enduro cylinder is a stub fitting

The stator can be checked, you'll need the workshop manual which will give the expected readings, I've no idea, electrics are a mystery to me. In the UK we can get them repaired. The motoplat coil for the Ossa is a combined coil / cdi so you need the two connector type. New replacements are available (at least here in the UK they are) When I saw the picture of your replacement engine I assumed it was the same year as yours but someone had changed the cylinder head for a later one. It seems the chassis number list I have incorrectly lists the engine as a 1972 but it's actually a 1976 enduro version, so, the kickstart and gear shafts have a different number of splines from your explorer engine. I think that the exhaust fitting on the later enduro motor is push fit with springs, not threaded collar, so your exhaust header isn't a straightforward fit To be honest you're probably better off fixing your explorer engine, all parts are available.

The centre cases are all the same casting so are interchangeable. The reason the ignition cover might look different is because the rear most part sometimes gets cut off or modified, either to stop a build up of mud or they simply get broken by derailed chains The replacement engine is an enduro engine, the Explorer is a trials engine. The enduro motor will have a different state of tune/porting and different gear ratios. They also use an expansion chamber motocross type exhaust although your Exporer exhaust should still fit into the cylinder. They use a 32mm carb as they're basically a race engine It's not an uncommon problem to find a different engine won't slide into the rear frame mounts. You might find that the mounting brackets have been squashed inwards slightly with repeated tightening over the years. You can try puting a piece of solid bar against the inside face of one and putting a solid bar through the hole in the other and tapping outwards, then repeat on the other side to try and open them out a bit. Or just take a bit off the engine to enable it to slide in

In the US you have Hogans, Alex Snoop, Keith Lynas, Vintco

The retaining nut is almost as big as a 10 tooth sprocket which means the chain rides up over the points of the nut when it is flush against the sprocket. To use a 10 tooth there is a nut with a shoulder on the inside to give clearance to the chain, you need to use this nut Depends where you live, in the UK, In Motion have all you need I run a dished rear sprocket on my MAR which only comes in 44 tooth size, this works well with the 10 tooth front

It's a 1972/73 Sherpa, the model number is 92. The frame/engine numbers are close because the UK importer used to sell them as 'kits' to avoid purchase tax, so when the bikes arrived from Spain with engine and frame numbers that matched, the importer removed engines and then sold a bike and engine to the customer as a 'kit'. It's a Bultaco frame, series 2 type 92, no idea why the top half looks chrome, the rear shock top mounts have been lowered to make them more angled. The tank is a UK made item as using the original Bultaco fibreglass tank on the road was illegal at the time as fibreglass tanks were outlawed, so UK bikes could have these fitted

An Ossa TR77 can't be started with the clutch pulled in as it doesn't have primary kickstarting

Sorry I'm useless with electrics so no help with testing electrical components. The 5 speed manual is available to download which should have readings in it. Or you can send the stator and coil to Bradford ignitions as he can test and repair Motoplat stators and sometimes coils If your wires still come out from the bottom of the ignition casing and run under the engine, there's a chance that they may have got chamfered or broken as they have to bend a sharp 90 degrees, once old and brittle the sheath can crack causing shorts or they can just break. Also, with a bike that's used hard the bash plate gets smashed up towards the engine and can help break the wires. A mod to stop this is to drill a hole through the top front of the casing by the engine mount and run the wires behind the stator, through the hole and up the front frame tube. This involves grinding away some of the ribbing behind the stator to accommodate the wires. If your bash plate has go bent upwards, also worth checking that the head of the sump plug bolt isn't exposed as that can end in tears if it catches a rock. Tapered headless allen bolts solve that problem

The end float on the gear shaft won't affect the plunger as that acts on the selector drum, but too much end float on the gear shaft means the selector fork is not in contact with the selector drum when the shaft moves too far to the left. Inside the clutch case there are two washers on the gear shaft, normal and wave washer, located by a circlip. These restrict the shaft end float, if they aren't there the shaft will continue to work its way outwards, disengaging with the drum, nothing that a kick with your heel won't solve to push it back in though

If the engine is in the bike, put it in 1st and try just tapping the gear lever into neutral with your heel whilst rocking the bike. If the shimming is making the gear selection a bit stiff it could cause the selector to go straight past neutral to 2nd and vice-versa. Tapping it with your heel should move it just enough for neutral. It's how I get neutral on my 250 as the gear selection is a bit stiff, my 350 gets neutral a lot easier

Not sure what you mean by always in gear, if the box will go from 1st to 2nd and vice-versa you're going past neutral. With the bike in neutral the final drive will still turn due to drag on the gears. Put the bike in first gear, then whilst turning the engine gently pull the gear lever up but not hard enough that it goes straight to second, or just tap it gently up with your hand. Hold the final drive with one had and turn the engine, if the box is in neutral the drive won't turn, if it's in a gear you won't stop the final drive turning. It might take a few goes to get neutral, much easier with the engine in the bike and rocking the bike backwards and forwards I'm assuming the detent plunger is fitted and working properly

Carb for the Jumbo was 28mm, never heard of 30mm fitted as OEM. For a non-reed engine the pilot is 50 and slide 60, needle X2 and needle jet AS272. The delorto should perform fine if it's not worn out There is quite a difference between the reed and non-reed motors in power delivery. I tried a non-reed back to back with my reed engine bike when I had one and the non-reed was pretty flat with slow pick up off idle/pilot before surging and getting lively when the revs came up. Are you mistaking that for lean jetting? The reed engine lit up instantly I've run Delorto and OKO back to back on my 340 Sherpa and can't fell any noticeable difference which makes me wonder if it is just the slow take up of the non-reed engine that is giving the impression of weak jetting below 1/4

Whether it fits depends on which Sherpa you have which you haven't mentioned. A Sherpa seat won't mate up to that tank very well, if at all

1972/73 Sherpa T 325cc

If you google ossa wiring diagram you will find one - the blue andblack are for the ignition to the coill, blue on the bigger spade terminal if you intend using the lights to ride the bike in the dark, a candle would be a better option. The combination of not seeing something until the last minute and poor brakes isn't something I'd like to tangle with.... Fit some mountain bike lights

You don't say which Amal, but assuming it's a concentric, for a C15 it should be a 22mm which is the diameter of the standard intake. Different bikes won't necessarily run the same on the same jetting so it always a bit of trial and error. There is only one needle for the four stroke concentric of that size which is U1. Problems at high revs could be either too weak or too rich, If it's too rich it can cause the bike to choke on full throttle, too weak and it will gasp/die. Main jet size is normally around 100 or 110. There should be no pilot jet, needle jet 105 / 106 and it must be the 4 stroke type with spray holes. The jet holder is longer in the 4 stroke so the main jet sits lower in the bowl. Slide is usually a 3 If it is a premier type carb the same settings apply apart from the pilot jet which is a different design to the normal concentric, screws into the outside of the carb body opposite the pilot air screw and this is usually the three ring jet There could be other reasons for it not pulling up a climb, timing, cam type, different head with big valves etc

Fantics weren't produced with reeds until the 5 series, last air-cooled monos, which was about '89

Easiest identifier at a glance on the slimline models is that the 250 had a round barrel with closely spaced fins, 350 had a square barrel with wider spaced fins Ebay, facebook marketplace as well as a number of Bultaco facebook groups where you can see items for sale or ask for wanted items In the UK, In Motion have the biggest stock of parts

Last of the 'slimline' models from 1975 250cc. Model number is 150. Fkywheel and front wheel should be easy enough to find, exhaust more difficult

If you mean the production Sherpa N and Matador, I don't know either that well but although the frames share the same basic design I'd say the Matador is more bulky with more bracketry and reinforcement. The Sherpa N looks more bare like the Sherpa T I forgot one word when I mentioned about 669 NHO being based on a Matador frame and that was 'probably' I guess it could just as easily be based on a Sherpa N, which, thinking about it, seems more likely. It is known that the frame number of NHO begins with a 4

Yes, not just works teams either. The first 5 speed model 27 he had used the same plate as a later 4 speed bike. The original 669 NHO wasn't a Sherpa T as such as the T didn't exist at the time, the frame was a modified Matador, which is how the original NHO frame can be identified, from the mods and welds

I've never seen anything that gives information as to specific serial numbers for V1 and V2. It seems plausible that 1 - 479 are V1 but I wouldn't know for sure. The chart also says '1er' model for both but I'd assume that means 1st version of the Sherpa T. No idea what the reference to USA and Spanish versions are, the serials numbers don't carry a suffix A or N on the bikes and I think most were sold to the UK anyway. The features of the frame are likely to be the best identifiers of V1 or V2

It was owned by a private individual for years then sold a few years ago, where to I don't know