The inner surface is an integral part of the hub. They came from the factory with a chrome plate layer on them which wears out and becomes pitted. The hubs can be relined (Bultaco UK do this service
Its not a bad price for the blast and coating. Just make sure you take everything with you, last time I forgot to take my rear brake pedal so had that done later on.
I didn't remove the outer bushes for the powdercoating as I would have probably mangled them when bashing them out with a drift.
It is possible, on the '03 the bottom clamp is part of the casting of the top yoke.
Couple of solutions:-
[*]Universal mounts to bolt onto these to add a new set of mounts for the FatBars. Fitting these does add 3/4" to 1" of rise to the bars.
[*]New Sherco top yoke - 1999/2000 (Part number R087, Bottom Clamps R072 and Top Clamp R073)and 2007 (Part number 1398, Bottom Clamps 1396 and Top Clamp 1395) on have removable bottom clamps (99/00
Check the frame / engine numbers. VNBS129TR6 is the start of a VIN for a 2.9 Trials built in 2006. Note the year referenced is when the bike was built not what model year the bike is so a 2007 Model could have a frame number as indicated.
The terminal nut should unscrew (it does on the BP5ES anyway). Looked on a spark plug comparison table there seems to be many Bosch plugs that could be the one! This website has useful comparison tables., technical information and also sell plugs! The NGK in question is
Does undo to the left yes. If you've not got an Impact air gun you may will need to hold the flywheel somehow. I've got a flywheel holder but before I have had to put the bike in gear, hold the back brake on and then loosen the flywheel nut. Sometimes this has to be done by giving the ratchet handle a belt with a hammer. There are other ways to "lock-up" the engine such as feeding a length of rope into the cylinder via the spark plug hole when the piston is on its upstroke.
A flywheel puller with a thread diameter of 30mm and a thread pitch of 1.5mm. This will fit all Sherco two stroke trials models, many older Montesa Cota, and some Beta models.
Thats not a 1973 model.. Looks like a 198 from circa 1980. I don't know how people can get these wrong (when advertising) there are a load of sites that have all the model codes and the corresponding years on the web Model Years.
Tank looks a little odd too almost like a miller slimline fuelcap.
Highly recommend the high power Connect van for drive-ability, not sure about bike carrying mind only did courier work in mine. The Peugeot Partner / Citroen Berlingo are ok little vans, beware the low power ones. We have the basic ones at work and they are very poor, not sure what engines (think a 1.4) we have but sometimes we'd be better setting a sail on the roof!
Against anything that leads to earth. On my Sherpa I earth them to the engine, however that is bare metal. If possible earth to bare metal to get the best contact (head steady, engine brace, mounting point).
If you don't seem to get a good spark you can get an inline spark indicator something like Spark indicator on ebay, this will flash when the sparks are sent to the plug.
When i changed the oil on an '06 290 I drained the forks completly pumping the cartridge dry. I then refilled the cartridge side with half the oil recommended and sealed the leg and pumped it, then i put in the rest of the oil and pumped it.
Oil types and levels for the 2006 trials models Paioli front forks
Oil level on right leg: 60mm With forks at bottom Quantity: 370 +/- 4cc
Oil level on left leg: 110mm With forks at bottom and without spring Quantity: 385+/- 4 cc
Oil type Idemitsu O J RACING TYPE 01 Viscosity at 40
Sherpa Model 80 Engine And Amal Concentric Mk 1
in Bultaco
Posted
My M91 Sherpa is the same. With the triangle box on the rear it was hard to start and was "fluffy" on throttle. Removed it, all is well.