pschrauber

+10 and use gasoline / petrol with as least ethanol as possible *, in any case to drain the gastank is the best way to prevent discoloring and bubbles. At the end of the season I use Aspen racing gas this have the benefit that it can be stored over the winter without desintegrate in something weird, (also this "stuff" should not be stored in the gas tank of the bike).

Most sealers work, the main point is to do the right preparation and here is the crux. The gastank was filled with oil-gas mix for years, but you need a completly oil free inner surface, otherwise the paint will not get a good connection with the fiberglas. I have therefor used small stones you take for tumbling to roughn the inner surface then some washing with acetone to really get rid of the oil. Last prep was to use the acid that came with my gas tank sealant kit. After this the known procedure. Gas-tank sealant was Kreem from Germany, there is a gas-tank sealant available that shares the same name but comes from the U.S. this is not so good, the German inventor and producer has given our a warning to use this product. Anyway if someone is interested, Caswell will certainly do the job as well: http://www.tanksiegel.de/ Here the warning about the false product, easy to find out as the text written on the sealant cans is in English and suppose to be in German, there should be an extra English manual on paper, ...: http://www.tanksiegel.de/usa-kreem/ I believe you better take Caswell as it is easier to get for you, the main task is anyway getting rid of the oil inside.

No I did not mention any production run or series but I like to be correct. The frame was modified with #4902426 and as 4706 units where made from the model 49 from 1968 to 1971 the bike of the TO (with #4902625 / #4902626) should be build between 1969-1970 which is just in the "middle" of the complete production run ... But maybe you can please tell the audience why Bultaco introduced this in 1969: And then I highly recommend for further information: - Francois Stauffacher: "Historia de la Sherpa T", (also in English available "Sherpa T the History"), - Francisco Herreros Alfaro: "Bultaco - La Pasión pour el Deporte", (also in English available: "Bultaco a Passion for Sport") Both namend autors do also state that the Kit was available in the end of the sixties / 1969 and btw. both variants where later available and do show up here and there (not often) for sale at least on the continent. There was later with the model 80 even a "Kit Excursiòn" with 10l gas tank and heavier flywheel for "motoalpinismo" (riding in the alpes) f.e. available. The benefits of the Kit Campéon were: 1,3kg lighter, narrorer and lower gas tank while having the same amount of fuel "on board" and a better weight distribution. I personal -as already stated- would leave the bike as it is, beside the foot pegs IF they show up somwhere for sale and of course the fenders.

I think so, the original was painted in two colors, this is irritating me, maybe your sidepanels where just painted wrong? Here a pic of the 250cc M49, early version: http://www.motosclasicas.org/bultaco/images/sherpa/sherpa_t_250_m49.jpg The contact data was already given for the UK, see postings above?

Hi Chris, back then when the older Bultacos did not have these swing arm protection rubbers feature we used a piece of a garden hose. We cut the tube lengthwise and fastened to it with a hose clamp on the swing arm. I used a yellow one looks nicly to the blue of the swing arm and works perfect.

Nice a photo, yours is an older M49 without the Kit, but I would not bother this is perfect. I would upgrade to the metal fenders and search for the right sidecover-airbox unit, keep it otherwise as it is.

The M49 was made between October 1968 to April 1971, the early models had a metal gas tank, an airbox with integrated side panels and grillcover for the mid exhaust. The M49 was a great success and in the end of 1969 the M49 was upgraded and these upgrades where available as a Kit for the older M49 models too, it included: - a combined single piece fuel tank seat with attached side panels, - a different, (smaller seat), - an extra airbox, - a different exhaust system. The later M49 models from 69/70 on were already fitted with these modifications from the factory.

To an M49? None ... keep it as it is beside the "Kit Campéon" if it isn't already mounted, the only mod I would do to this bike.

You can damage the outer edge of the aluminium tube with a screwdriver. To avoid this you can use a seal puller, (very professional), or the hook of a spring puller, (what I do / did), works too (but will destroy the rubber of the old bearing).

The sequence which bolt/nut to thighten first in steps is showed here: I thigtened them in steps with 3,0 Nm: - Bolt or nut # 01 to # 06: 15 Nm - Bolt or nut # 07 and # 08: 18 Nm

Hello I hads some problems getting the front axle off my SWM TL.NW. I just wanted to inspect the front brake as I want to ho to the alpes with the bike and when going downhill good brakes are a must. I could not get out the axle as the speedo drive did not move anywhere, all bolts and nuts where removed! It ended like this that I jacked up the bike really high and pulled the hole front end out (with the stanchions!). This worked very well and I could dismantle the front rear. But agian did not had any possibilitiy to remove the speedo drive, I discoverd (I could not measure that the axle has a notch! and the speedo sits in this notch, so the axle must be made out of two pieces? Anywany I tried to dismantle the axle too but had no luck here. Any Tipps in this case? PS.: BTW: the brake pads where OK, I just greased the actuator and cleand the hole unit and I was astonishd how they build the front brake setup, the unit is very light and the complete construction I would have expected mounted to a small moped but not a motorcycle ... PPS: I have mounted the complete front end again, wheel with stanchions at once, - what a crazy job -, I do hope someone has the answer here, I don't want to do this again ... .

If the wheel builder dismantle the old spokes and mounted the new ones OK, But if he got the hub and rim seperated and rebuilded the whell then, how should he knew the dimensions. (I once had the same problem with my KTM during rebuild, when I mounted the rear wheel the knobbies touched the swing arm which they should normally not do. By doing measurements I figured out the rims where not centred towards the swing arm, the rim had to move around 12mm off the center of the hub to get in the center of the swing arm and in line with the front wheel.)

When you respoke a wheel make sure you have the right distance between the outer edges of the hub to the rim. Often the hub doesn't sit centered in the swing arm or fork. The rear hub of the Bultaco f.e. sits towards the right side and the front hub towards the left side. To get the wheels, (rims), aligned the rim doesn't sit centered in the hub. I would not try to change the position of the rear hub with spacers as then you might get a problem with the chain which then might not be aligned, anymore, (front and rear sprocket should sit in alignment). As you have two Bultacos measure the distance between the hub and the rim of your other Bultaco Sherpa and then compare the measurements with the rear hub which has been respoked. Measurements:

The Renthal is surly one of the best for trials bike but if you really want something long lasting look through DID chaines. The DID 520NZ is a 520 size with reinforced brackets, tensile force is: 3650 kg. Surly not as light but will last very long.

If you use the standard spacer it should be OK. When the wheel was rebuild did the wheel got new spokes / rims or were the spokes deassembled and mounted again, because the hub rebuild swappt against one with steel liners ...? There is an offset between hub and rim which must be maintained when you respoke the wheel. (OFF TOPIC: As a reminder, thrust washer ... )

Yes stiction sums it up in one word. Well ... my English still needs some improvement I guess.

In my experience so far the Marzocchi fork of the beginning eighties have more "resistance" wherein compression especially for smaller bumps on the ground then the Betor fork. Not very much but noticeable in direct comparison. Maybe because of the slightly different inerta or whatever is the reason. I would describe it as a bigger stop-loss torque. (I compared the Marzocchi fork of my SWM (1980) with the fork of my Bultaco Betor). I do hope my misspelling of the word torque in my former post haven't lead to your question?

Just to note if there occur a "long distance" trade there is in my personal view a good procedure where the seller will get the money cash by collection and the buyer don't have to make a long distance trip twice or to another country. The buyer can instruct a shipping company to pick up the bike and pay the seller! Some shipping companys offer this trust service. This does cost the buyer some extra €€ / GBP but is often much more economically and expecially needs less paperwork at the custom border in my experience.

Another Issue might be air leaks between carb and engine, I would check the gasket between manifold and cylinder and the rubber connection nozzle between manifold and carb for - cracks in the rubber nozzle, - hose clips, do they sit thight? To check for air leaks before disassemble the side seals, ... you can demount the ignition cover, (be sure having neutral engaged), then start the engine let it idle then spray WD40 / brake cleaner to the places where you think that you might have an air leak, if the engine rev will change when you have an air leak as the engine will suck in the WD40/brake cleaner areosol then you then know where to look at, (only a little amount of areosol is needed!).

Yep the crank can get "out of alignment" this has to be checked before assembling the engine again. To check the alignment or any misalignment mount the crank in a lace or on two V prism on a surface plate, lathe is easier! Then place measure sensor near the flywheel of the crank. Turn the crank slowly a full turn and look if there is any "unroundness" it should not be more then 0.01 mm on the left side in drive direction or 0.030 on the right side in drive direction. If the crank is above the spec you need an overhaul, then you should too replace the conrod, the lower conrod pin an the lower conrod bearing if you havn't done this, keeps the crank assembly trouble free for the next couple of years.

If you still will go with a cable make sure to take one wihich as around twice the diameter of the standard cables you have for clutch or front brake. with a larger cable diameter and a larger more solid sleeve the "brake feeling" will not be so spongy. Orlando Calonder in Switzerland, (former Bultaco general importer for Europe (mainland), still in business), produces extra thick cables expecially for Bultaco.

I had seen some vids with Burgat when he was at the trials at mount Ventoux in France. There he rode his works bike from 1981. He might not be as cool when riding the worldcup back then, (I've seen him onth 1981 worldcup in Gefrees). But he is still an extremly good rider, So maybe there is an advantage of 5% or less when he is riding with that bike but do you really care? Not me it's nice to see him riding and he is still narrative happy. btw.: His works bike was and is modyfied too: - Betor forks, (when they still used Marzocchi, in Marzocchi forks), - cut rear loop, - different footrest position.

I use NoToil air filter oil, this stuff works very good and I can wash out the filter using any good soap and water, dish washing soap works nice. You just have to wait a night or day after cleaning until the foam has dryed out. (As cleaning the filter is the worst thing while maintain the air filter I started with this "feature") It is very easy to handle, pure some of the oil (very thin oil) on the filter put the filter in a plastic bag, (these plastic freeser bags works fine), then squeeze the foam until every part of it got covered with this oil. Take the foam out of the plastic bag when applied and let the solvent of the filter oil evaporate, takes half an hour leaving a very sticky covering. Then you can install the filter or put it back in the plastic bag for later use. I have always a spare filter which is oiled so replacing a filter when riding in dusty conditions is done quickly.

The bike is an import from Italy, the previous owner is btw. also a member of this forum. He collects trials bike and do have some more. Anyway I think too it wasn't used so much in trials events and trials training, maybe more for motoalpinisti, (hiking around up and down the mountains in the Alpes). But how knows as I found marks of one of the earlier hand painted register number witch started with TN = Tornio, then there is a decal from the town Moena left and last but not least the bike stood 30 km east of Bolzano when I bought it. The speedo shows 2970 km now I believe, so it did came around in northern Italy the last 30 years. In my experience so far the Betor forks have a little bit smoother action and less stop-loss torque.

Oh, yes Ross I forgot to post the outcome, thanks for the recollection. I did a research and ask for prices and set up's ... it ended with a pair of Falcons as I wanted a double spring set up likewise the Girlings had. I have mounted them three weeks ago, did one training with them, two weeks ago I had no time for riding due to family affairs, but last weekend I was on a classic trial and they worked fantastic. They were a little bit stiff in the beginning, but got quick smoother. I believe they just had to run in, now they respond very good also the setup of rebond and compression is perfect adjusted to my weight. The shocks are around 17mm longer then the standard ones which increases ground clearance and also improves steering, (the chain is still not touching the rubber at the swing arm axle). So I'am very pleased and have to thank the members of the forum here for the good advice. Next "project" is the fork which needs an overhaul too, (the seals are a little bit worn ... and I would like to improve breakaway torque, switch to a Betor fork.