pschrauber

May be for those that haven't seen the inside interesting, here an opened rear silencer, with the hole tube in the first section and the chambers and tubes inside the rear section. The first section works as an standard absorber, the rear section after the Helmholtz principles: Her one of many possibilities, in comparison (top original, below modified): From the rear: The Helmholtz section works nice each chamber or hollow is different so when the fumes go through parts of the noise spectrum will be filtered away or weaken, any way due to the small openings the system provides a constant back pressure. Which limits the "free breathing" of the motor, it would a likewise effect to close partial the openings to the air box. BUT as the standard 2stroke engine has flushing losses (beside the exhaust fumes also fresh gases exit), most 2strokes need and have a return flow function, provides through a pipe that has a cone tube that opens slowly and then is closing in diameter again. The original shaped mid section of the Bultaco doesn't have any cone form beside the end of it were a small hollow is, see picture: So with none additional "back pressure" you might get a worse performance, the solution in the picture above show a bigger hole oval shaped hole tube that has a slightly s-shaped curve inside which is in own experience a good compromise between a straight tube with no back pressure and the original one, too isn't visible at once narrower then the original and quite lighter. (a suggestion of many possible ...).

The noise reduction system of the rear silencer is based on the Helmholtz principles using different volumes' and different sizes of tubes. As it is constructed now it works for all noise levels that comes from the engine. You can leave the system too as it is as build up crud can't effect it much. Anyway the rear silencer build up a permanent resistance of "air pressure" against the complete exhaust system that is mounted before the "chambers" and tubes. Thus providing less noise but too restricts the performance here the build up of motor revs., one of other reasons the bikes with this era and silencer react/respond so slow to throttle. If you want that the bike react faster but deliver as less noise take out all baffles and tubes and place a hole tube instead through the complete silencer. The diameter around 25mm. Then fill the hollow between the hole tube and the rear silencer well with insulation, the modern stuff works best mineral insulation less good. But the insulation will soak up oil residue and after a time your bike will sound louder and you have to replace the insulation (the backdraw) but the engine will respond better (the benefit). Now it's up to you?

OK here you are, again from the manual, as it's so nice pictured there:

That's easy here the pages of the manual for the TR34: For timing I suggest to use 1,6mm before TDC as stated in the manual, 1,8mm makes starting more difficult especially when the engines is cold, (at least in my experience the motor doesn't like to start when it's colder outside, probably the Italian genes? but once warmed up starts then easily, For easy cold start I lean myself standing in the footrest on the bike against a tree ... then a good firm kick were you can put your body weight in. Then mostly nothing happens after first while the second kick then awakes the engine). I too use for trials riding a colder plug (manual states Champion N3C which is between NGK B7ES to NGK B8ES) which makes starting also easier, the B7ES plug looks too much better and doesn't foul as easy then the B8ES, but it's probably just my riding style, if your plug looks really good you should stay with the plug you haven choosen.

Pretty perfect replies to your questions I can't give any better hints. Just one in own experience: Try first to get the bike running proper, when the bike is running well and all mechanical issues are done and you still want to do "cosmetics" it's much more easier to do it then. Hopefully the bike will already look good when it's functionality back. I have done two restaurations that ended in a shiny bling outcome. But personal will not do this further more as it's a pitty to ride them in the dirt. The follower restauration I have done were "just" to the technical and functionalities of the bike also solving originality issues from former owners. And I like the outcome much more as there is still the original paint and fenders the paint may be discolored the plastics may be faded but they do look gorgeous this way and maintained. Best thing is you like to ride them too and I believe too as everybody is doing resto mods too these real original runners will be more worth in the future.

I have forgotten ... our license includes an insurance for the rider and the bike: - partly disability benefits: 32K Euro - full disability benefits: 64KEuro - death: 16KEuro - medical expenses: 10KEuro - medical repatriation: 4KEuro - rescue costs: 3KEuro - repatriation death: 2,5KEuro - technical help: 1,5KEuro - Immediate solutions with serious injury: 1KEuro Very low... for substance help for 50KEuro add another 131 Euro, for 110KEuro add another 242 Euro.

I can confirm that numbers an EU Historic trials licence in D is 200€ a year, for international modern 319€ a year, at least approved by the FIM and written in three languages ... for any rider over 50 years you have to ad the costs of a medical fitness test with ECG and all the trimmings thus you have to add another 100 - 200€!

7075 aluminium or T6. Sometimes relatively priceworthy in combination with mashed plates (tears mash) which you get in small sizes.

Moving the axle of the swing arm as much as possible towards the front sprockets will - as already stated - reduce load sequencing reaction a lot.The distance between the front sprocket and the swing arm of a Sherpa is quite impressing so I think that effect (which hardens the the rear suspension will be much less noticable). In my experience bikes with "short" swing arms do too have the tendency to have a more nervous rear when rolling over "bumpy" obstacles like a field of bigger stones for example. That's one of the reason why the Majesty TY had got an about 30mm lengthened swing arm. Looking forward to any pic's in this matter.

Yes that makes sense. The numbers are equal and Somalia and Sudan, ... well there might be some translation issues too the communication wasn' t as good then. It can be that the used military bikes which had seen service for at least four years got an "refurbish" before they were sent abroad. This procedure is at least very common in Germany when used military stuff from the Bundeswehr is sold to foreign country's by the government it get overhauled by the factory were they were build. As CEMOTO was already paid through the government why shouldn't they hit two birds with one stone and let them overhaul the bikes from them before they were sent to Somalia. That's quite a huge study project thesis! OFF TOPIC MODE ON Anyway cool incident I was too at the Military Police (Feldjäger) in the Army during my service time and had too ridden bikes sometimes in my army service time, mostly we used cars. We had Hercules offroad bikes and BMW street bikes. The Hercules was a little bit to much underpowered and I managed to break the frame off one when riding in the woods. My service stations were spread over Germany Celle 3 month, Sonthofen (Alpes) 6 month then Bremen, in between Wilhelmshaven and Bremerhaven (in service for the US Navy). OFF TOPIC MODE OFF

Not really you can read the sentence as 100 Metrallas for Spain and additional 200 Metrallas for Sudan, but too 100 Metrallas for Spain and 200 bikes of a different model (not named) to Sudan??? I'am still a bit astonished about the Sherpa's sent to Tahiti and Guatemala.

Didn't knew that Montesa were too machined in Scotland. But found two additional articel about Bultaco. One article showing the cringled exhasut manifold on a Bultaco Sherpa and stating that there are 280 workes but just 100 are really working and the wish there might come new models. Additional an articel about the Italian Montesa model 242 that got a separate gas tank which is lighter and more resistant, both published 1984 in July Issue 100. May be a hint for research of the last Bultaco Sherpas a longer articel about the recent past and futur to Bultaco and the other two Spanish brands, published in December 1984. In short: The introduction refers to a law in Spain set up by Franco that workers in a factory from a given size can't be dismissed and that the former social democratic goverment don' t wanted to change this law for political reasons. The previous owner and his family had partly under pressure from the workers partly voluntarily left the factory. That Cemoto is still existing is due to the tremdous suppoert of some employees and foreign importers. The production numbers are to low to employ 280 workers, thus there are only working around 50% of the workers while the rest were paid by the goverment. ... The monthly output were recently (1984) around 100 bikes per month, which equals to 30 to 40 workers, with 140 workers the output shuold be 500 to 600 bikes. At the Moment (Dezember 1984) work is done by orders. The following orders are: 100 bikes model Sherpa T250 and T350 of which 80 bikes are for UK, France, Venezuela, Tahiti, Guatemala and Japan. 100 bikes model Metrallas for the Spanish army, 200 bikes model .... for Sudan. More long-term contracts are missing. On average 50% of the motorcycles were built for export. For better sales the bikes have to be revised thus Bultaco want to concentrate on the most successful model, the Sherpa T. Changes to the Sherpa T: - new color, - altered and improved gastank seat design, - improved engine protection plate, - primary kickstarter, - progressive clutch action, - shorter and revised wheelbase, A competitive support with own riders, weill not happen due to the cost. There are high hopes in the new MK 15 engine, this engine shall be used mainly in the Pursang and Frontera models.

To the article as previous mentioned. The improvements done in UK were too sent to Barcelona so that these could be integrated in the production but it did not happen. Also back in summer 1984 were the rumors that there will be an upgraded trials model in the end of 1984 available. But it did sadly not happen. I have to look up in the old issues when the end of bike production was announced.

I did a quick look about improvements and news about Bultaco back in the days, but there were very few. It was noted in Trialsport issue 101 from August 1984 that there were made improvements to the Sherpa as for example the longer swing arm with a more forward moved swing axle and that the modification was made by Reg May on behalf of Comerforts and that these improvements were sent to the factory and ones hopes that there will be the development of a new model at the end of 1984. Here a clipping with the short article: It did sadly not happen

Well, probably ask Orlando Calonder in Switzerland, may be he knows, he was in business as Bultaco Importer then and is still as manufactor of cables and spokes and dealer for Bultaco parts. He does not like to talk about the time after the bancrupty, I have already asked ....

To the bike production at Derbi I have read in several magazines and books. Too in an article about the future of Bultaco from 1982 on German Trialsport Magazine. It makes too sense to set up the production somewhere else to get the old equipment ... sold. The model 199b is the only Sherpa with no parts catalog I believe this is an evidence that in the end not everything went always in the right direction.

To the numbers, as mentioned before, when Bultaco made up there system of frame numbers they should have had a system that is in itself logical. With new models they changed the first three numbers and started again with zero. With the model 199a and model 199b these were just models with "small" improvements, so they went counting up between model 199 up to 199b I think. I don't think that there were given double numbers in purpose, at least all vehicle data in Germany were already in the end of 70's recorded electronically and the data collected at the KBA (Kraftfahrbundesamt), once they were put in traffic, (not before). Same with the Italians which did punch the registration numbers below / under the frame number to the frame of the bike when imported as a single bike. Motorcycles with double numbers could be easily noticed later when set up for road and this done by the manufactor would be a crime. I believe when the reminding workers of Bultaco that didn't got a job after the bankrupty of Bultaco and were assembling bikes from piles of spares without superstition at the Derbi facilities as part of a social program of the state, may not have been precisely those that were easy to convey, thus couldn't count right ... hard thesis ... I know ...

In my personal opinion the frame engines are quite correct they begun with the 199 model: 199 : first number: 199.00.001 bikes made: 5.960 so last number: 199.05.960 199A: first number: 199.05.961-A bikes made: 6.915 so last number: 199.12.875-A 199B: first number: 199.12.876-B bikes made: 1.778 so last number: 199.14.653-B I looked up the other frame numbers of other custom and road register documentations I have: First document which sounds OK Bultaco No.: 199.13.314-B, Imported to Germany: 12.10.1981, through custom of Bad Reichenhall, first road registering in Germany: 21.01.1982. Second document is astonishing: Bultaco No.: 199.14.688-B, Imported to Germany: 30.06.1983, (through Switzerland (bike was former registered in CH)), through custom of Freiburg, first road registering in Germany: 30.06.1983. very interesting this number is 35 digits above 199.14.635 ... So another incident that there is a number mismatch ... start to get interesting ... but this theme hold me too long awake ... bed time ...

No my bike is with 19913348 is much to early. Why do You want to know the last number, the production number was stated by Francisco Herreros in his Bultaco book, the number was 17xx bikes when I remember right (forgot the last numbers) ... surly he might be wrong. The research might be difficult as due to the registration documents (I have some of different model 199b bikes) were all 199b models imported individually to Germany and Italy and thus got a separate customs treatment.

Two liters cost 32€ the same amount of standard coolant for motorcycles 14€, that's twice as much. But it doesn't matter because you can use it nearly for ever or at least as long as you have the bike. When Jay Leno filled that decades ago in his racing Bugatti from the 30's and haven't changed it yet (and a racing Bugatti is really much money) so what should happen. Oh and there didn't happen anything to my bike either.

I' am Bohemian so I can tell the real story but the photos do tell the issue ... water isn't the best for coolant of magnesium and aluminum cases. Something I have already seen in the past. For a trouble free futur of riding my hint not to use water based coolant. This time even with a link of a product I use: http://www.evanscoolants.co.uk/ It's a British product too so it should be a non brainer for you. In my personal experience ... it does work, (KTM 500 2stroke 1989).

I now only use water and thus corrosion and debris free coolant, too many issues with internal corrosion and gunked debris in radiators, caps and water pump houses in old bikes got me to this decision. You might me call Bohemian but do I care about the costs no. It might be twice expensive but the small amount you need and a debris and corrosion free future is nice.

The coating inside the con-rod is mostly hardchrome, there are manufactors that will recoat the con rod and pin if in need but it's a one off custom hardchrome ... I personal had made very good experiences with Wissing Hardchrome in Germany, they do all kind of hardchrome, mostly to big machine equipment and gears weightening several tons but too motorcycle stanchions (hint hint). They would rechrome the surfaces, grind and polish them to your spec's but I believe it will be at least as costly as a new one. The web page of Wissing, (the pictures of what they hardchrome are quite interesting ...): http://www.wissinghartchrom.de/bilder-galerie.html

On some bikes with similar rims the inner tube rotate by some not I have no clue why and why not. Apperently my strongest bikes SWM and Bultaco don't have the trouble with valves in angle. Instead the little Panda with red Acront front and rear similar to the Bultaco and SWM has a valve problem on each wheel. Easiest way to get rid of it is loosing the bolt of the tire holder take out a little bit more air then: for the front wheel: roll backward and the pull the brake, should work nice. for the rear wheel: depending to the angle just roll then engage foot brake. This procedure is 100 times easier an taking out the wheel, take out air squeeze the tire edges to the middle, ... and it had worked for me astonishingly well.

There is the saying: A gentleman should have some bikes, (can't have enough if you are obsessed in this matter). Anyway as older the bike as more different is the ride. A monoshock is quite nice but today can't be ridden in every classic event. With a true twinshock you have a broder choice. As older the bike as less it matters which one you choose, it's really up to you. The bike should fit your personal requirement's and taste