carl ekblom

Yes, usually a few meters backwards is sufficient to get the valve in correct position

Yes, tubes are wandering inside the tyre. Tightening the rim locks doesn´t help This is a trick I learnt from a Speedway guy. Empty the tube. Push the bike backwards until valve position is correct. Fill the tube with air. This has to be repeated every 2nd occasion or so. Tubliss fix this problem as you don´t use a traditional tube. I would say "a permanent fix" at the expense of slightly more difficult fitting. Tubliss make it possibe to run tubeless tyres at tubed rims

As far as I know the duplex chain also use another tensioner, clutch basket and engine sprocket. Also think the ratio might be slightly different, but I have read (somewhere) that trials people do the conversation. Original Joresa single chain is special dimension

I have an All Balls Fork Seal kit 35x47 (KTM SX65) for one of my Bultacos. Long life but very high friction. Will not buy them again. Perhaps some other parts are good. Found them at a local shop

Yes, I remember 0135. The 01235 came mid 70´s. One of the first factory built trials bikes was, as far as I know, Royal Enfield Bullet and it came in 1949. Well, there was one in 30`s but it was not a trials bike Think the reliability trials was partly observed early 1900´s but don´t know for sure when it went to 100% observed. Think the name ISDT (international six days trial) has to do with reliability trials. From 1981 called ISDE (international six days enduro) Thanks everyone for giving me some background👍

Someone know when observed trials started. I guess shortly after WW2. I believe trials in a form of reliability test started early in the 19 hundreds, but observed trials in a form we would recognize as trials today🤔when did this happen🧐

But I must say, in more then 10 years I never had any problem with the magnet. Thought it would be but not so far. Only with the strap. Keep one spare magnet somewhere at the bike in case it disappear . No problem at a steel framed Bultaco.

May, I suggest you use a Lanyard Switch. I think it´s an essential safety device. Be aware that Apico and Jitsie have reverse polarity of the magnets. So you can not exchange without problem

Good question👍

If Mikuni, might have flooded. Check Spark Plug, If wet might have flooded. Edit: This happened often to me before i learnt what to do

I guess any paper capacitor meant for ignition would do their job, but a paper capacitor would withstand far more voltage then 6V (at least 400V or so). It must be in parallel with the breakers but not necessarily at the breaker plate (as B40rt says), can be placed somewhere under the tank. This was a common fix, during its days accordingly to Yrjö Vesterinen, when they had to change capacitors quickly. For breakers try to find NOS as they are correct for the engine. I have got the information that new Bultaco breakers might be meant for Lambretta and they screw up the Abriss distance. Yes, I know as I think this happened to me.

Yes, as far as I know you can. Haven´t seen those at Concentric Mk1, but at Mk2. Might function as a small restriction at full throttle but I am unsure. If they do you may test a slightly smaller main jet, or they may increase fuel flow at full throttle. I would thoroughly clean everything and keep it as it was to avoid uncertainties. Be aware, the Amals function well but have a very limited lifespan. This is why we now have the Concentric Premier carb, with anodized throttle valves an some added extras. A few of them even have alloy bodies

Lets see🤔......BS (sinistra?) is a left hand carb, BD (destra?) is a right hand carb. Generally, if idle mixture screw is at carb outlet, it´s a fuel screw. Is it at carb inlet, it´s an air screw AS is a left hand carb with screw connector These guys have a lot of carbs and parts https://www.dellorto.co.uk/ Here also https://www.splatshop.co.uk/

Amal´s often have a worn throttle valve/ carb body. This shows up by problems getting a stable idling. Don´t fall into the trap of putting jets and nozzles that looks to be correct, but they may not be. I only put jets, nozzles and needles from parts in original wrappings sold by a reputable dealer, and correct sizes accordingly to original manuals or accordingly to Amalcarb.co.uk. During the years I have seen a number of incorrect combinations that don´t work well, and people have a tendency to blame Amal for everything inc bad weather.☹️

If you are planning to keep the bike......Buy a reputable electronic ignition and get rid of all sorts of strange problems. Well worth the money. I am at my 4th year with Electrex now. Only had one loose connection last year. Easy to fix. Instant starting, good running. Before, with breakers, was always problems. Most often, suddenly, didn´t start. Albeit when running it was quite good. In the end I get angry 😒and bought a new ignition. Few days later.......no problem at all

PHBL 20-26mm PHBH 26-30mm Think the PHBH came before the PHBL but don´t know when they appeared🤔

It´s quite a bit slower with 10/48 then 11/46. You can roughly estimate 1 teeth smaller on front sprocket equals 4 teeth larger at rear sprocket. Try and see if you like it. Use 2nd gear if you need speed. Will also be slower on 2nd gear and all other gears. Perhaps 2nd gear will be more usable

Gearbox oil should have no contact with engine. Thick gearbox oil may possibly affect gearchange and clutch action (if the same oil). Unless oil leak would not have anything to do with engine.

Yes, gearbox oil in engine smoke and smell. Best you can do, is as soon as possible, completely drain the tank and replace with fresh petrol and correct two stroke oil. However, it may need a period or a few tanks to get rid of all gearbox oil. Also check spark plug for carbon build up. If done promptly and properly, I don´t think your engine has taken any damage. When I was young, I ran hours with gearbox oil in petrol without noticing any permanent damage.

35x47x6-10mm seals are standard and can be found in many options. If they are thinner, don´t worry. It is easy to put a 35x47x7 seal in a space for 35x47x10. If you like, you can machine a spacer, but in many cases this is unnecessary. Be carefull not to scratch or damage the seals when assembling the forks. Grease/oil and some tape might be your best friend. Use a scraper ring above the seal.

I would say ordinary NBR seals are fully adequate. Use original seals and bearings. Take seal out then heat the halves with hot air gun or similar (gasol?). Check temperature with an IR thermometer. I guess 100C is good. Later when putting the crankshaft back you may heat the bearing(s) to max 150C (no more). Check with IR termometer(IR thermometer is important). IR thermometers are not expensive nowadays.

I don´t clearly see, but is it a modifed Norton Roadholder?

You may try without one shaft each time, to find out where problem is located.

I guess your gearbox is OK. I think it´s the selector mechanism. To examine it, as far as I can remember, you´ll have to remove the clutch basket.

It looks the Finnish flag blue is Pantone 294C which seems to be little more blue then RAL 5015 so correct shade of blue looks to be 294C for 199B and RAL 5015 for 199A