I still would prefere just standard plugs, the expensive ones doesn't work better for two strokes in my personal experience, the super expensive plugs for racing are out of financel reach and the other high tech plugs are made through the demand of the car industry because the sdervice intervalls has been doubeld at least. Thus plugs with longer durability where needed which doesn't mean they work better!
If you don't have a bright blue spark whioch do even makes a noticeable noise on a standard Bultaco magnet and point's ignition you have an ignition issue.
If there is a blue spark than as Nigel Dabster already mentioned the carb or his surroundings are the problem,
I personal doubt it's so much better as in electric conduction copper is only outperformed by silver even gold is less good!
Physics measured in: σ in S/m
Silver 61 · 10^6
Copper 58 · 10^6
Gold 45 · 10^6
Aluminium 37 · 10^6
Wolfram 19 · 10^6
Probably the tip of the standard copper plug is a little bit a backdraw but the connection between the cooper core and the tip is made so that as much as possible electrons can be transferred...
Had similar effects with Standard plugs NGK BP 5ES on Bultaco and SWM, it was bad, they even spoild the plugs total until no spark occured, which too happend in these moments you never wan't it would happen.
Try a hotter plug, my bikes are running much better on a BP 4ES!
It must be someone who knows all about Bultaco the bikes and all tweaks, repairs and builds, have all the connections knows where to replicate parts and of course he or she has to be good in business too.
I don't think it will happen by someone new it will more likely be bought up from someone how has a likewise business like probably Iván Cireé, (that's a guess !!!).
Would be great if Orlando Calonder would buy them he would be perfect, I believe he has the financel power too. But he is also of the old generation.
There are cables around where the wire is OK but the cable hose which is basically a metal spiral with a plastic coating at the outside.
When you engage the lever most of it's energy is used by pressing the metal spiral together instead of engaging the brake.
My personal favorite for cable are:
- Swiss Hortz cables or
- Venhill cables with thick wire.
I never had problems with NOS brake shoes and also in my experience they work best just a tiny bit better then anything you get made from today probably because they have still as best inside? (I use a mask when working to my brakes as the dust ... can be very unhealthy).
That was only applied -as I know- to thw TXR model which at that extra plumbing to crankcase, carburator and air bos with an extra Little tank inbetween.
But the clutch casing would ne different.
Is there a screw in the power front of the engine case?
If so than it might be a self made solution (I guess).
I just has to use the drain screw once when I was first time in the Alpes coming from 50m above sea level and tried to start the bike in 1500m. My low level carb adjustment overflooded the crank really fast ...
Yes these are the pictures I sent noel spread a link to my picture stack as I can't perform so well just with a smart phone equipped.
All internal were taken out instead a conus shaped hole tube with insulation was installed.
Weight loss is about a third I don't have the number at my hand now.
No difference in performance and loudness beside a slightly better pick up of revs. The hole unite is thinner then the bulkier original but looks very much the same.
I' ve sent you the link to my picture stack where you can take a look, with a smart phone my performing depending the www are sadly very limited, you might lol there.
I use Aspen too, to prevent detonation in high altitudes I use the racing mix (99-102), but too the standard mix for the saw and brush cutter.
When I recently needed some fuel for the saw and the brush cutter for some meadow and forest work and went to my local shop they had Husqvarna mix for sale the same indigents, so based on alkyd like Aspen.
It should have a bit more octane (98) than standard Aspen (95) and is much price worthier instead 18€ per 5l just 13€ per 5l. I tried it out with the brush cutter and after 2 refills I'am very pleased smoke free engine is accelerating great stable high rpm no spotting of oil when using low to mid rpm. The fuel is colored and it seems it's really blended with Husqvarnas 2stroke oil as it has the same nice smell. Anyway will try it out to the bikes now when I come home.
I'am in summer modus at this moment here in the archipelago around 20km from the coast the www is accessable but not very fast when I will be in the beginning next week again at the nearest vilage (supermarket). I can sent pics again if that is OK.
And I will clean up my PM messenger inbox inbetween.
As most fork springs get tired with the time you often look after a pair that's still fresh and fits to your machine and personal weight.
With the fork lit you get new springs that's suits your weight, with the cartridges you get a much finer reaction and too a more progressive dampning.
The rebuild makes sense if your stanchions are straight and chrome is good. ( I never got an old bike so far where the stanchions where really straight.
Yep have them installed works nice. The unit with air cartridges on both side works best. The other set-up with cartridge (bought to the TR) has in one side the cartridge and in the other side adjustable springs this set up has more tweaks but makes sounds ... kind of "clong" while the fork get's suppressed.
I don't like the noise and for adjusting you have to take out the springs ... so if again I will go for both sides with cartridges again ...
As you mentioned that the bike dies at less run better when the choke is on, have you looked around the rubber inlet between carb and manifold is there no airleak cause of cracks in the rubber not only in the body of the rubber flange around but too to at the sides from the inside to outside. Sometimes the paper seal between cylinder and intake can have been damaged too this connection is thight too?
Last not least just try another plug especially IF there is a plug with inbuilt resistor mounted. In my personal experience the bike runs better with a hotter plug then recommended. For NGK it should be PB 5 ES but that type does fail without warning, now using a PB 4 ES which does the work now for two years, (may be I'am a tad slow too).
I just rode the National in Colorado in the Vintage Twinshock class on a 1976 Cota 348. The old Michilen was splitting cross wise on the knobs about 1/3 of the tire. So about 12 really bad cracks. I cleaned 28 of 36 sections. New tires are over rated.
= super skills and a twinshock Bou? Sorry for winding up but it was so obvious.
It really depends to the underground and yes in classic trials it doesn't matters so much, the radial tires came first in the beginning 80's and were firstly only available for works riders. With the TY mono the new Michelin radial tire was available for the public in W and S version, these tires changed the riding style completly in trials.
W = winter = temp. under 17°C
S = summer = temp. over 17°C
Anyway the benefits between a very good or a decent trials tire when new are also obvious on a twin shock bike the way the carcasse is build (diagonal or radial inforcement makes a huge difference) and what rubber mixture is used really makes a difference.
Still 75% is up to the rider and with a tire that sticks more to ground even on slippery and wet surfaces gives you more confidence.
I haven't tried out to ride with too little air pressure in doubt I use a tad more a puncture is something I really don't need as I' am very bad in working with tires take them off and on again...
Nevertheless I believe it is possible to ride which less air in a tubeless tire then in a tube tire. There is less risk the rip of the valve. But there is to both type of tires the rust the tire will leave the rim bead more then it's harmless.
Depens to so many factors where you have ridden, have you done some road riding with the bike, age.
I recently changed the tires for the SWM they where mounted in 2012. The edges were pretty well rounded and there were too some deep cuts too. Then the knobbies of the tire had some wear in highness too due to some road riding. But mostly the tire got stiffer compared to a new one I had mounted to another bike and in fact the newer tire did stick better on nearly every ground. Interesting on grass there was no difference as you mentioned. But sand, stones and logs were significant better to travel with the new tires. To mount them "in other direction" I did not test as the in rear stiffnes was my personal reason to change.
but the appearance ... well ... there is room for improvement 
Stumped By My Sherpa.
in Bultaco
Posted
I still would prefere just standard plugs, the expensive ones doesn't work better for two strokes in my personal experience, the super expensive plugs for racing are out of financel reach and the other high tech plugs are made through the demand of the car industry because the sdervice intervalls has been doubeld at least. Thus plugs with longer durability where needed which doesn't mean they work better!
If you don't have a bright blue spark whioch do even makes a noticeable noise on a standard Bultaco magnet and point's ignition you have an ignition issue.
If there is a blue spark than as Nigel Dabster already mentioned the carb or his surroundings are the problem,