pschrauber

Yes yes in doubt keep reading Thomas F. Yezerski, see here: Click for Booktitle

Mmmh then there is something different the issue. The engine sounds as it don't want to accelerate right and when it finally archieved some rev and you close throttle the motor want's to run away but doesn't have the power ... so finally decides to slow down. - Timing of the ignition? - How does the plug color picture look like?

Does run but not very nice still a bit lean and still not crisp. The engine does rev a bit longer after a throttle burst then it should. I believe the carb is worn out typical slide, needle and jet. The engine can also run much slower in idle mode, Sherpas love to rev slow when ideling I strongly think there is still another issue

I don't like to hassle around with heated parts and get burned by them, I recently got burned a lot while trying to replace roller bearings to a swing arm... So now using ice spray to cool down the bearings and gentle heat with an hot air gun. This combination works very well: - first heat up the parts where the bearings belong, - then a spray to the bearings to cool them down, - and finally let them drop in et celá.

Yep I can confirm that to every drop of HTX oil. This stuff - albeit expensive - works fantastic in every twinshock bike I have used in different makes build from 1979 to 1984.

ATF or Elf HTX 740. ATF is cheaper works btw. much better then SAE 30 and too then SAE 140 in the gear box.

Does it feel compression wise like before? You might loan a endoscope there are quite good once with USB hub available these can be plugged to your notebook and do deliver quite good insights. Somikon makse an USB hub endoscope that has a 7m long wire with HD view for under 50€.

Sorry but as the compression apparently hasn't come back, at least you haven't told so. The chance the engine isn't toast is not high instead the opposite. We might see or read about it ... Surly I wish you luck and will press thumps (if that can help). Looking forward to pic's in the next couple of days.

I think the engine has suffered some damage it would be super interesting to know what. I believe you have blown the rings and with them everything else touched by them. The bike got too hot to little oil which caused much wear hot blow by and you will need a new top job now. Yes a bad prediction I would be glad if not.

The Bing carburettor has a piston made out a softer material as the carb body to prevent wear to the cylinder. The piston therefore has to be replaced regularly. That is a good idea much better then other carburettor's of that era where piston and carb body where made out of the same material. The PHBH Dell'Orto has too a softer piston then carb body. The Mikuni VM at least also. Anyway in my experience the Bing works asthonishing well when set up right and maintained. The Dell'Orto is a bit complicated to adjust because of it's bazillion possibilities for adjusting if you have already 5 different slides to choose it's a challenge. Bing's offer not so many possibilities but need spot on adjusting too. Mikuni's or OKO carbs you can screw on and they work it doesn't matter how the carb is adjusted the engine starts and runs mostly OK. The main adjustment for OKO and Mikuni is which diameter you use. You can slightly improve the engine by fine asjusting in the carb. I have a 125cc rebuild to 200cc Yamaha and the original carb worked on the 125, is btw. with same diameter and slightly different jets also standard to the 175 and do the job even on the 200cc motor. So very forgiving carb model which pleases you fast.

That is quite an early bike one of the first 200! May the force with you that's a BIG project!

Here the colors they match RAL pretty well: - Frame red is RAL 3020 Verkehrsrot, - Tank blue is RAL 5013 Kobaltblau, (not Stahlblau, that color code has too little red). See here: The right picture shows gas tank and seat which is blue too.

The gas will not burn slower or even faster if you have more octan it will just ignites later.., with higher octane fuel you will have less chance of detonations'. As more compress ratio the engine has as higher has to be the octane number. If you use 100 octane but you could too use 95 octane nothing will happen the bike will run as usual. As a benefit you will never have any detonations. As more you cone near by the recommended octane rate as a minimum as more is the chance getting detonations under load. gasoline with lower octane will have the tendency to be ignored prior to the spark plug, will cause heavy detonation and can damage the engine quite easy. Mostly race gas or gas with high octane is of very good quality and has less indegrents that are just mixed to the regular pump gas by law or economic benefit as bio alcohol certain stabilizer and so one, thus race gas is often a bit better in power output. In my personal experience I like Aspen gas very much invented for forest machinery and based on Alcylate instead on oil. It burns without soot and without smell can be stored for years comes with 95, 98 or 101 octane but it is expensive. For a clean exhaust and engine, your health and the environment a real good fuel.

Nice job and yes the aluminium parts should be as bright blue as shown in the picture. Just the snails they have not been coloured instead left natural in aluminium grey. The parts on my bike are too purple by sun radiation...

I had once written up the color code in RAL but can't find the notice. I can look up the color code again no problem if not someone else has the numbers at hand.

That's a nice bike model and I have a similar bike, I have done a restoration on one TR34 too but left all parts if possible original, no new paint job, still tons of things done: - rechromed and aligned stanchions, - new clutch, new kick-start mechanism, new primary drive, (the complete set-up), - new conrod, piston, cylinder plating, - new rear silencer and overhauled pipe which had to get a paint job* - new reeds, carb completely overhauled, airfilter, new rubber air-box to carb and carb to intake, - new cables and brake hoses, overhauled calipers and actuators front and rear, new brake discs, - ignition overhauled, (new electronic parts), as it is prune to fail, - new chain and sprockets, - new tires, wheel bearings and seals, * I choosed grey as a paint for the exhaust as it was formerly just clear coated, as pulling out /repair the dents and finishing the pipe left some traces.

Wow not only to the tools but especially to the new crank room and cylinder basement. What an effort I know of only one engine where this was made too to fit a bigger cylinder and crank to a smaller engine block and that was a small serial production of about 50 engines. I too like the engine stand made out of wood beams. Something I do too for various occasions like wheels, rear shocks, swing arm and so one as they are so easy and cheap to make from left over carpenter jobs and afterwards you can burn them up in the oven producing heat

Brakes and yokes (triple clamps) are from the 242 model, the 242 and their successor where further developed, model 304, 307, 309 and 310 ending with the 311. After the model 350 there came the Cota 330 and the the last Cota 335 which ws the last big cc bike, the 242 and later 304 where simply easier to ride in comparison.

A mineral deficiency is usually the cause of convulsions/cramps. It's often an electrolyte disorder, with a deficiency of magnesium. Give magnesium pills a try, these are priceworthey and not dangerous. The effect not getting cramps should occur after a couple of days, if so magnesium deficiency was the case. Hole grain products, bananas and cheese have much magnesium inside as a tip.

The bike did run fairly good with the Amal carb, but was slow in response, it felt supersmooth but was a bit liveless for my personal taste. As the Amal had worn itself down (both slide and body), one screw was sheared off, the zinc die cast is an issue for itself ... So I looked up the PHBH as it's contemporary. The bike changed it's attitude being now much more lively and revs up quicker, it also have now an ultra low idle. However the engine does hold the revs a bit long after closing the throttle in my opinion. In all it's an advantage for me, if it would be for you can be questionable.

The air screw sits at the rear towards the direction of the air filter and regulates how much air will go to the idle nozzle, the result is a qualitative setting, The fuel mixing located towards the intake of the engine regulates the amount of gas leaving the idle nozzle (already premixed with the air) which is a quantitative setting. You have more possibilities when using the air screw but too a bit more harder work to determine what's right

Testing days are over now. I had some testing involved and finally got an good result, I checked first in the garage, than as usual decided to go with something different but at the field test out side I had to change again and again until being pleased. Montesa 242 now mounted with a Dell'Orto PHBH CS carb, (Yes with air screw as it's advanced in technology compared to the fuel screw type*). I also exchanged the tiny original exhaust tube at the end for the aluminum WES type which reduces loudness a lot is as heavy or light because twice as big. The result: carb: PHBH type: CS slide: 45 needle: X4 / X44 position: 3nd choke: 60 idle jet: 60 winter, below 10°, (58 summer) main jet: 95 winter, below 10°, (92 summer) needle jet: 266 fuel valve: 200 * There is some rumor that air screw Dell'Orto's are a pain, that's not true, they simply are a bit more difficult to adjust but can provide a better performance.To the air screw, it's just the opposite in adjustment, turning in means richer and turning out leaner. The air effect takes time to affect the carb, for proper adjustment, use a slightly higher idle rpm, then really slowly turn the screw and begin with half a turn out until you reached the point where you have most rpm, then the air screw is adjusted. Anything below 1 turn and above 3 turns means you have to use another idle jet or nozzle. Still a tiny bit too lean ...

That are sad news, very sad news. I had some conversation with Larry during the years not much but some, it started by a personal message why I haven't been at this forum for a longer time also about my Sherpa. He was a nice guy, I will miss his input and the talk about Bultacos and so on. I really appreciated that he truely cared. Thank you about the information: "Death is the surest calculation that can be made."

They where simply connected to each other and in the middle the tube was cut open.

Sadly the bolt pattern to the TXR is super unique, also the pattern for the front disc mount is one of a kind. Then the engine uses internal a different gearing compared to all other previous or later Aprilias. So everything is a bit different here. It depends to the size you want to have or if you like redneck solutions by simply adding holes where in need. Here the bolt pattern with original rear sprocket: I did not like the original 13 / 38 teeth set up with a 0.342 ratio it is for my taste too fast. As it is not possible to find any ressource for a good trials set up I started to try it out myself ... I tried out a 12 / 42 teeth (0.285), still a tiny bit too fast, then a 11 / 42 teeth (0.262) which was a bit too slow, (and I wanted a smaller rear sprocket). The 11 /42 can be seen below, I took a climber sprocket and just drilled additional holes ...seen here I have now custom fabricated a 40 teeth rear sprocket to fit the 11 teeth front 0.275 which I think will suit my needs. The sprocket above was made by alphatechnic in Germany.