johnjsy

Hi Jonny, the standard chrome lining was never all that good. There are companies who can skim out the hub and press in an iron or steel liner. I have seen mention of getting the shoes lined with the stuff used on fork lift trucks, apparently if works well. Have a close look at the actuating cam in the brake plate. If at all worn, get it reamed out and a bronze bush installed. If left worn it only tends to tilt the brake shoes sideways a bit, hence poor brakes. Stick with the standard Amal levers, they work best. Either original forged ones or much cheaper pattern ones,available from Bultaco U.K. — In Motion. They have the correct cables as well. I use either Amal T 80-200 or Domino twist grips on all my Bultacos, much neater than the older style ones. Just to mention, put the ignition condenser up under the tank, much cooler there, Clean all the coil to frame fittings, rust is a poor earth conductor ! Hope this helps......

Yes, no problem. 1976 / 77. Alpina 250. Bore 72mm X stroke 60 mm = 244 cc. Great bikes, if mostly complete, get it. O.K. ?

In Motion do a much more up to date ignition system with lights, 12 volt I believe. Worth a look ?

Hi Dickie, I use the SKF bearings you mention in all the motors I build, and to date not one has failed. It is interesting to note when a main bearing does fail, it is nearly always on the ignition flywheel side. A roller bearing such as this has far more strength than an ordinary ball bearing of a similar size. One thing that is a benefit, no need to heat up that case when you are ready for assembly, just pop it straight on. Hope this helps..........

Hi, Kevin Brendon Racing is a good place to have a look. Although his Bultaco listings start at 250, there may be a close match for a different. The Montesa ones start at 61mm, well worth a look. When you get fixed up, post again on here, the info could help others.

Hi there, from your picture the carb looks pretty mucky. Find a local dealer or firm who does ultrasonic cleaning. Old fuel sitting in a carb is bad news, the small drilling’s get gummed up, get it cleaned then rebuilt with new gaskets to do the job properly.

If it is old fuel, drain off, mix up new. Squirt brake cleaner, or rocket 40 or similar down the carb. If the timing is right, it will fire. No choke when doing this. Hope this helps......Ps. Do this outside, burnt brake cleaned fumes are rather nasty, avoid breathing !

Easy ! I had a M 89 , 1971/72. 125 Mk.5 Pursang. I used it for blasting up our local hill climb. A really good bike, good memories, enjoy yours.

No, Jaime. The Sherpa S was an out and out competition model. You could fit a points plate and flywheel from say a Lobito or Alpina to get lights. Your best bet is to contact Lynn and Dorothy Mobley across in Minden Nevada. They handle a lot of secondhand Bultaco Spares, and can give you best advice on this. What is your intended use ? If for off road an Alpina would be far better I reckon.

Hi Mick,lets see if this is correct.

Yes Mick, it is M30 X 1.5 I have a picture, not sure how to put it on here, going to try anyway.

Hi there Mick, 2 of my Bultacos have Motoplat electrics. I have a Buzzetti. M 30 P. It is 1.5 pitch threads. I think that is the one. Also a MCA P 157. of about 32 mm diameter, 1.5 threads. I cannot remember which is the one to use ! Maybe another reader on here can chime in with the info needed ? If by mid morning tomorrow there is no answer, I will take the cover off one of mine to get the size for you. No time tonight, we are eating soon !

Hi there Paulmac, I have just taken the top cap off the top of a spare fork, I think it is from an Alpina. The fork tube is 35mm, used on many models, and having taken he spring out, I used a 30 X 1.5 mm tap to see if it fitted, yes, that is the size. If you need to run a tap in to correct the threads, be sure to clean out any particles of swarf that may be produced. Once done, load up an old toothbrush with a grease, water pump if you have it, then starting at the bottom of the thread, slowly unwind anti-clockwise up to the top of the thread. Being a fine thread, this may take a while ! Hopefully this should pick up most particles. Hope this helps ......

Hi, quite easy to resolve, actually. The studs in the manifold are M 8 , just remove and fit the rubber manifold with Allen head bolts. The studs may be quite tight, use 2 nuts locked together to undo, also head up the alloy in a tub of boiling water for 3 or 4 minutes, or use a heat gun. You may need to turn the heads of the Allen down a bit to get clearance to fit, maybe shorten them a sixteenth or so, different makers seem to have different specs for the sizes made. Also, a smear of copper grease or Vaseline will be a good idea on the threads to prevent seizing in the alloy manifold. Essential if using stainless Allen head bolts, the 2 different metals will corrode if fitted dry. Hope this helps...........

That looks really good, Mark. How did you acquire it ? To the best of my knowledge, all of this model were sold in the U.S. I have a friend down in Spain who is doing a survey of how many Metrallas have survived, and how many. Could you give the engine and frame number, or put a picture of them, to see if this one is already listed ? Many thanks, John.

Hi, it seems to be the wrong switch. With the pin in it should be open circuit, pressing the brake pedal allows the pin out, completing the circuit, the brake light works. What is needed is a reverse light switch as used on pretty much any car. If you have a decent auto parts store near you, call in and see if you can find a suitable one. Take a multimeter with you, set to the diode range, be sure the contacts close when the pin is out. Hope this helps........

Hi, one of the locals ran a Pursang in out sprints some years ago, max speed was about 75. The limiting factor always is the size of gearbox sprocket. 13 T with a 520 chain. However, you can go bigger if the kickstart shaft is removed. Likewise the rear hub, not much you can do to fit a smaller rear sprocket, the best thing to do there is to find a hub from something else. What exactly is your intended plan ? A few more details would help, then I am sure a fellow reader of these posts may have done what what you are setting out to do. Hope this helps.......

Yes, 45 years old, but still look the business. Really nice, what’s next ? I have 5 various models, just so satisfying to own and work them.

Predictive text, always good for a laugh ! That should have been Sherco,

Hullo J, Try France trials Classic, they are on Rheims, east of Paris. I am sure I have seen a 76 mm piston on their lists. This big bore conversion brings the cc up to 272 . Incidentally, the 290 Sherlock is the same 272 cc ! Let us know how you get on.

Hi Will, rather a strange one ! Not something silly like putting all the oil in one leg by mistake ? Did you drain the old oil into separate containers ? More or less the same amount in both ? I am thinking maybe a bit of blockage, not all the old oil drained from the problem leg. Anyone else out there with any interesting thoughts ? .........

Hi bgeacook, I am not in the U.S. but on my Alpina the rear silencer is the clubfoot type fitter on most of them. A few years ago I cut it open to re/build and I noticed the small stamping sayingit was a spark arrester. If you have that kind I suggest a thorough clean with a rotary wire brush to remove any rust, to see the lettering. Highlight that with a little white or orange paint, that should be fine for tech inspection. Hope this is of help............

Dave Renham, InMotion ( Bultaco U.K.). did one for me. That should be your first port of call. How about a picture when all is done finished ?

Hi Dr- , possibly the engine had not been started for a long time, the bearings became rusty, then when thr motor was started they very quickly self destructed. Quite often a head or barrel as well if left off for various reasons, the same thing happens. Remember to use C3 clearance bearings on your re-build. Twostroke crankshaft bearings tend to run rather hot, the C3 bearings are a better choice. Hope this helps.........

Hi, glad you sorted it out, but one question. Was the felt wick still fitted ? It needs a few drops of oil from time to time to lubricate the cam that opens the points. If it is missing, or the cam runs dry the fibre points heel will wear down very quickly, ruining them. An often overlooked item !