pschrauber

The desired surface should be absolutely clean and free of grease. To clean the "pores" of the surface, I use pure polish for paint or plastic, without any wax components! Then I wipe off the surface shortly with brake cleaner or acetone, just to get rid of any grease and fingerprints. Best way to avoid finger prints is to use gloves! Before you mout the Sticker, pull the sticker off the backing paper and spray "relaxed" water to the adhesive surface and also to surface that will be later covered. To "relax" the water use a splash of detergent. Then you can apply the sticker surface without any force, now you can move the sticker / decal back and forth until it is at the right point. Then you eliminate the water away with a squeegee, this in systematic approach, (the procedure depends on the shape of the label and the surface and is sadly too complicated to explain, perhaps there exists a good How to ... video on Youtube). Afterwards warm up the ground with an ordinary hair dryer and if there might show up small air bubbles in the push them away to the shortest way towards the edge, use the squeegee to do so. (If the decal is warmed up and the aadhesive still fresh this works very fine. Then wait at least one day befor you ride or wash, ... your bike. Done and ready for riding.

Any discussion of pre-mix ratios opens the pandora box, anywhere and anytime. I do not know why, let's take it as a statement. here I can only state my personal opinion. @ BultacoSteve You are from Canada than you might know "vintage speedy", or in his full name Helmut Clasen, (He is a member of the Canadian "Motorcycle Hall of Fame" lists so I assume you might know him ?). He runs also Optimol at a ratio of 1:100 in his bikes, (That he is still racing, ....). His statement in the German Offroad Forum from 2009 where they discussed if there is any oil as good as the old MAICO racing two stroke oil that could be used in a ratio of 1:100: [url="http://www.offroadforen.de/vb/showthread.php?72676-Maico-Renn

Just to note Bultaco started in 1978 with their own 1:100 two stroke oil! So this is nothing tricky new it is vintage old. Here an articel about Bultaco motorcycles from 2002 from Oldtimer classic about the first use of 1:100 ratio two stroke oil for the Sherpa: The Bultaco Sherpa was my first "bigger" Trialsbike in 1980/81,^^ So I do remember very well these times and what we used then. In this technical "matter" it's kind of strange that there has been no development in the ratio case of pre mix gas, I would rather state we have gone backwards now ???

When Bultaco was still in business, there was a special synthetic two stroke oil under the brand name Bultaco available, it was made specially for Bultaco. With this oil you could run the engine for trial purpose with 1:100. The manufactor of this oil was OPTIMOL in Munic, they made 200ml bottles with a scale on the side for every 5l gasoline. Sadly Optimol has been bought by some US guys already decades ago, they still manufacture the oil but don't sell it here, the manufactors name: Interlube International Optimol 2-4 in the USA The Opti oil has some special treatments compared to other two stroke oils: Technical ... With a good sysnthetic two stroke oil from Castrol, Motul(France) or MOTOREX (Switzerland) and premium gas something between 1:60 up to 1:75 will also work, (I use 1:75 now, sadly my last bottles of Bultaco two stroke oil had been used with my Beta TR34 in 1987). Benefit of less oil, less carbon, less clogging up the exhaust system.

The frame number should start with two letters then a hyphen then comes 3 digits with the model number. like your mentioned 198 after that the serial number of that number, a or b models are marked by a second hyphen then comes the letter. Number as follows: AA-MMMXXXX-S A: letters M: model number X: serial number S: A or B model, (if none of this forget the hyphen and the S) Here as an example for the serial nuber of an 199b model:

Mmmh ... turn the screw in until it locks, (for turning in clockwise direction, or rechts herum in German or turning right in Englisch). Than turn the screw out 1 and a half turn against clockwise direction, or links herum in German or turning to the left in Englisch) This is the standard position for the pilot screw, (NOT the idle screw!,)the engine might run but not best, no you can finetune the by turning in quarter revolutions. If you turn to the right, close the screw, or clockwise the mixture will be leaner. If you turn to the left, open the screw, or counter clockwise, the mixture will be richer.

congratulations, a very nice bike, needs some work, but thats part of the game and is fun too. I had the same problem like you when I found my Bultaco the upper stanchions where bend and the chrome was scratched. My forks after disassembling: I looked for a second fork and found one in France which was complete and came together with the fork clamps, the price was OK. Well ... the stanchions had some rust marks and where worn out, (the lower fork legs that work as guide for the stanchions too. Here the second fork from France: After a deep breathe I decided to attack my wallet and gave both stanchions away to a company here in Germany that do real hardchrome work for machinery parts. To rework stanchions is not their daily business but there fabrication tolerances are extremly high and they can also straighten them. Here their website and normal products: Wissing Hardchrome The costs is around 110

There is so little participation recorded so far?, It's a bit strange. Just guessing : - maybe the bike is really good, no real issues, (beside the one posted befor)? - maybe only some OSSA users do have an Trials Central account? - maybe there where only a couple sold, like three or so? Maybe there are more positive effects ?

As already mentioned: I do not know how the rocker is mounted to the rockeraxle of your bike - I have no experience with Frontera or Pursang models, there where to different construction, (as I know): - A: one with bronze/brass bearings, (like model 199a and 199b) - B: one with rubber bearings, (like model 221) A: When you have bronze/brass bearings there should be inner bushings made out of steel, these are wider and should fill the gaps, soem space you need for assambling as already mentioned by John Collins. By the way the O-ring on the each of the outerside between the bronze/brass bearings is also a little bit "responsible" for the gap. B: When you have rubber inlays as "bearings", (some older Bultaco bikes, at least some Sherpa's like mine model 221), then there should be a small gap between 1-2mm on each side, for mounting the engine mount and the rocker. this gaps will be closed when thigtening the bolts of the rocker axle. I would say if there is onle litttle play around 1 - 3 mm it is OK. There are no extra spacers to mount as I know.

As you already have the rim, just to note the punches and the direction of the holes of your rim have to fit the hub and the way the spokes are mounted? (Just my two cent opinion). To the dimension, the tire is a 4.00'' wide, your other rim "only" 2.15'' the original 1.85'' so where is the problem.

You can look up here, they have sprockets front and rear, maybe they manufacture a special one on your request, but this will cost some money! Talon

No experience, I did change my rims, but took the standard width. I know it is not so easy to get Acront rims nowadays but it's still possible, even the original red and yellow label one's. If you need the ressource PM. My question to you is why do you want to mount a wider rim?

As I know the rear engine support is made out of steel, (it's steel on my model 221 and on my model 199b). There should be the Bultaco logo stamped on the outer side which faces to the tire, then it is original, (once again at least on the 221 and 199b model which I have).

Yep, 11 teeths front and 39 teeths back suits best.

Go for this gearing, just perfect IMHO and the standard for this bike and model.

Mmmh, If you have installed the bearings right there should not come out any oil, Now there is only guessing left: 1. The axis of the front sprocket spindle contains the shaft of the gear box and the clutch pressure rod / pin, like these russian puppets. May be you have something installed the wrong way from the inside? 2, Maybe you have just filled in too much gear oil? Where does the oil come out: -a between the sprocket shaft and the oils seal -b between the sprocket shaft and the inner shaft -c from the hole of the clutch rod/pin? Maybe this helps?

The speedo drive is mounted to the rear! Try Bultaco UK, they should have the parts to mount the original speedo. You can mount the speedo at the top of the fork or at the left side to the front engine mount.

Here the ressource of the fork seals from Ariete, there You find both standard oil-seals and oils seals with an additional dust cover: direct link to part list fork seals Home Page of the Italien manufactor Ariete, as mentioned already You get them from Bräuer in Germany f. e. or might be somewhere in the UK ?? Homepage Ariete It is no problem to let them stuck out some mm, the dust cover will fit anyway, at least mine do. There do exist two original late cylindirc rubber dustcovers from Bultaco one with a small loge around 5-7mm in diameter and the other one with has a logo around 12 - 14mm in diameter, the one with the smaller logo fit. I would always mount two seals and as these rings have a double lip, you can place seal grease in the gap of the lips, (when purchasing a set of them, you get a little tube from Ariete with that special grease).

Sorry I don't have any ressources for oil seals in Great Britain, only a German ressource: www.braeuer-motorsport.de They have them for example, send them an E-mail, english is no problem. But in Germany there are a lot of other places too try google: "Simmerringe Gabel Staubschutz 35 x 47 mm" The name Simmerrine = oil seal in Germany is still used after Walter Simmer, he invented these type of oil seal in 1929. It's no big problem to let them stick out some mm, the original dustcover will fit anyway. I have mounted two in each slider, btw. the older slider have a deeper skew where they both of them fit exactly: Here some pic's of my forks, one standard or original and one pair of forks modded:

Sounds very good, sometimes small things can get you in much troubel.

Have used POR15 once with best results but this paint is very pricey and difficult to apply, the paint here is from a supplier for professional workshops "Werkstatt Bedarf" in Germany suppose to be resistant up to 600

The main bearings of the crank where changed too and are installed proper? You can try out your easy checking method at leat on the ignition side. To the paint job, I have personal got good result with good heat resistand paint from the can when the silencer was blasted so no rust or old paint was left. After application you should wait until the paint is really dry and then store the parts in an oven or "heat chamber" for some hours. Ask your lokal paint shop if they can do the paint job and heat threatment for you. You will notice that the paintsurface of a heat treated exhaust is still dull but has not the same rough surface anymore which is normally typical for this heat resistance paint when applied. By the way don't apply the paint when it is too cold, best temp. is around 20

To your questions: To question Nr. 1: You should not change the float height in any direction there is only one position it works proper! Check out by turnig the carburator upside down on a table, then look at the arms of the floats that they are perfect parallel to the table. Look up the instructions book for your carburator, (still not knowing which brand and model you have for the correct distance in mm and 10/mm. See picture: 2. The main jet controlls only 3/4 to full throttle so the effect for trials riding is very low, I would opt for the standard one, best what you can do See picture: 3. The needle, I would also not change the needle, take the standard one, mine is sitting in the second noth counted from up downwards. The needle has three parts the tip with the notches, there should be 4 nothes. By changing the notch position it is possible to raise or to lower the needle in order to obtain mixture enrichment or mixture weakening over the range that is regulated by the needle taper, which is, - look up again to answer to question 2: between 1/8 to half of the throttle. Here again I would not change the needle if I do not have an real issue. You can get different needles with different cylindrial parts (look at C), this will affect the mixture strengh in the the first throttle valve movements up to about a 1/4 throttel, very useful for trialsriding, (therefor I asked also if the needle is in proper status befor too). If you change f. e. to a reduction in the diameter of this cylindrical part this will produce a mixture enrichment and by increasing the opposite. But befor you do any changes here first get familiar with the throttel response you have now and then first start changing and do some experimental stuff. (It's just my opinion you can still do what you want).

Mmmh ... Which Carburator model have you mounted to your Bultaco, just to make sure. Have you cleaned your carburator very well, all pipe and tubes inside, there are no cleaning rag or kitchen paper / Kleenex, ... left overs somewhere, (this can happend). Look at your slide inside the carb, still working proper, which means: The slide or the cylinder where the slide sits inside the carburator is not worn out, If the slide is chattering around inside the carbbode it' time to replace, if there are sliding marks an the cylinder surface you might have to exchange the carb body too. (Does happen when the carb is as old as the bike, with a worn out slide proper jettting is a pian / will not success. Is the carb needle nice and there are no signs of abrasion visible and the needle is not bent, if you see sliding marks or the needle is worn out and the needle jet too. If the needle is bent you have to exchange both parts too.