bultaco49

Came across this Movietone clip. I think there are probably more trial clips if you search the archive. http://www.movietone.com/N_POPUP_Player.cfm?action=playVideo&assetno=95964

Don't combine a resistor cap with internal resistor plugs. This doubles the resistance and may give problems especially with starting. Plugs with resistors usually have a prominent 'R' in the manufacturers code.

Try here http://www.shedworks.net/id16.html

Try Powerdyno in Germany (English spoken) They were very helpful when I wanted a specific spec Bultaco ignition (also unlike Electrex who never answered my email). They make very good sports ignition. http://www.powerdynamo.biz/eng/systems/7294/7294acinst.php

If you are assembling a flywheel on a taper shaft the woodruff key only locates the flywheel on the shaft. The taper does all the gripping. If you are shearing woodruff keys constantly lap the flywheel to the shaft and then assemble clean and dry - no oil or grease - and you can leave the woodruff key out (making sure the required torque setting is attained!) I run my Bultaco 250 Historic kart at 10,000 rpm with a 1kg flywheel with no woodruff key. Villiers - no woodruff key Powerdynamo electronic ignition (a very good German option) - no woodruff key

I'm sure Dave at Bultaco UK will have one. This part is common to many Bultaco Sherpa engines. If not PM me and I will send you one. http://www.bultacouk.com/

Hi Woody According to my M129 5 speed Kart engine stripped out on the bench it is raised boss facing outwards towards the clutch. Engine & gearbox is the same as all the other Bultaco engines I have worked on. Cog wear marks in my box of bits also indicate boss facing outwards. Tim

The Historic Karting crowd get their cables made at J.J Cables Ltd Tel: 01926 651470. I think they may have had a mention on this forum too in the past. Maybe worth a try if you can't find one.

If you do use Caswell's there is plenty for two tanks and at £50 a go its worth finding another tank to split the costs. I think there are only two outlets for Caswells. http://www.caswelleurope.co.uk/ or www.hitchcocksmotorcycles.com/news/22231//Ethanol_-_Part_Two:_The_Remedies That address is a useful article on Ethanol but go back to homepage and follow the link for caswells TIm

Here's one. Model 49 engine in Sammy Miller frame with Kit Campeon. Built in 1970. Some newer bits added along the way. Owned by me until recently.

The general description you give of assembly doesn't sound quite correct. The crank seal carriers should be temporarily bolted to crankcase then mains should be assembled onto crank. Fully assembled left side of case should be laid on supports and heated to 145oC. While hot, crank should be dropped into it. Mains should slide into position with a gentle tap (not heafty blows and certainly not pressed). Centre gasket then applied and right side of case heated to same temperature then dropped onto left case over crank & mains. Again case should just slip into position. Getting cases to correct temperature is key and assembly as stated should just slip together. As cases cool mains are gripped by different contraction rates. Bultaco UK have a very good workshop manual which describes this operation in detail and has crank assembly and check procedures and dimensions. Left case best heated with torch and right case best heated in an oven or I use a gas BBQ with a lid to avoid wife complaints. Hope this helps Tim

That bike on Spinning Wheel Classics looks to me like a 1969 engine & frame with a 73 Bultaco Homerlite tank, Sammy Miller Exhaust and much later rear shocks. Decompressor and alloy air box are not original.

Hi Pat Nice find. Here is a Belgian site that mentions the Jean Crosset entry http://www.classicenduro.be/bultaco1970-1.html Tim Norwood

The frame in Blackcats article is a later version than that in Zisco's or mine - and was a bit of a handful for the reasons stated! The earlier frames had a single pillar under the seat (picture below) much like the later model 49 & model 80 and was very similar to model 80. Frame had a tendancy to break at the base of the headstock gusset Tim

The Miller frame has to be considered in the context of the time it was introduced. Sammy Miller designed the frame in the late 60's when the Model 49 was in production. Also Sammy was a Bultaco works rider and more or less unbeatable. Much of the Miller frame and the slimline tank was incorperated into the Model 80 with the exception of the bash plate, a mod that would not appear on the Bultaco for another 9 years. Sammy also had the benifit of much better quality and lighter steel tubing than was available in Franco's Spain. I have ridden a Model 49,a model 80 and and currently ride an un-modified 1970 Miller framed Bultaco. Can I tell the difference? Its better than the Model 49 but the Model 80, not really. The frame was used with much sucess in the bikes in Sammy Millers team and Sammy himself as he withdrew from the Bultaco works ride. Having said all that I sought out a Miller frame for my Bultaco out of respect for a rider, Sammy Miller who I remember being way ahead of the game in 1970. The frame is what should have been fitted to the model 80 and therefore makes it interesting and desirable. Sammy was also a businessman and who can deny him the opportunity to use his hard earned position to promote some 'products' - a commonplace situation these days. I'm not sure changing the head angle and shock position is adding anything to the frame. It is not going to handle like a modern bike - its way to heavy for a start and built primararily for sections that don't exist any more. Its a design looking back to the era of the heavyweights rather than to the later, lighter twinshocks and mono's. Tim

What! I raced a Lotus Elan in 'Classics' and currently race an Historic Kart (Blow Hustler/Bultaco) and I can assure every one that the rows over elegibility and modifications are every bit as vociferous across the board in classic motorsport. In Historic Karting we are banned from having any anodised parts! Their club forum is a very fiery affair. However, as with trials, come raceday we all seem to have great fun! Good luck with your rebuild

Hi Ray If you click on the link below it will take you to the DVLA page where you can tax your bike/declare SORN online. If you click on either of the orange boxes on the left to declare sorn or renew tax it should tell you the current state of the bike's tax. If the transfer of the ownership has not taken place it may not show yet. Just to add another spanner in the works the DVLA have had a large quantity of blue registration blanks stolen and are in the process of sending out new red forms to update everything which has the effect of slowing DVLA even more than normal. https://www.taxdisc.direct.gov.uk/EvlPortalApp/app/home/intro?skin=directgov Tim

Hi - If you take one of the bearings out it should have a number on side of the outer race. If you go to a site such as https://simplybearings.co.uk/shop/index.php enter the number in the search facility and a selection of bearings should come up. This company supplies good bearings so an 'economy' bearing will be good enough, or you can order a quality bearing such as SKF at an incrased price. They supply metric and imperial sizes. If no number is present there is a facility for entering bore, diameter and width and this also will give you a choice of bearing. If you are still stuck ring them or email them as they are very helpful. I would recommend a sealed bearing for your wheel which can be identified by looking for the letters 2RS after the identifying four digit number. If you need to know a little more about bearings read the FAQ page (product info). Hope this helps. Tim

Hi It is a very good sealer for fibreglass tanks. I have used it on 7 tanks now over 6 years and no problems to report. You have to order it by phone from here http://www.caswelleurope.co.uk/gastank.htm Or online from here (and a good document to read too) http://www.hitchcocksmotorcycles.com/news/22231//Ethanol_-_Part_Two:_The_Remedies There is enough for two tanks so find a 'buddy' to seal another tank as it is pricey. To clean tank I use marine clean from Frosts http://www.frost.co.uk/ Amazing the crud that comes off! Tim

Here's one http://www.classictransfers.co.uk/pages/picture-galleries/british-us-transfers/s---z/sprite.php Very good service from them in the past Tim

Martin I can see I havn't converted you, so.. Apart from sorting out Bultaco and Historic Kart fuel tanks I also fibreglass roofs. We go to a lot of trouble to ensure all the mat is enveloped in resin (not gel coat - I'll come to that) which ensures that the styrene in the resin softens the mat so it can be moulded properly and the fibres are fully enveloped in the resin when curing and setting. This also gives fibreglass its strength. Saying that un-saturated mat is nothing to worry about is an excuse for a poorly laid up job. The inside face of a fibreglass matrix should be smooth hardened resin fully enveloping the mat. Not flat smooth like the outer surface, which being the finished surface has 'gel coat' either applied to the inside of the mould first and the mat and resin applied while tacky or as in the case of roofs, painted onto the curing fibreglass . Gel coat is, as you obviously know the finished face of the fibreglass item with either the colour in the gel coat or for a paint finish. Getting back to lining a tank. If a prduct such as Caswell is used it is in effect like a 'gel coat' on the inside of the tank but as it has no styrene in it it will not form part of the fibreglass matix. I suspect that in the extremely unlikely (in fact it would not happen) event of one of Paul's (Shedworks) tanks having unsaturated fibreglass on show on the inside of one of his products a replacement would be forthcoming. And, just to be on the contraversial side I would say that a ethanol proof fibreglass resin has not yet been produced! Tim

Hi Martin Look inside the tank through the filler cap. The inside of the tank should be a smooth finish with no glass fibre mesh on show. If you can see a whitish mesh then the resin has been etched away and you may not be experiencing problems because little resin is being dissoved now and carried to the carb and engine but ethanol will still be dissolving the resin. In the end the paint finish on the outside will begin to bubble especially at the seams and in extreme cases fuel will leak. Ethanol problems with glass fiber tanks is a real issue - not an urban myth -. If you don't believe me Google the subject and look at the replies, for example, from the Marine industry and you will see similar forum threads to this and whole reports on the subject from reputable. Here is a link to a good one http://www.boatus.com/seaworthy/fueltest.asp . It is such an easy task to line a tank. Clean it, dry it and line it then no worries about the issue 'urban myth' or not. Tim

Hi Johnny Before you use 'kreem' products to seal or line your fibreglass tank check with the manufacturers that is is compatible. If you Google Kreem and fiberglass together many users have had problems with getting Kreem to adhere to fiberglass. In all the adverts I have seen, where they mention it, Kreem refers to steel tanks only and unless they have a new product out beware. Kreem is extremely difficult to remove from a fibregalss tank if it delaminates(I speak from experience)as Acetone is the recomended solvent. Acetone will also dissolve the fibreglass resin. There are products, such as Caswell, that specify use for Fibreglass tanks and will protect against ethanol. Ethanol will attack the fibreglass of a Bultaco tank, again I speak from experience. You must line it, use ethanol free fuel or drain all the fuel between uses. With all tank liners and sealers, if it does not say it is compatible with a fibreglass tank it probably is not. The best cleaner for tanks (that I have used many times on fibreglass tanks) is 'Marine Clean' available from many places online. Many recommend acetone but this is difficult for the reasons mentioned but also it will take the paint finish straight off. Using pump fuel is no good as it will leave a residue of solvents and petrol that will make adhesion of the liner/sealer less effective. Tim

Hi Paul You have an early (series 1) Model 92 with the correct frame. The frame was modified mid production of the model 92. If you Google immage the model 80 (the previous Sherpa) you will see the layout of the frame you have. There are lots of other items which are incorrect on the bike if you are keen on having an original model 92 Sherpa but the important thing for a basis of a rebuild is that the frame and engine numbers are simmilar (they should match but many Bultacos are a few digits out). If you just plan to use it at twinshock events you will soon find that unfortunately the bike is very uncompetative against the late twinshocks (Yams & Fantics) but the Sherpa is a fine bike and fun to ride and there is no twinshock as smart as a slimline Sherpa. If you can find a copy of 'Historia de la Sherpa T' you can see all the Sherpas and the changes. Best source of spares is Bultaco UK, Sammy Miller and ebay. Whats the Lotus reference? I had a series of Elans at the same time as owning my Sherpa's. Tim

Hi Brucey I don't think any of the vinyl ester resin producers or manufacturers of products using vinyl ester will guarentee their products as resistant to ethanol(which is the 'bio' element current unleaded). If you use your fibreglass Cub tank with pump unleaded you should line it with a product that does guarentee ethanol resistance as not only does ethanol dissolve fibreglass, the gunk it turns into will clog up carb jets and galleries. And just for good measure, drain the tank anyway when not in use as Bigshiney suggests. Tim