triple_x

Billet Parts or Bultaco UK. Martin

Hi It would be an unfair test, as on both my hubs the previous owner had gone straight through the chrome lining into the aluminium. So I was left no alternative but the skim out and sleeve. However the brakes did improve after skimming with use, and are now fine. Regards martin

If I compare the brakes on my Street Triple with the Sherpa then the Sherpa's are non existent! However back in the sixties the brakes were adeqaute. But I think that we must rememeber that these bike were launched 45 years ago and the likes of Miller, Lampkin did not have any issues with them. Today, however they are compared with modern bikes with disc systems incorportating Hydaulic calipers. On my Sherpa both Hubs needed sleeving, but one difference was that I got the brake shoes skimmed (in place on the brake plate) to exactly match the bore diameter of the sleeve. Once bedded in they where fine. So try getting them skimmed. Hope this helps. Martin

According to Historia de la Sherpa T The Story, Chrome-moly tube was not used until frame no 9100727 and for the 350 9202387. I think that was after the removal of the triangulated tubes from the vertical upright the rear side diagonals (from footrest to top shock mount). Martin

Hi Woody I think my main problem was being out of the (trials) saddle since the Perce Simon in 1973. I am doing the Harry Perrey so i will be pleased to let you have a go. This time I have entered the Open class. The barrel was butchered by a previous owner who attempted to take every other fin out! I think he was using a chainsaw, any way I did my best to tidy up what was left. The engine is an 80 prefix. A fellow rider on an 84 Montesa suggested that i take the tickover off and that helped, but as you may of noticed I was not in control!!! A couple of things, i could not get used to the position of the back brake lever and kept missing it and whilst my previous experience told me what to do I simply could not put it into practice. But what the hell I had a great time and both bike and I came back in one piece!!! Look forward to seeing you on the 17th. Martin

Bultaco UK supplied a model 125 rear box which is straight through and quietens it down to acceptable levels. So off I went to round 1 of the SM Champoinship and apart from entering the Twinshock class instead of the Open class easier route had a smashing time. The bike lasted and I had a complement from Sammy Miller on the condition of the bike and sound of the engine. Whilst I was out of my depth on the hard route I found that in certain sections the engine would not pick up cleanly from very low revs. Now it was so much better than before, but still not quite right. So I am looking at the easy stuff, one rider said he thought my bike was geared too high for the tighter section of today. Gearing is 11 front 46 rear on a 520 chain. Another said he thought the carburation was a tad weak at the bottom end (30 pilot jet). So all in all I was very pleased to go from rebuild to finishing a National trial (all be it last) and to be nearly there with the engine. So if any of you guys have thought on the gearing or Mikuni settings I would as always appreciate you advice. Kind regards Martin

Hi Majesty Your comments are encouraging. I always thought that Bultaco knew what they were doing and I remember the Campeon parts being a very popular upgrade. I also remember a lot of riders throwing the little back box away because either they did not like the way the bike pulled or because it jammed on the rear tyre if you had an off and dropped the bike on the silencer side. I am quite prepared to accept that the bike will run with it but it is just knowing where to start, jets or timing. The bike had a brand new Mikuni fitted two weeks ago (supplied by Motocarb with spare jets) and whilst it starts easier using the cold start lever it still appears strangled pulling from very low revs. I realise that the pilot jet works to around quarter throttle but I have done the basics. Marked the twist grip movement into 1st quarter rotation ( Pilot) next half (needle) and final quarter (main). Then i have run the engine constantly in each range and removed the plug and it is the correct colour (a nice mid brown) so think the jetting is correct. Timing I believe is correct 2.8 - 3mmBTDC It has a new air filter. So i am left with the belief that with the back box fitted it is restricting the breathing. I will probably rework an old clubfoot tailpipe that I have and give that a go! What worries me more is that we get enough stick riding off road without being a noise nuisance. Thank you for your comments much appreciated. Martin

Thank you, both. My son took the box to work and they put a miniature camera inside. All they found apart from swarf, was two diagonal sheets of steel plate spot welded at inclined angles with a small gap at the top rear end of lower one and the front lower edge of the top one. Thus forcing the gasses to go up, down and up in order to escape out the tail pipe. Not good for gas flow! So apart from spending

Hi My target was to bring my Sherpa back to original Kit campeon spec. To this end i have fitted a new middle box and a new triangular back box (both supplied by Butaco UK). When the back box is fitted it kills all low speed response and it feels like engine gets bogged down until it about 1/8 throttle, also it does not want to start. Middle box outlet internal dia is 22mm dia and back box inlet and outlet bores are app 19.5mm dia, would a reduction of 3mm cause these problems? Remove the back box and all is fine, a bit loud (96 decibels) but it really works well, fires second or third kick and runs sweetly. I do not want to be refused a start because the bike is a tad too loud, so I am wondering where to go next . It has a model 80 air filter with new element, new Mikuni carb, absolutely no air leaks and the colour of the plug is the right shade of brown, timing is set at around 3mm. I did a refresher day with Steve Saunders and he told me to get rid of the rear box but at the time it had a Concentric MK1 and I thought the Mikuni may have put it right and let be go back to original complete system. I tend to believe that it is the increase in back pressure that is causing the problem. If this is a known problem with this type of back box what is the remedy other than getting a club foot tail pipe. any comments would be appreciated. Regards Martin

Hi I had no trouble with the points set up. However with limited time to fettle I was advised to go the Elextex world route and I have to say that it is a superb bit of kit. Timing starts @10deg then advances to 23deg (3mm BTDC)when running. The logic is that the bike starts easier @10deg. You pay you money and take your choice! Martin

Hi The simplest way is to fit longer rear shocks. By increasing the rear shock length by 20mm (360mm length shocks) this should sharpen the head angle by 50seconds (nearly a degree) if my school boy Trig is correct. TAN B = 20mm/1315mm(std wheelbase)=0.0152091. Which on the table of natural tangents relates to app 55' or nearly a degree. It is a normal trick we do on the road bikes. I fitted a longer shock to my Street Triple and it really quickened up the steering. Beauty of it is you have not altered the frame and if you don't like it put the old shocks back on. Foot rests are my next project but I want to learn to ride competitively before I fiddle and make a major change. good luck. Martin

Interesting and comforting that another owner has the same issues with the Kit Campeon rear box. Is there a solution apart from ditching it or using it solely for display? My thoughts are to change to tube diameters to match the exit tube from the middle box. My son is putting a boroscope in the box Monday to see exactly what the internal layout is. I suspect it is just two tubes (1 in, 1 out) with two diagonal baffle plates. Any advice would be welcome as currently the bike is a tad loud. Martin

I agree I have the standard SM Betor's @340mm which work really well. My Sherpa pushes in tight corners so I will be fitting the 360mm next week Martin.

The supplier was www.elextrexworld.co.uk. kit STK-154 Very simple to fit just line up to the centre line of stator plate screw (2 o'clock) with the centre line mark on stator plate, then the difficult part check with a strobe. Have just got back from a training course with Steve Saunders, absolutely excellent day. I cannot recommemend it highly enough. The whole day gave me a real buzz. I did it because my last trial was the Perce Simon 1973 and I thought i may be rusty. I truth I think I was more than rusty. Anyway back to the bike. With the full Kit Campeon Exhaust the bike just would not pick up under load from from low down. Steve suggested that I remove the rear triangle box ( I could not remember any of the works bikes using it ) it immediately improved 100%. It is not perfect but it is a lot better. But I was pleased for a ground up rebuild to run without (Exhaust excluded) problems for 5 hours and ride through at least 40 section. Boy am I out of condition, my legs were totally shot by the end of the afternoon. Regards Martin

Hi First of all thank you all, for your help and advice. The jetting is correct 20, 106 and 160 slide is to spec. Monday I stripped tha carb down, yet again and none of the jets were blocked! So i got my magnifying glass out and looked at the bores in the carb and all appeared clean. I then blew compressed air through, took the pilot screw out and found a piece of alloy swarf in the hole removed it replaced the carb and it started third kick and has done since. It is still a bit weak until warm but other than that is sweet. One other point the CDi unit had to be set at 10deg BTDC just under 1.5mm BTDC. Apparently this is to make starting easier it then advances to 23deg or 3mm BTDC when the engine is running this is to provide a better spread of power. Appreciate all of your comments. Regards Martin

Thank you all for your help. This afternoon i stripped the carb down and could not find any evidence of blocked jets. Have not yet had a chance to get it started (make the bed, polish the shoes, empty the dishwasher and cook the dinner) It was valentines day!!! I bought the carb from Bultaco UK it came in a white box with proper Amal logos. Unfortunately i threw the box away, just trying to keep the garage tidy. James @JHS has said that it is not getting enough fuel to cold start. On all his vintage rebuilds he uses the MK 2 concentric even though they are not original, one can at least start them. I will get it all back together Monday evening and advise. Thank you all for your time. A problem shared is a problem halved. Have good week, oh by the way I have booked a days training with Steve Saunders next Saturday to see if @ 61 I can still hack it feet up. Kind regards Martin

Hi I an running out of patience with the Amal Concentric. To explain the background on my ground up rebuild my target was to get the bike original in all things. To this end I purchased a new Concentric Mk 1. It is Jetted correctly runs realy well when the engine is warm and then always starts first time. However when cold it is B**** and needs 20 - 30 kicks to get going. It tickles up with fuel over flowing so there is no fuel shortage. Sammy Miller, James @ JHS racing have told me I am wasting my time as the cold staring design is poor, and to get a Mikuni or DelOrto, well ok that may be the route. But surely Bultaco would not have put up with this problem when they sold new bikes. All seals, bearings, gaskets are new and from the airfilter through to the barrel is airtight and the Exhaust is totally new, also I use an Elextrex world CDI ignition and the timing is correct, the plug is as recommended by Dave Renham. Do I just give up and go the Mikuni or Dellotro or am I missing something. As an aside my Anglian over the two years of use (66 - 68) always started. Comment would be appreciated. Regards Martin

Hi We all have our own preferences on rebuilds and whether to use sealant or not. Simply put it depends on the quality of the machined faces. In my case on the M80 engine I just rang Bultaco uk and got a complete set of gaskets, seals and bearings, simple. In my research I did suspect that some of the gasket sets available were too generic and did not include all the bits. On final assembly I just spread grease along the mating surfaces, this has three purposes 1) it holds the gasket in place 2) it allows me to strip the engine down without having the scrape goo off the surface 3) I may be able to use the gasket again if I have the do a field repair. Back in the sixties on my Greeves ( Scottish, TES, Anglian) I used Wellseal as it came off easily. Hope this helps, but there are many ways the skin a cat. Martin

Hi Model 80 does not require a head gasket. Just make sure the mating faces are clean and smooth. However my 198 does! Martin

Hi I have got exactly the same lines on my M80 crankcases. They are simply the die/mould break lines so that the cast crankcase can be removed from the die once cooled. They are located by the redundant speedo drive and drain plug. I suspect there were pins in the tooling to form a holes prior to drilling out and tapping the finished spec. If you look at an Airfix kit you will always see the tooling lines as well as ejector pin marks. Hope this helps. Martin

Hi I was very impressed by the pictures and video of the El Puma Bultaco. But they set me thinking. When i watched the Perce Simon last year I breifly made a comment to a James rider that his bike looked and handled nothing like the James 250's I remembered in the early 60's. My comment was not critical but one of admiration as to the level of preparation. But it does beg the question "Exactly what is a genuine pre 65". And now what is a genuine Sherpa judging by the pictured version with ?Beta forks?. I have two Sherpa, a 91 (road reg, ground up rebuild) and 198-a. I intend to keep the 91 original but am tempted to play with the 198-a perhaps starting with the head angle but wish to know how much the alter the angle or whether to just increase the length of the rear shocks. Good video and pics thank you. martin

Hi I had the ex Paul Dunkley Cheetah, and last rode it in the Perce Simon 1973 (i think). Retiring with a broken gearbox, a large stone got caught in the chain and jammed up in the front of the gearbox sprocket, breaking the case. Anyway if you want me to email a picture of the bike, unfortunately with me sat on it in 73 I will. Regards Martin

Looks good to me. Mine was a disaster in March but is now road registered, with 20 miles registering on the Halfords bike speedo. I am now, at the age of 61 thinking of taking up Trials where I left off on 1973. Had a cracking 6 months, full of learning, tears and the joy of hearing it start second kick. WOW!!! Dave and Pete at Bultaco UK were absolutely excellent always finding time to talk me through the queries. Have fun. Martin

I am just about to put my Sherpa model 91 on the Road. Local DVLA were most helpful.

Hi Peter. Thank you. Martin