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lorenzo

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Everything posted by lorenzo
 
 
  1. Mark - If you need a wiring diagram for any old bike, a good place to start looking is in the maufacturer's OWN literature (if this available), rather than aftermarket manuals which in the interests of sales appeal try to cover a whole range of different models/years/markets, etc. - a task at which they are inevitably doomed to fail.. I've made a scan of the wiring diagram in the original OE instruction manual supplied with UK-market Alpina 85 bikes. There you go :- Incidentally, an identical diagram also appears in Sherpa 91/92 instruction book; it may be of use to UK owners of those models.
  2. Larry - Too much time on your hands ? Doesn't seem ever to be the case for me............... Some of the engine rebuilds "pending" :- Have a nice day Lorenzo
  3. Bondy - ref. the pic. in post #55 - is that a new cylinder liner ? .......Copper head gaskets no longer made, eh ? I'm glad I bought some when they were still available (and possibly less expensive). I think the last time I saw any for sale they were about £20+ each, although Bultaco UK offers an aluminium version at £15.99. Done no actual work to the bikes beyond sorting out what needs to be done, and in what order - organising parts, etc. You know, all the boring stuff.......
  4. bondy - The spacer is #39 in this parts book illustration - the trouble is, if you don't know it's there you remove the top bolt and before you realise it, the spacer rolls away down its custom-made chute (the frame bracket) - never to be seen again....... The part no. is 138.10-119 and it's described as a bush.
  5. scot and bondy - Show me yours and I'll.........well anyway, here's mine - as fitted to my 199B when purchased. Apparently this was the "fix" adopted by Comerfords (the UK importers) on their own team bikes and approved by them for other users. Make sure the distance piece is in place in the 'U' of the frame bracket when refitting the top bolt - it won't tighten properly without it.
  6. I go along with the general consensus that the outer part of the driveside flywheel has been machined down, although I don't know what a model 188 flywheel should look like, either. However, I don't think the holes drilled in it will balance anything - least of all a plain circle flywheel that shouldn't need balancing anyway (i.e. it's not a crankshaft flywheel with bobweights, etc.) - surely the holes are for lockwiring the crank end nut.?..... As already pointed out, the two parts of this flywheel were originally welded together - I have a number of driveside weights in the shed (including a Sherpa 325 item that has what looks suspiciously like a crack through most of the weld); don't recall any signs of balancing on any of them. Disclaimer : my memory's not what it used to be !!
  7. Hey, Larry - "Show and tell time".......(a bit off-topic), but what's happened to your shop FLOOR ? Something interesting caused those cracks ? an earthquake, maybe ? or you been running HD heavywweights in there ?
  8. Steve, I recall a similar topic started last year :- http://www.trialscentral.com/forums/topic/49584-miller-exhaust-replaces-clubfoot-anyone-used-one/ A model 150, if that's the bike in question, would originally have had a clubfoot (apologies if you already know this). Are you trying to save weight ? .....or ?
  9. Derek - I looked at the pic. of the bike BEFORE STRIPDOWN. I saw that the brake was originally on the LEFT. I looked at the pics. of the bike being rebuilt and saw that the wheel had been turned round and the brake was now on the RIGHT. At this point I asked the OP "why?" I looked at the archive picture you supplied. I saw the brake is also on the LEFT, suggesting that this is the correct orientation (and supporting my original question). Or am I losing the plot ?
  10. The brake outer cable appears to be anchored to the brake plate, rather than the fork slider - wouldn't this defeat Derek's reasoning...?.
  11. Very nice - seems to have all the right bits.......any particular reason for turning the front wheel round ?
  12. ](sherpa 325)/Greg - Note your coments about M199 - I have 2 of these, (both needing work). Here is the earlier one, as purchased :-
  13. lorenzo

    Wheel Building

    Don't wanna give you banana skins to slip on, but you sure ? - doesn't sound right to me....... 198 std. front wheel is spoked to a " X3" pattern, i.e. each outer spoke crosses over three inner spokes on the same side of the hub. This applies to both left and right sides of the wheel - long and short spokes alike. As in Woody's second image... Not sure about pattern spokes, but OEM Bultaco spokes came as 18 long spokes (inner and outer) left , 9 short spokes (inner) & 9 short spokes (outer) right , meaning different lengths, by the way.
  14. trum - You don't give your location, but I'm thinking temperate climate ? Some sound advice on offer here... Personally, I would also regard removing the mag. cover now and again to check for moisture, etc. as part of my regular maintenance - even if it's a vented cover (.....and yes, even if it has electronic ignition !......)
  15. I agree with everything Woody says about this bike, and model #92 in general. The tailpipe end appears to be an "Xdusor" spark arrestor, a US aftermarket fitment contemporary with the age of the bike.
  16. +1 for this suggestion - I've also heard in the past of Sherpas using this set-up, although I never got to see one.......
  17. Yes, you can change to l/h shift, if that's your preference - it's a through-shaft, and you should find splines under that cap (hopefully undamaged if the gear lever has always been on the other side). You will need a different/cranked l/h. lever to clear the chain. Less straightforward will be the brake control change to r/h. Later models with r/h. brake have a crossover "Bowden" cable whose outer is anchored between a frame bracket above the pedal and a bracket on the upper face of the swing arm gusset close to the pivot. If your bike doesn't already have these you will need to fabricate your own, or scheme some other way. An existing unused hole in the r/h. frame footrest plate can be used for a bolt-on pedal pivot, and most owners seem to use a steel fabricated pedal in preference to an o.e. style alloy item. My own view is that from a design standpoint this crossover cable is less than ideal - **many riders complain of loss of feel, etc. and this is further aggravated by the use of pattern cables, the o.e. Bultaco item being no longer available.** **Pure hearsay on my part - all my Bults have r/h. shift, but I do also have road bikes...... with l/h.
  18. NO ! Surely he can't mean.......................?? !! .....(Torching my bikes has been suggested more then once by sneering Bultophobes - they just don't appreciate quality !!.)
  19. I wouldn't rely too much on "equivalents" - they frequently turn out to be no such thing (with costly consequences, unfortunately) Should be Champion N57R - well, again it depends on where you look..... N57R is a hard/cold RACING plug, racing denoted by the 'R' suffix - I wouldn't personally see a need for a racing plug if you're not actually racing, just trying to get the bike into some usable state of tune. An old (1987) Champion plugs application list gives : N3C std. or N3G (Gold Palladium type), for Frontera 250 & 370, without year ref. and a recommended gap of .020". (A Clymer manual I have lists Champion N12Y for just about every model Bultaco from 125-370cc, flywheel mag. or electronic, and the same gap recommended for all - .013-.017" - clearly WRONG..........)
  20. "Manual" means the Inmotion manual referrred to earlier ? (and which I don't have). Only manual I can find at the moment containing info. relating specifically to Frontera 250 with Concentric Mk. II - a "Haynes Manual #219 "..........definitely NOT to be trusted, in my opinion........not without reason are these frequently referred to as "Heinous Book of Lies" ............ gives the same figures. However, among my Amal carb. notes for Mk. II Concentric I turned up basic (general, non-manufacturer) specs. for 2- and 4-stroke use, based on the choke/bore dia. and for use at sea-level locations ( and up to 3000ft.) and with recommendations for jetting adjustments (overall reductions/weakening) at higher altitudes. For a 2036 carb. 2-stroke application these basic specs. are : Bore 36mm Needle 2F1 clip pos. 3 Slide cutaway 3 Main jet 360 Needle jet 108 This suggests to me that the "Manual" specs. you have are probably correct, and that the carb. has been re-jetted at some time to suit the p.o.'s location ; I suppose you could do worse than return the carb. to original spec. Whether NOW is a suitable time to do this, you must decide - you could find yourself in the position of having changed so many parts (and the problem persists), that you lose the plot entirely ...........
  21. Paul - Where were you going wrong ? The answer is now glaringly obvious ! Using that printout was your first BIG mistake........ Reading it through several times made my head spin ! (and I'm familiar enough with servicing CB-pointed ignition systems that I don't have to think about it) - I can sympathise with the confusion you were experiencing. To be honest, the last time I did points and timing actually on a Bultaco was some while ago, but the general principles and m.o. apply whatever the set-up - I'm relying on my imperfect memory for the Bultaco specifics here. I can also appreciate that we all have to start somewhere.
  22. lorenzo

    Old Bultaco

    "10/12 gauge" - gauge meaning S.W.G. - a BRITISH Standard ? If they are original spokes, I would expect them to be METRIC - 4mm. maybe ? Mic. them to be certain. If you plan to respoke the wheels yourself, I urge you to take as many notes and measurements as poss. before stripping the wheels (and some photos. to make sense of the measurements later, when you have hubs,spokes, nipples, etc. as a heap of bits and have forgotten). Also set wheel spindles in a vice or other firm fixture and spin the wheels to ascertain the amount of buckle/runout of the rims in both planes - if it's excessive it may not pull out - after removing tyres, etc. check also for damage generally, especially to the nipple holes and seatings. There are detailed instructions on how to measure spokes, etc. to be found on the websites of a number of specialist suppliers. OR you could simply get a reputable wheelbuilder to do the whole job for you.........
  23. Sadlotus - Your original post asks "Where am I going wrong?" - well, taking each point in turn, here's a few thoughts of mine :- 1/ "the bike had been sitting for years and the stator and accociated bits were dusty, rusty and neglected. I cleaned everything, new points, condenser, replaced the lighting coil, all seemed to go together easily." Referring to the photo......+1 johnsy's post re the cleaning. Has someone been using the joint face to lever against? Do you have a paper joint to keep the crud out ? Why did you replace the lighting coil ? 2/ "Set the points gap and bought myself a dial guage to set the timing." .......How did you set the timing when fitting EI on the Sherpa ? 3/ "Anyway, decided to check points and timing again. Points gap was a bit wide - reset that." .......How come ? What happened the first time ? In the pic. I don't see any evidence of lube on the moving contact heel, in which case the heel will wear rapidly and REDUCE the gap, not widen it. The felt pad that should lube the cam and control any excess looks rather black, by the way. 4/ "I had marked the timing on the back plate and that hadn't slipped as I thought it might have done" .......If 'slipped' means you expected the stator plate had moved, that's not very likely with three screws securing it...and marking the timing on the backplate is meaningless anyway, as you've altered the timing since - by resetting the points gap... 5/ "timing test light .........workshop manual)........ I can't make it go on/off with the opening of the points" .....Nope , when setting timing I've never been able to myself, or detect any dimming/brightening either, as the test light circuit completes itself by finding another earth. The answer for me is to use a timing/continuity buzzer, which detects the change in resistance when the points open - this allows you to concentrate on looking at the DTI only - far easier than trying to watch both DTI needle and bulb at the same time. Which workshop manual ? 6/ "Everything else works fine - stoplight, headlight, tailight, horn (haha)" ......Assuming you have AC electrics (i.e. direct) how have you wired the stoplight ? Is the stoplamp operated by one or both brakes ? The backfire/banging in the exhaust sounds like an intermittent ignition breakdown is causing unburnt fuel to collect in the system, which is then ignited when normal firing returns. There are many and varied possible causes.... Hope this helps - Lorenzo.
  24. I assume you are referring to this type :- of Spanish-made Monobloc and main jet is #30 in the illustration ? (I have the drawing, but not the corresponding parts list) I acquired a number of these jets "n.o.s" in various sizes along with some other Bultaco parts I bought many years ago, and at the time was unable to find anyone able or willing to identify them. All appeared to have been supplied originally as official Bultaco parts and were packaged and labelled as such; more irritatingly, they are shown in Clymer manuals in similar pics. of carb. and photo stripdown sequence, etc. - and not mentioned in the text ! . Bult 360 - (with apologies for going off-topic a bit) You don't say which Mk. I Concentric - size ? UK replacement, or Spanish original ?
  25. Depends on how much better you would ride with a lightened wallet... Yet another case of believing that every new technological development MUST be an improvement ? Here's a seasoned expert fitting electronic ignition to his Sherpa, in what is described as "a straightforward d.i.y. job which will improve ignition performance and consistency" :- www.youtube.com/watch?v=sJZNao4l0gU (copy & paste) ....and it took only 14 kicks to get it running !
 
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