lorenzo

WD40 was never designed as a penetrating oil and is virtually useless for this task; you need to arm yourself with a proper penetrating oil, such as Plus Gas formula A.

Isn't it true that Bultaco used solid copper cyl. head gaskets across the range for a short time? I can confirm that (at least) Pursang Mk. 9 250 & 370 and Sherpa models 198 & 199 had gaskets as standard, as I have some. They were not included in OE gasket sets for these bikes, either. However, as I am unable to access my parts info. at the moment I cannot say when they were phased out; my 199B has a spigoted head joint just like the Bulto engines of old. It's conceivable therefore that a model 198 had a gasket, "A" and/or "B" variants did not. To give you an idea, here are some Pursang gaskets (250 top, 370 below) :- (I'm unable to photo the Sherpa ones at the moment, but they are very similar.)

Thanks, Greeves. Very interesting..........

Referring to the 198 series numbers provided by Greeves - anyone have the equivalent numbers for the 199's ? Or know when 199B numbers started ?

Penno - Not sure if this helps, but here is an original blue Sherpa tank that I have; it has "1979" moulded into the underside just like yours:- This one's never been on a bike, and so I believe actually looks as close to original as you are likely to see. You can see that the finish is completely matt, as pointed out by Nigel.

"Out of stock" - and have been for quite a while...........

motovita - Woody's list is pretty comprehensive (and impressive too, if done from memory!). May I add : Both gearbox internal ratios and secondary drive ratios are different - few, if any parts are truly interchangeable . Model 92 does not have a gearchange thru shaft (r.h. shift only) In addition : Entire rear wheel is different - model 92 is a much heavier lump altogether. Carb. and airbox setups are obviously completely different.

Hi, Jeff - Nice looking bike ! Regarding your earlier questions, it's a model 92; first of the 325's and known as a T350. Fenders are certainly Bultaco OEM style, but on a bike of its age highly unlikely to be originals, unless it's never been ridden in the dirt! Amal 625 is the correct original carb for this bike and standard settings were :- Main jet 150 Pilot jet 20 Needle jet 106 Slide #3 Have you managed to get a spark yet ?

Lance - Who's a lucky so-and-so ? Ooh, I just love a story with a happy ending...........!

Some further info. re 198 models as they left the factory - Frame with bottom tubes and welded bash plate used up to serial #19801769 Frame less bottom tubes and with alloy bash plate factory-fitted from serial #19801770. (according to the appropriate parts book, and unless someone out there knows differently, of course)

Lance - I echo what TooFastTim says regarding finding a bush - which definitely seems to be missing. At this point (if it was my bike), I'd be quite concerned about what else may have been simply cobbled together for the sale, including fixings that may have been left loose - or missing, and so on. The sprocket nut lockwasher has not been tabbed over - there's a dead giveaway, I feel. I think I'd be checking the rest of the engine and/or bike over in very close detail - even partially dismantling, if need be. (I'd replace that sprocket, as well.) This way, a possible mechanical disaster could be averted, but then - it isn't my bike..........

Motovita - Please don't lose any sleep over your alloy mounting - it may well be perfectly OK, of course. You will see readily if there's been any engine movement at this point when you dismantle for painting, anyway. My own bikes that I referred to earlier were bought on the cheap and were previously owned by guys for whom "maintenance" was an alien concept, apparently........ The steel bracket is an original Bultaco part, introduced (I think) on the the later 198a/199a models; it was certainly in use by the time of the 199b. I imagine it would be available through your usual parts source(s).

bondy - You fixed this leak yet ? A couple of thoughts - if it's leaking just standing, it points to incorrect assembly on your part. On the other hand, if it only leaks after running or riding, it may be pressurising because the g/box breather is blocked - particularly if you've overfilled it with oil. If you look at the left hand crankcase just above the boss for the kickstart shaft, you should see a small drilled hole - make sure this is clear. Hope this helps.

bondy - The engine rear mounting bracket was originally alloy. This was a casting, with only limited ability to "nip" the rear of the engine, with the almost inevitable result that the engine would end up "loose" in this bracket. If left unattended for long enough, the vibration/movement of the engine could wear the inner faces of the bracket and make the problem even worse - and then the head steady would probably break as well. Hence the change to a STEEL bracket - a great improvement, in my opinion. (On all the Bults I've owned with the cast bracket, I've replaced with steel, as the originals were worn beyond saving by "loose" engines.)

Penno - You don't say on which side the small-end spacer was "eaten", nor how/why the piston crown was damaged. I think some con-rod side play is intentional and necessary because of the design and nothing to worry about. However, "excessive" side play could indicate wear (or collapse) of a big-end thrust washer (if fitted), maybe as a result of, as already suggested, a bent rod...............

Hi - "Sherpa 325", I think you have it.......... Not checked out 182 & 190 models, but a little time spent with a parts book for 158 & 159 models revealed a large number of differences between 250 and 325 variants, as you stated. (I'm assuming that a different part no. does actually mean a different part.) I think I'd largely overlooked or forgotten about these differences as all my more recent involvement with Bultacos has been focussed on later 199 bikes - thanks for reminding me.

Hi - My first (last) posting concerned head steadies; continuing in a similar engine bracketry vein, can one of you knowledgeable Bully fans tell me what the bracket on the left fits? This places the swing-arm pivot about 1/2" closer to a line through the engine mounting-bolt hole centres than the Sherpa 340 bracket on the right (which has the same hole spacing as the older-style alloy bracket 159.10-064). This the second time I've bought one of the these unidentified brackets (sight unseen, of course) and was assured by the sellers in each case that it was removed from a Sherpa; I had a feeling they were Pursang, but the only MX one I have is different again, as the s/a pivot is vertically offset :- So, I wonder, how many different brackets were there on the Sherpa range ? Any info. much appreciated.

Hi - I'm new to this forum (my first post), having only recently discovered Trials Central. I have an early Comerfords 340 and have followed with interest the discussion on the "improved" head steadies, as this was one of the issues that concerned me when I first acquired my bike back in the eighties. Here is the steady as it came with the bike :- I recall querying this with Comerfords and the guy I spoke to told me they had experienced a number of breakages and their "improvement" at the time was to "weld in a thick piece of rod", and gave me the distinct impression that this was indeed done very early on - when they still owned the bike......