As Steve said, frame is an early frame, from the headstock and frame tube layout I'd say series 2 model 91/92 from 1973. The exhaust chrome pipe is an M92 type and is the same diameter as later 250 pipes. It's definitely not a 198 frame.
Further supported by the use of top yoke with taper-top stanchions - (on a 198 the top yoke would have 4-bolt split clamp with parallel-top stanchions.)
On 5/1/2019 at 12:54 PM, rusty nuts said:
claimed a 1978 machine ? Stamped rm 198 .The stamping looks like it was done by a 5 year old
If the frame is stamped RM198, it probably was - that's an engine number.............
Tank/seat unit is standard Bultaco Slimline/Kit Campeon, which also matches model 91/92 from 1973.
But what has "used prop stand" got to do with a discussion about a kick start lever?
In terms of function on the machine, little or nothing............
However, you may have forgotten saying in you earlier post :-
On 3/20/2019 at 9:36 AM, model80 said:
I recently did an excerise of getting this type of Kickstart remanufactured.
I contacted a well know UK based small batch engineering company, whose work has impressed me over the years. But unfortunatley whatever way I did the maths it was never going to come in less than £160 plus p&p. Considering that the original "new" one is retailed for less £80 plus p&p, I felt is would not be worthwhile to proceed with the project.
suggesting that no one would be prepared to pay such a price (for a brand new, super duper kickstart lever, even).
The "used prop stand" reference possibly proves otherwise, I felt..............
You have my sympathy - I know from my own experience how difficult it can be toobtain this sort of information, and I'm surprised that you've had no response so far. Not at all sure if I can help , but here goes :-
Standard M91 Sherpa rear wheel is the same wheel as M92 and also (late) M85, and features 17mm. dia. spindle, WM2 (1.85 X 18") Yellow label Akront flanged alloy rim, and butted stainless steel spokes with alloy nipples. The outer spokes on the brake drum/sprocket side have an extra bend in the butted portion at the outer edge of the spoke flange - without this bend I imagine it would make achieving the required offset quite difficult. lf the chain comes off the rear wheel sprocket these 9 spokes are frequently those that get damaged.
Does your wheel have standard spokes and rim ? Is the rim itself badly buckled, and if it is, what will you use to replace it ? Is the rim correctly laced to the hub (X2's pattern) ?
Here is a sketch I made of a M92 rear wheel, mebbe 40 or more years ago - ..........I can't of course claim that these are the standard offset figures (or that I was able to measure them with any accuracy, come to that..). However, as the bike and its wheel had only about 2 years use at the time - there's hope !
Let me know if this is of any help at all, or if you need any more info.
A check on the M85 wheel gave a figure of 1.5" for the sprocket mount surface to rim outer edge, rather than the 1.21/32", but I rather fancy this is not right - I have a suspicion it's been laced incorrectly.
Johnsy - I was about to ask why you think synthetic oils are unsuitable for 50 year old engines, but b40rt beat me to it !
In the past, my own experience with 2-stroke engines that have been stored in average conditions and unused for a long time is that without exception, after being put back into use they consume their main bearings (and/or con. rod bearings) shortly after, even though those engines may have sounded surprisingly quiet and OK initially. This seemed to happen irrespective of the make of bike or brand of (mineral) oil used.
My last 2-stroke bike acquisition in May 2016 was a 1996 moped that had stood in a garage unused since 1999. With 17.5K miles on the clock, a 20 year old bike that had its first MOT when I put it back on the road !!.......This little bike that I still own and use for the occasional local errand is up to now the ONLY one I've owned that has broken the bearing failure pattern - and I'm quite convinced that the reason for this is that it has been lubed with Fully Synthetic oil from new.
Malcolm - I will tell you that Castrol R is definitely unsuitable, even if you find the smell irresistible - don't let the stuff anywhere near your rebuilt engine PLEASE..........
I feel fairly sure that the original twistgrip would have been Spanish Amal - not # 364 (a roadbike type) , nor type 16 - at least , not the type 16 listed by Burlen..............
(quote) "which has a high quality polished aluminium finish rather than the original chromed Mazak" also hints at the latter material being the earlier.
Polished alumimium ? And with a price tag of £71.82 ? Whaa ?? Sounds much more like a fancy road bike repop than a trials bike offering to me.
Anyway, while going through the shed in the summer (seems a lifetime ago now), looking for a Doherty twistgrip which I didn't find, I managed to turn up something like
ten others of various makes and types, including :-
Two Spanish Amal (Mazak) t/grips, a plastic one (like yours ?) all removed from Bultacos , and a Doherty with stripped threads -the one that I was hoping to replace.
A feature of Spanish Amal twistgrips is that the cable entry to the drum is slotted and direct (definitely NO loose ferrule to drop out and lose.
My Sherpa 4-speed parts list (a Sammy Miller copy) lists handlebars (part #10.01-019) but no twistgrip, unfortunately.
If the brake drum is 125mm. diameter, it's a Pursang wheel. (Pursang pre-mk. 9 - this used 140mm. hub/brake). Further identification points are the extra flange on the l/h. side of the hub, and yellow Akront label. This is supposedly a stronger wheel overall than a Sherpa item.
First Sherpas with conical hub were machined and polished. Later Sherpas were less "finished", retaining the extra flange and were fully painted. Spokes also changed from stainless butted with alloy nipples to steel during various iterations.
As stated by woody, flanged type rim was used to 1972, flangeless thereafter.
Mod. 80 Sherpa and Mod. 85 Alpina both had full-width type hub of 125mm. and flanged rim.
It'll certainly need brake shoes.......what state is the brake drum in ?
When the contacts open the current ceases to flow, the condenser (acts as a damper) prevents excess sparking and arcing at the contact faces and helps with the back emf. As the current to the coil has been stopped by the now open contacts the magnetic field generated in the HT coil collapses and creates the HT spark at the plug via the HT lead.
In a d.c. (battery and coil) ignition system indeed it would......... Unfortunately, a flywheel mag. ignition doesn't work like that - for the reasons already stated.
12 hours ago, section swept said:
The Buzz box is just the same as using a multi meter set to continuity...the bleep or buzz...indicating current flow or a complete circuit, the bleep cease when the contacts just start to open indicating an open circuit..no current flow.
The buzz box is NOT just the same as using a multimeter, as the bleep or buzz will continue to sound, but change note - the whole reason for using it is that when the contacts start to open there is still a complete circuit. - look at the circuit schematic again, in particular the ignition coil. You will see that there are two coils (l.t. and h.t.) either side of the core.
12 hours ago, section swept said:
Testing the resistance through the points (across the contacts faces) indicates the condition of the points, high resistance to current flow = poor contact condition therefore a low resistance would be indicated on a new or refaced set of contacts
That's quite correct..............But that's not what a buzzbox does. We are not testing resistance or points condition, but indicating a change in resistance in the circuit when the points open.
12 hours ago, section swept said:
with the contacts always earthed they could not act as an on/off switch which is what their function is. This would mean the HT coil would never be able to create a high tension spark at the plug because it is always in the charge condition. You need to break the circuit to enable the magnetic field generated to collapse!
That's your reasoning, but once again you are describing the operation of a d.c. (battery and coil) ignition.
12 hours ago, section swept said:
By your reasoning, etc.
I'd love to be clever enough to claim it as my reasoning - I'm not.........and it isn't.
If you don't believe an a.c.mag. flywheel ignition system could possibly work you have failed to grasp the basic principles. I admit I struggled with it myself before getting my own buzz box
I'm rapidly running out of ideas to convince you........
The reason you are having to remove the c/b. points wires to show when the points open is because you are using a continuity meter/ohm meter.
In a flywheel magneto such as you have the condenser and h.t. coil are connected in parallel to the l.t. coil windings, which means that regardless of whether the contacts are open or closed, you will still have continuity. (Effectively, the contacts are always grounded........)
On 11/7/2018 at 3:50 PM, section swept said:
You should be able to put a PP9 battery wired to the contacts to either show a break in the circuit when the contacts open using a torch bulb or a multi meter set to either continuity as you have already done or set to 20v to show on/off when contacts open. With the correct wiring connected as soon as the contacts begin to open you should see the multi meter show no continuity.
You should have one wire from the contact breaker insulated side going to the HT (high tension) coil and the condenser connected in series with this wire. The other wire from the LT (low tension) should be earthed. I’m sure Montesa use a black wire for the live, although not so sure about the earth so I would find a wiring diagram to confirm the pink wire is correct. Keep us posted.
This advice would apply to coil and battery (D.C.) ignition NOT flywheel magneto (A.C.) ignition in discussion here.
On 11/7/2018 at 3:50 PM, section swept said:
When you get the sort of results you have it usually means the generator ignition coil is faulty.
Clearly, no it doesn't......
To time your magneto the accepted method is to use a timing "Buzz Box" which will indicate when the points open using a change in resistance, rather than an actual break in continuity. Additionally, if you are using a d.t.i. or timing stick/plunger in the spark plug hole, it's an awful lot easier to hear the opening point than trying to watch the flywheel/contact points/piston position indication, etc. all at the same time !
I have a 1960 (road) Bullet - a long-term project for which I have struggled to find correct front fork parts......I am reliably informed theyv'e all been snapped up by the pre-65 Trialers !
Your chances of finding a complete and correct, ready-to-use gearbox assy. (or one in any sort of condition, come to that), I would estimate at zero or less - but what do I know..?
First port-of-call for anything Royal Enfield has to be Hitchcock's Motorcycles Ltd., although I suspect you already know this.
A picture speaks a 1000 words, it's said - any chance of seeing your bike and/or the present gearbox ?
Gentlemen - if we can get back to the original post, please..........!
The point I attempted to make in my response is that any alloy rim will corrode if neglected.
However, I think in the case of DC's bike I would be very disappointed to find that level of corrosion in just 5 years, particularly to a tubeless rim. (My understanding of these is that they should be particularly well-sealed against such deterioration, with the inflation valve the only weakness - or maybe I have that wrong.)
I should point out that the Bulto/Akront tubed rim in my pic. had worn its tyre undisturbed since 30 years ago, (when I bought the bike as a non-runner) and possibly up to 34 years (when the tyre was new) - and of course has many more holes to allow the ingress of moisture than a tubeless ........
You came here seeking advice - which was freely given. Everyone in this free world is entitled to his own opinion. No need to go off the deep end........
(This is from another old man with lots of Bultacos)
Removing the cylinder base sleeve nuts can often prove a task in itself if a p.o. has used an ill-fitting key and rounded-off the internal hexagons - you have
removed all the nuts, haven't you ? (Maybe, not obvious to someone unfamiliar with working on these engines......)
Jarring the barrel with a hammer and piece of wood to the exhaust port, or similar usually then does the trick.
Do not lever on the cooling fins or any joint face !
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1978 bultaco sherpa t
in Bultaco
Posted · Edited by lorenzo
Further supported by the use of top yoke with taper-top stanchions - (on a 198 the top yoke would have 4-bolt split clamp with parallel-top stanchions.)
If the frame is stamped RM198, it probably was - that's an engine number.............
Tank/seat unit is standard Bultaco Slimline/Kit Campeon, which also matches model 91/92 from 1973.
Whatever, frame is an obvious re-stamp.