Kick start gear not aligning - ideas?

[Swarfcut]

Jules, If you are sure it is a flat top pinion, a flat topped quadrant from an early plunger box should fit. A "one piece flat top " should do, finding the flat top pinion is the hard part.....no problem for you.


   1947/53  Ratchet 67 3167         Pinion  67 3168            Bush  67 3169

           Quadrant  67 3178      Plunger Box, "Flat Top" Quadrant

   1954/57   Ratchet 67 3167        Pinion  67 3376            Bush  67 3169

           Quadrant  42 3160    S/A and Plunger Box "Pointy Top" Quadrant

  Data taken from published parts lists. Both boxes use a common kickstart assembly from S/A introduction.

 On the face of it, for these model years the cylindrical pinion bush and ratchet remain the same,  changes confined to quadrant and pinion tooth form.

 The early longstroke box has a flat top quadrant and pinion, so by my reckoning any flat topped quadrant from any year pre-54 should match your flat tooth pinion. Part numbers change to accommodate minor variations in quadrant construction, splined or plain shafts, but the essential dimensions and fit are the same. As the flat top form was only run for a few years, this may explain the apparent surplus of quadrants and shortage of pinions. As long as pinion and quadrant tooth form match as a pair, they will fit. A pointy tooth quadrant matches a V root pinion, flat top quadrant matches flat root pinion.

 Swarfy.



   

[Jules]

ok Swarfy, appreciate you taking the time for me  , but you have me thinking now about "pointy" vs "flat top" and I thought I'd mastered it! The new pinion (from C&D yonks ago) says it 67 -3376 on the bag, but it looks like its got a flat top on the teeth!! is the difference subtle or obvious, any body have a pic of each??
and "pointy" is correct for s/a, hmm....I think I'd better get a new rachet too then because it doesn't seem to match the new pinion very well, plus a new bush, I cant understand why the bush doesn't just slip out its clearly worn, hence my question about how tight to do up the mainshaft…. cheers

[berger]

same here jules with the flat bits, I went through mine the other day and noticed removable ones and fixed ones , also pointy bits and flat bits. the flat bits being in the bottom of the ratchets and the tops of the quadrants , and the pointy bits in the bottom of the ratchets and top of the quadrants

[Swarfcut]

 Yes, 67  3376 is the later pinion so should have V shaped tooth roots to match a pointy tooth quadrant. So in fact yours is not, as I thought, a rarer earlier pinion with the flat roots. Sorry, just barked up the wrong tree, and an unworn pointy quadrant should do the job. Suppose it hinges on a mis- understanding in the description of what's flat or pointy.

 bergs nailed it better than me, but that's the answer.

 Swarfy.

[Jules]

thanks Berger/Swarfy, things are getting clearer by the minute and I think a picture is worth a thousand words, so here's a few pics showing the meshing of the old bits with new pinion - are they "pointy" or "flat head"?
I'm thinking there might be a bit more life in the old pinion and quadrant yet, maybe?
I'm concerned about the meshing of the old ratchet with the new pinion (doesn't look so well meshed as the old parts)?
I'm concerned about the meshing of the old quadrant with the new pinion (maybe jamming potential)?
I'm planning on a new bush which should certainly help with meshing stability, the old one is well worn/barreled actually, hence my question about overtightening ie what is tight?
No more questions, thanks for your help with this, cheers

[Swarfcut]

Jules Just pulled the cover off an early Plunger box, kickstart return spring is flat clockspring type. Quadrant design has splined shaft, pressed on quadrant with flat top teeth.

 Pinion has 17 teeth, with distinct flat area between the teeth roots. Ratchet teeth mesh fully. 

 Your new pinion looks to be a worse match than the original parts! The teeth have a more straight sided profile, maybe flat roots. It looks almost right for my early type quadrant. C & D  miss pick?

 My pinion has worn quadrant teeth, but the ratchet teeth mesh to the roots, less a bit of wear, your new pinion looks almost pre-worn.


 Swarfy

[Swarfcut]

 Additional   Few more pix. Plunger box, early type. Features a  Quadrant with flat top teeth, splined shaft, pressed on quadrant, clock spring return, anchor peg (not nut and bolt) retains the spring. Outer cover has no grease nipple on clutch arm spindle

 On this box, Mainshaft nut looks a bit suspect, hanging on by a thread. Pinion badly worn and  ratchet spring support washer between pinion sleeve and bearing is missing.

   What other mishaps shall we find inside? Nice bit of sediment there, but no nasty noises or metallic bits in the oil, so looks a good 'un. Thinking about the bearing, an open type here must catch a fair amount of material worn from the ratchet pinion.

 Swarfy

[Jules]

Hi Swarfy, yep definitely looks like the new pinion is flat topped/bottomed, more suitable match for your quadrant in pic vs my quadrant which looks more pointy with the bottom of the pinion less flat too  , but the mismatched ratchet shape is a worry, it looks like they missed the back relief/chamfer to allow the ratchet to slide further in  , maybe fixable with a small grinder if I get desparate….

[Swarfcut]

Jules, your pinion looks like this one as regards ratchet teeth. Maybe a case of mistaken identity at C & D.


https://www.ebay.co.uk/itm/NEW-BSA-M20-M21-B31-B33-RIGID-PLUNGER-KICKSTART-PINION-66-3080-1938-62/143257291483?_trkparms=aid%3D1110006%26algo%3DHOMESPLICE.SIM%26ao%3D1%26asc%3D20200513093106%26meid%3Deda32ddc550642feb8b06131271e9257%26pid%3D100005%26rk%3D5%26rkt%3D12%26mehot%3Dlo%26sd%3D322577000971%26itm%3D143257291483%26pmt%3D1%26noa%3D0%26pg%3D2047675%26algv%3DSimplAMLv5PairwiseWebWithBBEV1Filter%26brand%3DBSA&_trksid=p2047675.c100005.m1851

  Despite appearances, this parts inventory is mainly Indian.  A,B,M Series gearboxes share common design concepts, but there are detail differences.  Draganfly's online parts catalogue offers hours of free entertainment!

 Swarfy.

[Jules]

yep, I think you could be right Swarfy , I'll hold off anything further until I get the new bits from Mike, then see if I can make a silk purse out of a sows ear ! cheers