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mike@oldnut.co.uk's Achievements



  1. Good luck with it, very difficult to see what is happening as it happens so quickly, I would suggest putting the carboard under the 2nd contact trick first to see what happens, then try without, you really need a slow motion video to see when it starts turning 'vigorously'
  2. CL - Centre line, I should have perhaps said CRS centres between the crankshaft and the starter. The CAV manual 'dictates' that with a cast iron ring gear, the sides of the teeth are sq, with a steel ring gear there is lead, I will have a furkle for the relevant page and paste it in.......goes off furkling! hmmm the chamfer as described above is for 'non axial' starters (A BS5 is an axial starter, what that means is that the whole commutator and the pinion slides sideways to engage the teeth, then it spins up, the problem is that when they go 'wrong' they spin up before they should hence chewing the pinion against the ring gear, a 'non axial is a 'bendix type' ie, the commutator does not slide, it rotates in the same place, the centrifugal force throws the pinion down a spiral thread against a spring which throws it back out of mesh when starter button released.
  3. Well Gentlemen, took my starter to Cannock today to get it refurbed, not sure how long before it comes back, their comment was 'every one of these we get has a chewed up pinion' they were not able to say why! if you looked at my starter there are no obvious reasons, my trip lever looks in good shape, no rounding, the spring is all present and appears correct, now does it have the correct tension, that I do not know, yes the contacts are probably 60% eroded away, but it still worked when it meshed! the solenoid pulls forward with a bit of slop, yes the commutator would benefit from a skim, the rear bearing appears to have no play, the front one has a little play, if i had a vice I could have measured it, well only if I had brought a dti with me! but i do have digital calipers, interestingly for those who can recall it has some shims behind to space out the CL a little, these are actually bits of 1/2" copper pipe beaten flat, measure around 0.065" which coincidently was the rotational clearance betwixt pinion and ring gear, took the shims out and the clearance is now +/-0.036" this does include some of that clearance in the front bearing, so, what is the problem? at this point I could not point the finger at any one thing, presumably a combination, as one also has to presume that all the starters that arrived at CJF arrived with a trashed pinion but left in good working order and they do not know what the problem is, well if they do they were not 'letting on'! BTW using a thin bit of strimmer cord I measured the flywheel, the major diameter is 22.5" the reduced area which is below the crown of the teeth but near the PCD, is 22"
  4. Hi Martin I am off to our boat today, I will be removing the starter and taking it up to CJF 01543424717 in Cannock for either, repair or service exchange, I am convinced it is the second stage contact coming in too early, hence it turns into a milling machine, mine has got worse over a number of years, it cannot be anything to do with the 'engine/flywheel/ring gear' no doubt same as you, so it can only be the starter, I doubt it is the battery, I will know for sure next week when I get it replaced. you can call me if you wish, you will find me on messenger. Rgds Mike
  5. All things are on the table, it will be a couple of weeks before I get back again, anyone got a comment on the correct rotational 'backlash' twixt pinion and ring gear? I am sure I have way to much atm, mr google seems to average out at about 0.030"
  6. It would not surprise me, just spoken to the long time prev owner, who advised the problem occurred occasionally in 2010 getting slowly worse over the years, alternative starter fitted but no better, this starter, the one we have now, went for repair in 07 2017, the boat went up for sale within a year so only doing 390 hrs since the starter check , during the test the clutch and carrier was tested, new drive end bush fitted along with a new pinion and bench tested, now to me a simple 'stick it in the vice and run jobby' would show everything sliding out and spinny stuff happening, but this would not show that clear step between the two phases, that of sliding then spinning, all too quick, now your question is something I have been pondering, is it possible that somehow in the first stage we are somehow getting too much torque, so butting them makes spin, not donk, stop which is what it should do, CAV 'words and music' refer to this, and as I pointed out in response to Tracy was it? if you look at the end of the ring gear what are the odds on hitting tooth or a gap, if not 50/50, certainly 40/60 so you would expect nearly 40% Donk, then enter on the 2nd dab of the starter switch, so, it has to be either a solenoid or as you say, electrickery in the wrong place!
  7. Correct, i originally read it incorrectly as I said, read as in past tense ?
  8. Hi all, i read the cav manual incorrectly, the clearance between the ring gear and pinion at rest should be 0.125" +/- 0.031" I read that as max 0.125" and min 0.031" however the problem does appear to be the 2nd stage triggering way too early, when pushing the armature in by hand the 2nd stage does not trigger until the teeth are fully engaged, it all happens too quickly to see what is happening, the latch looks to be in perfect condition so I need to understand why it is 'tripping' when the teeth butt, when I next go back I will have more time and information on what to check, I am trying to purchase a whole new 12v BBNG solenoid assembly but they are 'hens teeth' atm, when I strted trying to fix the 10 year old problem the gap was +/- 0.125" I did mistakenly move it closer, see above. So my plan is:- remove flywheel cover, check out the flywhhel diameter and no of teeth for the records, probably remove the shims behind to see if it still meshes ok or not(what should the backlash be? I dont yet know) dress up the pinion, reset the gap to 0.125" put cardboard under the second stage and press the button, it should then do one of two things, either butt the teeth, in which case it should just stop with a small donk, release the starter button, press again, during which time as it travels forward and slowly rotates it should slide into mesh, or, it would have gone into mesh first time, if you think about it there are 50% flat teeth on the ring gear and 50% gaps, so you nearly have a 50/50 chance of donk or mesh first time, if not then second time ?
  9. hi, You are thinking the same as me, what happens when the teeth butt, I like you thought it needed enough torque so turn into engagement, that is not apparently what should happen, go to youtube and search 2L2 starting, there are a couple of vids there, what you hear is a bit of a clunk if the teeth butt, you then release the key or in our case button, then press again, as the pinion comes out it turns slowly, so if it hits first time you press, second time it will go into engagement and off you go. My problem is when it butts I then have too much torque (has the second stage engaged too early?, we dont yet know as it all happens too quickly) and it just spins up.
  10. Good morning, I follow what you are saying, however in marine applications on these Axial starters the pinion is generally Bronze, presumably because it is relatively easy to change the pinion not the ring gear. the picture i posted is a nos pinion and yes the chamfer does look a bit odd, the CAV manuals dictate no ring gear chamfer on an Axial starter, but yes on a 'bendix' type. from what I saw yesterday it would appear that if an axial starter comes out and the teeth butt(they come out quite gently)you just release the key and try again, as it slides out it is also slowly rotating so hit first time it should engage 2nd time. The starter I am trying to sort comes out but if it butts it then spins up, if it engages it works fine, there are two contacts, the first starte the axial and slow rotation, the second brings in the full power after about 1" of travel when the tetth are engaged, all this happens pdq so very difficult to see the sequence but it seems like my 2nd stage contact is coming on too early, yet all looks as it should and when pushed manually the 2nd stage trips when it should, so we have a few possibilities to check, bear in mind this starter has been doing this for at least 10 years, hence why the owners gave up and resorted to engaging it manually and chocking it engaged with a bit of dowel, this works 100% but is a pain and you don't stop the engine when you ought to. So there is nothing obviously wrong with it!
  11. Thank you, unfortunately there is a but, it is same or at least similar to the top one, the rub is...in the CAV manual that could be either a BBNG or a BBNFA, the others are type 267 which is certainly not what I have.
  12. I believe it to be a BBNG 12V but it could be a BBNFA, the manual does not describe the difference, but it is either one or the other! I have at the moment no way of telling.
  13. Hi All, I have only ever seen 12 and 13 teeth bronze pinions for the CAV BS5 12V starter, not saying there is not 10 and 11, but I have never seen one, there was a comment above about left or right hand ring gear, this I would understand if there was a chamfer but there is non, and nobody has yet added a reasoned response to the CAV manual statement that 'a cast iron ring gear' has no chamfer, whilst a 'steel one would' I understand that a chamfer on a cast iron one would create a weak point, but a chamfer is either needed or not, now I suppose you might imagine that a cast one is 'more slippy' than a steel one when the teeth butt, however from what I saw on youtube this morning showing a starter 'butting' first try and it just 'stopped' I imagine with the teeth 'butted' releasing the key probably then allowed the pinion to rotate a bit more when the key was turned again allowing it to mesh and then start. My gut feeling is the 2nd stage latch dropping when the teeth butt, we shall see and I will report back! I would drop the pdf manual but it is too large, others have proffered links. I only wish that I could get a new solenoid which comes complete with contacts, latch etc. Regards Mike
  14. Never heard of an 11 tooth, only 12 and 13, thats a new one on me, Melvyn from MPS reckons very little difference between them in diameter 0.1mm, mine meshes fine, when held in there is rotational clearance, my gut feeling is that stage 2 is coming in when the teeth butt, we shall see when I go back, i shall add you observation to the others and work my way through them. rgds Mike
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