Author Topic: 80 Plus, kick starter ratchet.  (Read 9233 times)

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Offline KiwiJohn

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80 Plus, kick starter ratchet.
« on: 07 Apr 2005 at 23:53 »
My 80 Plus starter has a problem in that it slips on occasions,  if I try to push from the top of the pedal stroke it almost always slips but if I ease the pedal half way down it usually works OK.

I guess the ratchet teeth have got round shoulders. The question is, can I get this out through the side plate of the gearbox while in the bike or do I have to take everything out of the bike and break the gearbox from the engine?

Thanks

Offline don

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Re: 80 Plus, kick starter ratchet.
« Reply #1 on: 13 Apr 2005 at 02:20 »
kiwi john,
I would be interested in any replies that you get, since I have a similar problem with my MkV.  I do have some clues as to the cause of the slipping.  When I got the bike it had an external stop added to prevent the kickstart arm from reaching vertical.  I assumed that this had been added because the internal stop had been broken.  When I disassembled the gearbox to replace seals, I found that the internal stop was intact, so I assembled the machine with the shaft located so as to rely on the internal stop.  The result was exactly the problem that you have encountered.  Since the ratchet did not slip when the external stop was in use, I have inferred that the fault is that the movable ratchet is not close enough to the one to which it mates until the arm (or the shaft on which it is mounted) is moved through about half of its arc.  I believe that the same effect as lowering the kickstart to half mast can be produced by shimming the movable ratchet nearer to the driven one.  This I intend to do, but I took the bike to our summer place six hundred miles away and may not get it into the shop until next  Fall.  I believe that the gearbox does have to come out to get at the mechanism, but I am not sure about this.  The manual may answer this for us.  I hope this  is of some use.
Don Moor

Offline KiwiJohn

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Re: 80 Plus, kick starter ratchet.
« Reply #2 on: 14 Apr 2005 at 08:55 »
Don

It will be some time before I get a chance to dismantle my gearbox and really it is something I would rather not do unless it is necessary.

I have been studying the manual for clues and to gain of understanding of exactly how it works.

Although I dont exactly understand how the worm sleeve and the pinion move at the start of the pedal stroke I feel that the pinion would be less inclined to move towards engagement if the oil is too thick.  The manual says 50 weight oil.  I might try a thinner oil and see what happens.

Just a thought and something that I can do without major dismantling.

Offline KiwiJohn

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Re: 80 Plus, kick starter ratchet.
« Reply #3 on: 02 Oct 2005 at 20:38 »
My Plus 80 is at the same stage it has been for the last few years,  "almost ready"!  :lol:  Well, there are other things that keep cropping to to demand my time.

I have been aware from the beginning that the kick starter tends to slip when used over the full stroke, so far it seems OK for short strokes over the bottom half of the travel.

I assume the ratchet is (as we say arround here 'rat $hyte') and I am wondering just what I will be up against when it finally fails completely.

Question, can I get the starter gear out without removing the gearbox from the engine or even removing the works from the bike proper?

Thanks

Offline don

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Re: 80 Plus, kick starter ratchet.
« Reply #4 on: 02 Nov 2006 at 21:43 »
This is a belated reply to a query by Kiwi John about a year ago. He noted that his kickstarter slipped a cog if he tried to use it over the full stroke, but engaged properly over a half stroke. I had the same problem with my bike, a Mk V. When I got the bike it did not have the problem. A previous owner had made up an external stop for the kickstart return, so that the internal stop did not come into play. (This is a clue.) Just this week I finally took the mechanism apart to try a remedy. (The answer to John's question whether the mechanism can be dismantled without removing the unit from the frame is Yes, just follow the manual.) I didn't see any noticeable wear or breakage in the ratchet teeth, so I was resolved to just machine a spacer that would bring the ratchet nearer to engagement, so that after the slippage occurred there would be more of the stroke remaining. Fortunately I noticed before I put things back together that the pawl was slightly loose on the worm sleeve for the ratchet pinion. It could be slid about .050" from its "home " position on the worm sleeve. Seeing this enabled me to conceive a plausible explanation for the problem. When the kickstart lever was returned to its home position the pawl hit the stop and the ratchet pinion was driven forcefully against the pawl, thus moving the pawl away from its home position on the worm sleeve. When the kickstart lever was next depressed the ratchet pinion would move easily along the worm into engagement with the ratchet teeth on the bevel pinion. When the ratchets first came into engagement the resistance would cause the ratchet pinion to push against the worm sleeve and move it back into the home position within the pawl. This withdrawal momentarily removed the pressure forcing the ratchets into engagement, and the first tooth was skipped. After the sleeve had been forced back into its proper position in the pawl, the ratchets engaged as they were designed to do. So I reasoned. It seemed to me as if the only way to confirm my theory was to fix the pawl in place on the worm sleeve and try the thing. Upsetting the pawl with a center punch around the perimeter of the serrated portion of the sleeve seemed a possibility, but I elected to silver solder the joint. This I did, and reassembled the device. It worked, and I can now spin the engine with a full stroke. I did also use the .050" spacer that I had made. It fits onto the worm to prevent the ratchet pinion from returning all the way to the pawl. Its outside diameter is 1 3/16", to prevent any possible interference with the kickstarter pinion. The only benefit to this is the quicker engagement of the ratchet.
I would be very pleased to hear of any other members' experience with this sort of problem.

Don Moor

Offline KiwiJohn

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Re: 80 Plus, kick starter ratchet.
« Reply #5 on: 03 Nov 2006 at 00:17 »
Thank you for the information Don.   I will certainly examine it further and hopefully defeat this annoying defect.  Meanwhile I am still waiting on someone to asess my forks!  Such things seem to take weeks and weeks!  At this rate another summer will be gone before I have it on the road again :cry:


John's plea for help in regard to the forks on his Plus 80 can be read here.
Alwyn
« Last Edit: 04 Nov 2006 at 09:53 by alwyn »

Offline aggettd

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Re: 80 Plus, kick starter ratchet.
« Reply #6 on: 20 May 2008 at 14:56 »
Don:

You asked for feedback from members with any experience following on from your advice.

This past winter I obtained a NOS pawl/worm sleeve combo and proceeded to replace the old one. Interestingly, the worm sleeve was not appreciably worn, but the pawl plate was loose on the sleeve, as was your experience. The replacement went very smoothly, but as I was replacing rather than repairing the old part, I assumed (incorrectly) that the .050 inch spacer was not necessary. As it turned out, the new part fixed 90% of the problem, but on very rare occasions I get a bit of slip. I can live with it for now, but if I ever have to dismantle the g'box again, I'll slip in a spacer.

Thanks for the great information/advice. My poor, abused knee appreciates it.

David Aggett