Starter motor improvement

[jhovel]

Finally, after 27 years of starter motors struggling to turn over strongly enough in the 650s and some 500s, Hann finally diagnosed the real cause of this weakness: a poorly designed ground connection.
Read all about his discovery and proposed solution here:
http://australiancx.asn.au/forum/index.php?topic=4438.msg36529#msg36529

Since I wanted to improve the function of my CX650 starter too, I had a closer look at the insides of mine:

Here, the results of arcing and subsequent corrosion were clearly visible on the three tangs and contact points on the aluminium end cap (yellow squiggles).
I then contemplated if the offending ground connection from the carbon brush couldn't be screwed DIRECTLY to the end cap (which has the ground cable from the battery directly connected to one of it's mounting bolts).
The blue arrow shows the origin and potential connection position.

Not much to loose, I marked the centreline of the cable lug - midway between the carbon brush holder and the original connection post - on the outside of the stator case and measured the centre height of the screw hole from the edge. I then replaced the end cap and transferred the mark to the edge of the end cap.

This centreline is then transferred to the inside of the casting and the 11mm centre height marked and centre-punched. A 2.5mm diameter hole was drilled at as steep an angle as was possible, and the hole tapped with M3 - the same thread size as the original mounting post.

The conductor lug could now be screwed to the inside of the end cap directly with the original screw, with the lug in the position shown, so that it fits between the brush holder and the connector post as planned.

Carefully tilting the end cap over the end plate, lining up the locator groove with the bent-up tang and manipulating the conductor wires into a neat loop that doesn't get caught on anything sounds more difficult than it actually is.


While I was pleased with the result and had all the tools out already, I converted two more starter motors which all showed the same arcing and corrosion patterns that Hann had identified.
All three of them run significantly stronger than before!

Either of these solutions - Hann's or mine - will make a marked improvement to both CX500 and CX650 types in the long run and take less than an hour to do.

[Arty]

Good work Joe

[Glen]

The other thing I have recently learned is that a starter clutch is under far more strain if the starter turns too slowly.
(More likely to wear out by slipping etc)
Top work Sir Joe!

[Rayman]

also - if the starter motor is running slower - you are much more likely to have it fire and develop peak pressure while still on the compression stroke - hammering the starter clutch and stalling the starter motor -
more so with the 650s but possible with the 500s too.

Rayman

[jhovel]

Ray and Glen, this is the bit that worried me most, actually: my starter motor ran beautifully for a few days after I put the engine back together with a perfectly good starter gear and new springs and rollers. Then after a couple of weeks it had it's first 'backfire/starter hammer'. The happened a few more times after that - only occasionally mind you - but there are distinct marks in the starter gear already, after 2200kms in this engine.....
I'm hoping that this mod will stop these altogether. Hann's YouTube video seems to indicate that it should.
I'll report at the VJMC meeting and here every few weeks.

[cxichy]

Finally, it seems like we have some real progress on the starter issues.  Thanks to Joe for another neat solution, but particularly to Hann for pointing out the probable root cause and the first solution.

[ACE]

Well done, Joe...photos are once again sensational too...
ACE

[Arrne]

Great idea! 
Would it be easier/better to drill and tap from the outside?  You could always seal the hole afterwards.

[Onetrack]

There you are ACE . Where you been?

"Young" Les F

[jhovel]

@ Arne:
I had considered drilling and tapping from the outside, but it is a steep angle. You would have to be careful. I also didn't initially want the mod to be visible (I drilled a blind hole). Now that I see where it is on the bike, I see that it wouldn't be visible anyway.
As you say, you could easily plug the hole on the outside once done.

[Onetrack]

Thanks Joe

Done the mod, was going to fit the starter tomorrow but the excitement was too much, fitted it this evening in the dark (I don't do work after dark) and the starter action is much improved.  Will see how it goes over the next few weeks.  Durring the mod noticed that I could do with new brushes, are they available as a standard automotive part?  Although my CX650 starts readily enough the starter motor has at times been reluctant to get up to speed for almost its entire life something I suspect did not happen in Honda's development lab and hopefully now is up to the expected Honda standard.  Thanks again Joe and Hann.

Les F

[ACE]

G'day Les...thanks for asking but after coming back from the recent hols, I have been up to my neck in work...ahh the life of a rural school principal eh? One minute dealing with the builders and architects, the next fishing a dunny roll from the bowl when one of the little tikes thought it would be funny to drop them in...
Still..someone has to keep paying those taxes to keep you old "650 pensioners" living the high life eh! (I can only afford a 500, but just you wait till I retire!)
(and then the fight started )
ACE

[Arty]

ACE,
Can I hear you, please do not tell me you would get cx650 when you retire,how would you explain it to the other 500 purists
Arty

[gavfox]

itll probably be along the lines of he finally feels confident of handeling the power and speed of a 650

[ACE]

Hardy ha ha ha you lot! Actually, I would like to do a "Coops" and bring in a 500 or 650 Turbo from O/S...if i could convince S.W.M.B.O... ...but you are right Gav...I am NOT a great rider having started on road bikes too late in life and I am certainly not a "natural" when it comes to riding techniques...still..the 500 is well and truly great fun for me at a reasonable cost etc...so I will continue in my Grand Poobah Role!
ACE

[Onetrack]

Now another CX650 Turbo - that would be something added to the fleet.  Go for it.

"Young" Les F ( a 650 pensioner)


"650 Pensioner" makes me wounder just how many there are?

[phantomcxmenance]

ace,

by the time we retire mate all the 650 's will be tuck up in one of the "sea changers" come "baby boomers" garages gathering dust,waiting for the prices to increase so that they can cash it all in and buy a harley.so we will just need to keep our ultra relaible 500's going and keep on riding man

[Onetrack]

Phanto

At least we can use them 7 days a week and when the post baby boomers finally realise what they missed and want one hopefully they will offer a good price for something worn out from frequent use.  I won't be spending the money on a Hardly Ridable.

"Young" Les F (650 pensioner)

[Arrne]

@ Arne:
I had considered drilling and tapping from the outside, but it is a steep angle. You would have to be careful. I also didn't initially want the mod to be visible (I drilled a blind hole). Now that I see where it is on the bike, I see that it wouldn't be visible anyway.
As you say, you could easily plug the hole on the outside once done.

  Just a thought.

[cxichy]

I've decided to do this excellent mod to my starter motor before I head off for the VJMC.

After I get the starter open, I will check the brushes.  What is the best source of replacement brushes?

Also, I've checked this site, the RDavis site and Hann's site  but can't find a "starter motor refurbishment" guide.  Can anyone point me to one?

Thanks

Alan

[Onetrack]

CXichy

Took me about 45 min to do.  I used a cable strap made from 240 volt flex cable (both strands) as this cable is very flexible and well insulated.  It may not be a good idea to get carried away and clean up the commutator and other parts too much other than use a gentle solvent like metho and a soft rubber like an eraser on the commutator.  The strap I fitted went from the brush terminal to the end cap.  I figured this would make reassembly easier.  The strap is about 35 mm long with lugs, just the right length to fit without any folds.  I definitely recommend this mod what ever method you use.

Les F

[cxichy]

Thanks Les.  Sounds like you have used a third variant.  Hann used a rigid strap between the base plate and cover, Joe terminated the existing brush wire on to the cover, and seems like you used Hann's method but with a flexible strap to the brush terminal?  And in your case, unlike Hann's, the nut doesn't need to be soldered in place because the cover can be removed without disconnecting the strap?

And by 240V flex cable, do you mean the sort of wiring that is used on irons and 2400W bar heaters (with the cloth outer insulator?).  I guess the length is so short that it doesn't need to be too high capacity?

Now, I'll find my camera and make a "before" recording.  Might be a couple of days before I can get to do the job, and post a recording of "after".

[jhovel]

@cxichy:
Have a look here:
http://australiancx.asn.au/forum/index.php?topic=702.msg3792#msg3792

[Onetrack]

CXichy

The cable I used is the type that you see on a table lamp or other some other small appliance - 240volt 2 core flex -this cable is rated at 7.5 amp with very fine multiple strands and using the two conductors in parallel theoretically gives 15 amp rating.  The load of the starter motor could be up to 50 amps but the strap is not taking all the load and is of short distance and short time duration.  The twin conductors are just a bit less than the diameter of the cable on the brush which does take all the load.  Hanns method is good but needs some accuracy and I did not have a suitable piece of steel or copper to make one like his so I used a piece of cable.  The cable is fitted to the brush terminal and then bolted to the cover before assembly, only one hole needs to be drilled and the brush plate does not need to be disturbed.
 

I can't believe it took 27 years to discover such a simple fault so easily repaired with such marvelous results, thanks again Hanns and Joe, now if I could fix a wobble........

Les F

[TasEric]

Thanks for the great detective work, and ingenious solution.

cheers,
Eric G.