40 Amp questions, please help

[Bigin886]

Picked up a used 40 amp the other day, came with all new O-rings in packages, alternator, Base and mounting plate are assembled. I would like to insure it is functional before I tear down bike.
Observations: When I hold mounting plate on base and spin gear assy. there is visually runout showing. When I support both mounting plate and end bearing by nut and have somebody spin gear assy., it spins true. I can not feel a bad bearing, it just seems a little loose. When I attach the alternator to the base, things also seem to tighten up and run true. Alternator is clean but has a little road grim inside on wound coils. I noticed when I turn alternator shaft clockwise looking down on shaft, everything is smooth and quiet. When I turn counterclockwise I get a very small scratch sound from inside unit. Does anybody know which way a 40 amp rotates? The plan is to remove the 28 amp and base and install (new/used) 40 amp and base. Bases should be the same except for mounting plate, at least by all the research I have gathered thru this forum and honda manuals. I am upgrading a Black "91" with 65,000 miles on it.

 

[DeanR]

I'm holding an old 40 amper right now. Shaft spins freely both directions, can't answer which way it turns when operating. Same project coming up for my 91.

 

[dmeriweather]

When I upgraded my 91 ssmst with a 40 amp alternator that I got off a wreck 1998 st miles unknow, I took it down to the checker auto parts store where I had them test it before I install it. Install mine on my bike in 2008 with 86,000 miles still work great David.

 

[Bigin886]

DeanR, Thanks. Looks like you have two ST's in the stable, thats nice. I was worried that the small scratch sound I was hearing as I turned it counterclockwise was from something shorting or stuck in armature. For all I know it is a normal condition. Maybe a mouse is in there from sitting on the shelf with the seller for a year. Might just be dry. I got a great deal, all the wires and fusable link, new oil filter, o-rings for alt and rear wheel, base and alternator. $75.00 + ship, and it was domestic. I am going to try and test it at the auto parts store.

 

[sofawizard]

hi bigin ive just went and checked my 40 amp no scraping noises in any direction so yours has an issue id remove the end cover and look at the carbon bushes make sure there in 1 bit

 

[JPrieST]

hi bigin ive just went and checked my 40 amp no scraping noises in any direction so yours has an issue id remove the end cover and look at the carbon bushes make sure there in 1 bit

:thumbup: check the brushes.

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[Bigin886]

Cool bean, I wll check out those brushes, i do not want down time when I do the upgrade. Thanks

 

[Bigin886]

Update: Just checked out brushes, they appear to be in real good shape. Not oily, no oil around slip rings, Brushes have approx. .200 of life before they hit the ND signia. Slip rings are smooth, no wear steps. Checked Ohm between slip rings at 3.2 ohm. Spun drive with brushes out, no noise at all in either direction. Reassembled everything and still quiet. Maybe the brushes were cocked a little on slip ring. Might still take it down to the alternator shop and have it spun. Thanks

 

[sofawizard]

well today i fitted the new alternator into my pan so no more questions on it i will tell u this its a big job to get in there ive done half the job today ill rebuild the rear end of the pan
tommorow short winter days dont give much time to do the full job in1 go

 

[Fearmor]

well today i fitted the new alternator into my pan so no more questions on it i will tell u this its a big job to get in there ive done half the job today ill rebuild the rear end of the pan
tommorow short winter days dont give much time to do the full job in1 go

I,m about to replace the altenator in my 96 pan.While I,m at it I,ll powder coat the swing arm and change the timing belt.there,s 76K miles on it so T belt is nearly due for renewal.When its completed its for sale(I have another lower milage pan).Like most of the altenator trouble this side of the pond the casing on mine is cracked due to grim off the road.Is there any way of stopping this happening again.

sofawizard,,where did you source your altenator?? Dave Silver is 525 pounds stirling + shipping to Ireland !!!

 

[sofawizard]

i got mine off ebay germany second hand but very nearly new going on the condition of it ?164 to my door very happy was gona do a canibal job with an alternator out a goldwing or kubota digger there about the corect size when i found this little belter hiding on ebay germany

 

[Fearmor]

i got mine off ebay germany second hand but very nearly new going on the condition of it ?164 to my door very happy was gona do a canibal job with an alternator out a goldwing or kubota digger there about the corect size when i found this little belter hiding on ebay germany

Thanks,I,ll keep a look out for one,didn,t start to strip the bike yet so i,m not in a big rush

 

[JPrieST]

Like most of the altenator trouble this side of the pond the casing on mine is cracked due to grim off the road.Is there any way of stopping this happening again. !!!

Fearmor, have you thought about making a home made extension for the FRONT side of your REAR fender? I just came across a thread about this recently and plan to do this myself soon. The last time I had my fuel tank out I was looking around and found a number of small pieces of gravel in and around the alternator. (I have an 80 meter gravel drive way to my house) I had to use needle nose pliers and dig some pieces out. I've been wondering about a solution myself. Don't know if it would help or not as I would think the gas tank would stop debris from the rear wheel getting that far forward.

I'll look at it this weekend as I will have the tank and carbs out then. I recently made and installed a belly pan also, don't know if that will help, but hope so.

 

[Critters]

Fearmor, have you thought about making a home made extension for the FRONT side of your REAR fender?

Would this help solve your problem??

http://www.st1300-accessories.co.uk/st1100_shock_protect.html

 

[JPrieST]

Would this help solve your problem??

http://www.st1300-accessories.co.uk/st1100_shock_protect.html

I'm hoping it will in my case. I plan to make one out of an old automotive rubber floor mat as others here have done. The thread I read discussing this did not specifically say it would help keep debris out of the alternator though, so will see.

 

[Fearmor]

Joel and Brian,,I was thinking along them lines myself and maybe some kind of a belly pan as well.I have one concern,as the 40 amp unit is aircooled as opposed to the oil cooled unit in the earlier,if the air flow is restricted too much will the altenator overheat?
Pat

 

[JPrieST]

Joel and Brian,,I was thinking along them lines myself and maybe some kind of a belly pan as well.I have one concern,as the 40 amp unit is aircooled as opposed to the oil cooled unit in the earlier,if the air flow is restricted too much will the altenator overheat?
Pat

My thought is if there is enough air flow to keep the engine in operating range (temp) it should be enough to keep the alternator from over heating. Good point to keep in mind though, as I *think* I feel a bit more warmth at my left knee since installing the belly pan. Engine still running in same range though.


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[sofawizard]

alternator requires air to cool the windings these can warm upo far faster than the engine and wont be cooled by the cooling system i think im gona buy 1 of these gaurd extender thingys tho to protect the swingarm as ive just spent time and money cleaning it up rusts not to bad for 71k but id like it to last a few more years

 

[Bigin886]

Hey Fearmor, Found it in Colorado, I just kept searching random strings on the internet and found some ST Gold. Just had all the inside components checked at an authorized Denso shop. Got the thumbs up. I made my Swingarm wrench from a 1-1/8 socket and some scrap steel I found in the shop. I also lucked out and made a Lewis pin from the posted instructions on this forum, used a 6mm carbide drill shank, cut off at 9/16" and burnt an .080 hole thru it for a cable. Cant wait to tear into bike, right now it is 15 degrees outside, so I will be waiting a while. Sounds like Sofawizard is well into his project. I like your idea to powdercoat swingarm, are you going to spray it and bake it yourself? It can be done, I have a friend that does his powder coating in his garage in an old range. Just have to crank the heat up a while.

 

[DeanR]

Just had all the inside components checked at an authorized Denso shop. Got the thumbs up.

How did you find Denso authorized shops? I can't seem to find any listing.