Picking up my new-to-me ST1100 later today... its a 91, with 63k miles... would it be a wise thing to upgrade the alt BEFORE its a problem... or just ride the way it is... ? Whats the biggest problem for the OEM units... time or miles? or both ?
Newbie question... upgrade alt BEFORE its a problem?
- Thread starter Jay B RDH
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From the research I've done (considering that I'm a new owner of a '91 as well), if you don't use a lot of accessories, it's fine. In my case the most I'll run is a cell phone charger, so I don't have any plans to replace it. Granted, if prior owners were running heated gear, electronics, extra lights... your mileage may vary.
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Mostly load.
When you get it put a piece of white paper on the floor under the alternator overnight. Check in the morning for signs of leakage. If dry you have a bit of time, if damp it’s a sooner than later proposition.
Check the condition of the red connector attached to the main relay. Also check the connector to the voltage regulator rectifier.
If they are in good condition you will have some time.
When you get it put a piece of white paper on the floor under the alternator overnight. Check in the morning for signs of leakage. If dry you have a bit of time, if damp it’s a sooner than later proposition.
Check the condition of the red connector attached to the main relay. Also check the connector to the voltage regulator rectifier.
If they are in good condition you will have some time.
TBH, no one knows for sure, but I expect it's both time and miles, coupled with the environment it's in and the overall load it sees. Like any fatigue issue, it's complicated. If it's your primary source of transportation or if you tour a lot, a preventative upgrade to the 40A would probably be worth it, especially if you plan to keep the bike. If it's just a run-around town bike, I'd leave as is and only replace when if it fails. See this thread, or search eBay for "Honda ST1100 40 amp upgrade" to get the upgrade kit. Note that you'll also need the 40A alternator itself, which can be found on eBay.
OP
OP
Thanks guys... Paul, I looked at the upgrade kit/and alt... am considering it for a project for this coming fall after i put it away for the season... also planning on some other changes/upgrades..
Mine's a '94. I bought it with 17,000 miles and it has 36,000 miles on it now. I upgraded my alternator last year. It was still working fine, but it had started to leak. The old 29 ampers are oil bathed. Good idea, but over time, and think about it, my bike is 27 years old, the big o-ring that seals the alternator to the housing goes hard and they'll start to leak. The research I did indicated that then they start to leak, they soon go out. So I replaced mine.
I guess if it's still making juice and not leaking I'd probably run it unless you just want to do it. One thing the up grade does for you is to get rid of the external voltage regulator and the associated wiring and plugs that get hot and fry on these things. Being a new owner, whether you decide to upgrade it or not, you'll want to check out those plugs as they are all bad.
The write up on how my upgrade went is in the alternator portion of the forums. There is a terrific loaner kit that has everything you'll need, with instructions on how to do the upgrade.
I got my 40 amp alternator on line. I think I actually got it through Walmart! LOL. The hardest thing for me was finding the 40 amp base plate as the Honda plates are not available ANYWHERE ANYMORE except for salvage yards, but there is a fellow on the forums here who is now selling new plates that he has had made. I believe he sells them through ebay.
My write up is here:
www.st-owners.com
I guess if it's still making juice and not leaking I'd probably run it unless you just want to do it. One thing the up grade does for you is to get rid of the external voltage regulator and the associated wiring and plugs that get hot and fry on these things. Being a new owner, whether you decide to upgrade it or not, you'll want to check out those plugs as they are all bad.
The write up on how my upgrade went is in the alternator portion of the forums. There is a terrific loaner kit that has everything you'll need, with instructions on how to do the upgrade.
I got my 40 amp alternator on line. I think I actually got it through Walmart! LOL. The hardest thing for me was finding the 40 amp base plate as the Honda plates are not available ANYWHERE ANYMORE except for salvage yards, but there is a fellow on the forums here who is now selling new plates that he has had made. I believe he sells them through ebay.
My write up is here:
'94 ST1100 40 amp alternator upgrade completed..Woo Hoo! | ST1100-Alternator
I started this upgrade a little over three months ago when I realized the 28 amp alternator on my '94 was leaking. Honestly, the hardest part was finding an Adapter base plate. You cannot buy them new anymore. A hundred or so phone calls and e-mails later, I found the whole shebang, a used...
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Without and with other parts:
Honda p/n 11202-MAJ-G20 adaptor plate for 40amp upgrade | eBay
Find many great new & used options and get the best deals for Honda p/n 11202-MAJ-G20 adaptor plate for 40amp upgrade at the best online prices at eBay! Free shipping for many products!
www.ebay.com
Honda st1100 40 amp upgrade parts. no alternator 11202-maj-g20 | eBay
Honda st1100 40 amp upgrade parts. Condition is "New". for lining up gear.
www.ebay.com
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Change all of your lights to LEDs. Markers, turn signals, brakes, tail, headlights. You could reduce power consumption by more than 70 watts.
Instead of the F2 which is 36 watts look for an H4 bulb that uses ~15 watts. It would be still twice as bright as the current halogens that you have at one third the power consumption.....
Instead of the F2 which is 36 watts look for an H4 bulb that uses ~15 watts. It would be still twice as bright as the current halogens that you have at one third the power consumption.....
The most frequent problems, I do read every post on this site, as well as archives, are....leakage where the wires exit the housing. This is difficult to impossible to fix.
Second is the wiring....connectors are mechanical and subject to corrosion, loose connections within the connectors and overheat/arcing....all of which can short the alternator.
Overloading with accessories has already been mentioned.
I remove the left side panel and inspect the wiring, connectors and fuses for condition several times a year. Mine is a 1991, but with almost 21,000 miles (PO had himself a 20 year parked garage queen and I had other bikes to ride until recently).
I got dumb-lucky and found a 28 amp unit from a wreck with just a bit over 5000 miles on it....and the wrecker had stored it inside one of his buildings and not outside, belly up. Bought some new o-rings and placed it in my hope-to-never-need part stash. This was six years ago this past August and I haven't seen another in serviceable condition anywhere.
Safe bet these days is to put together a 40 amp replacement stash.
Second is the wiring....connectors are mechanical and subject to corrosion, loose connections within the connectors and overheat/arcing....all of which can short the alternator.
Overloading with accessories has already been mentioned.
I remove the left side panel and inspect the wiring, connectors and fuses for condition several times a year. Mine is a 1991, but with almost 21,000 miles (PO had himself a 20 year parked garage queen and I had other bikes to ride until recently).
I got dumb-lucky and found a 28 amp unit from a wreck with just a bit over 5000 miles on it....and the wrecker had stored it inside one of his buildings and not outside, belly up. Bought some new o-rings and placed it in my hope-to-never-need part stash. This was six years ago this past August and I haven't seen another in serviceable condition anywhere.
Safe bet these days is to put together a 40 amp replacement stash.