40A Alternator Help

Joined
May 2, 2010
Messages
82
Location
Co Durham, UK
Bike
ST1100AX
After fitting the replacement engine in my ST1100, I have found the voltage regulator in the alternator that was attached to the replacement engine is faulty letting the output from it to go to 16V and above when you increase the revs.

Is it possible to take the back cover off the alternator and change the regulator without removing the swingarm, can you get to it just by removing the fuel tank?

Thanks
Keith
 
Is it possible to take the back cover off the alternator and change the regulator without removing the swingarm, can you get to it just by removing the fuel tank?


There are folks on this site who should be able to answer your question directly. If not, go to the following site. It has a wealth of information on the ST1100 in general and quite a bit on the alternator in particular:

http://www.stocrallies.com/st-riders/index.php?board=3.0
 
I've done the 40 amp upgrade and I examined this at the time. I *think* that you can get the regulator/rectifier off, but it will be tight.

Either way, you will have to take the tank out and I would plan on pulling the rear wheel and inner fender, too; just to make things easier.

Maybe George or John Oo will chime in....
 
Yeah I'd say you should be able to -not a lot of room behind it, but I was able to take the undo the bolts and let the generator rock from side to side.

Do you have a spare 40 amp generator? Even if it's faulty, I might be interested -I have a cracked casing on mine. I'm going to try welding first, but I'm not sure how succesful it will be.
 
Took the tank out last night and decided to take the swingarm off to get to it, so stripped the rear wheel, etc ready to do that tonight.
My dad in on making a tool to get the swingarm locknut off.
Once the swingarm is off I might as well clean it up properly (take the dust off) and hamarite it all.

Fran, the alternator that the regulator is faulty on is the one on the replacement engine from Paul (Alphafang on here).
I will be using the regulator from my engine to put on this alternator.
Once all complete and tested the engine I took out will be going back to Paul.

If you contact Paul (Alphafang) if you cannot weld your alternator casing I am sure you can come to an arrangement with him, if he has the engine back by then you can arrange delivery with him, if I still have it I can send the alternator to you (minus the regulator), send him a PM and I will do the same to let him know.
 
Cool I'll see how I go on.

I didn't need the special tool to get the swingarm out, but I will need something to re-torque it (apparently, anyway) when it all goes back.

Good luck with the swingarm -I found 4 holes in mine, so thats on the welding list too! I've cut all the plates for it, just need to get it and the alternator body welded. I'll be adding some waxoil to the swingarm before it's all done too.
 
Swing arm is now off and as I know the alternator on my original engine was working OK I have swapped the whole alternator rather than just the regulator, its a lot easier doing the one on the engine out of the bike than in the frame.

The swing arm looks in good nick so wire brushed it and will hamarite it all now I can get to the bits I could not get to before.

Will also have to pull the carbs again as it looks like I have a coolant leak in the V, hopefully just a hose clamp need doing up properly, after not showing up on a preasure test. :(
 
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