Poor boy vs stator replacement

[kpritchett70]

I've got an 84 1200 interstate with 97000miles and a dead stator leg. I'm trying to decide the best option to repair/upgrade the charging system. I have read many post here and on other forums but they all seem several years old. I have a few questions and any help would be greatly appreciated.



1. Is there anyone here that has a poor boy conversion if so how do you like it for the long term?

2. Is there a source for the crank pulley? Does anyone make a kit if not I am confident I can fabricate the brackets and spacers needed for mounting and do the install.

3. Are the stator repair parts found on the internet any better than the original?

4. To anyone that has replaced the stator have you had any problems in the long term?

I have to do one or the other and just hate the idea of putting a ticking time bomb back in that can go off at any time and leave me stranded. Thanks for the help, recommendations, opinions etc in advance.

[Sassy]

I did a stator replacement long ago and it wasn't a problem for the next severslr years of ownership.
It was a lotta work but it is just RnR bolts and pieces.
Ive never done a Porboy but it is different in that I believe it requires a slightly different skill set due to thd fabrication and problem solving required.
Whatever your decision good luck and post up your
experience.

[Rambozo]

Replace the stator and swap the shunt regulator to a series regulator. Bomb defused. With a series regulator the stator will last forever.

[kpritchett70]

Where can I find a series regulator? And is it a direct replacement?

[Rambozo]

http://roadstercycle.com/Roadstercycle% ... lators.htm
Replacement is pretty straight forward, but they need cool air and often won't fit in the stock location on old Wings. By now most stator wiring is in need of replacement anyway, so no big deal to rewire.

[kpritchett70]

Thanks for the info.

[kpritchett70]

Anyone have and idea how many amps the stator puts out?

[Rambozo]

Anyone have and idea how many amps the stator puts out?

About 25 amps @ 3000 rpm.
Unlike an alternator, with a stator and a shunt regulator, more is not better. You want to match the load as closely as possible with just a little extra to charge the battery.

[the_big_h]

I had my engine out to fix a starter clutch issue, I noticed the OEM stator was slightly damaged so I replaced it with an aftermarket stator.
This aftermarket stator lasted less than 3000 km, providing the incentive to do a poorboy conversion (it's a lot of work to pull that engine!)
My fab skills are fairly high, I managed a really neat installation.
I was a bit disappointed in the results - when cold, it maintained 13.8 volts at 800RPM idle, but when hot it did not. The alternator was not spinning fast enough at idle.
In my installation I used an extra-small pulley on the alternator, and used the largest purchased pulley I could fit on the crankshaft. I used V-belt pulleys, not micro-V. I machined a stub shaft for crankshaft extension, to maintain perfect concentricity for this pulley.
I used 11mm wide belt because I couldn't find 10mm wide belt (I probably just didn't look hard enough). The 10mm belt would have run lower in the alternator pulley, and if I had machined up the crankshaft pulley from scratch I could have made it probably 10% larger diameter (because of the narrower width, especially if custom for 10mm wide belt), I think that would have worked better.

That's my experience.

[Rednaxs60]

I use a 4” pulley on the crank, 2” on the alternator. 14.2 VDC always unless rad fan on. No issues when hot and my alternator is covered.

I do not connect to the battery. I have a power junction that everything connects to and is fed from.

I keep the RPM at 1000 +/- 100. Manual calls for 950 +/- 100

Good Luck

[Rambozo]

I had my engine out to fix a starter clutch issue, I noticed the OEM stator was slightly damaged so I replaced it with an aftermarket stator.
This aftermarket stator lasted less than 3000 km, providing the incentive to do a poorboy conversion (it's a lot of work to pull that engine!)
My fab skills are fairly high, I managed a really neat installation.
I was a bit disappointed in the results - when cold, it maintained 13.8 volts at 800RPM idle, but when hot it did not. The alternator was not spinning fast enough at idle.
In my installation I used an extra-small pulley on the alternator, and used the largest purchased pulley I could fit on the crankshaft. I used V-belt pulleys, not micro-V. I machined a stub shaft for crankshaft extension, to maintain perfect concentricity for this pulley.
I used 11mm wide belt because I couldn't find 10mm wide belt (I probably just didn't look hard enough). The 10mm belt would have run lower in the alternator pulley, and if I had machined up the crankshaft pulley from scratch I could have made it probably 10% larger diameter (because of the narrower width, especially if custom for 10mm wide belt), I think that would have worked better.

That's my experience.

That is the main issue with alternator conversions. There just isn't enough room for the normal drive system. Most alternators need to spin at about 2,400 rpm at idle, have their maximum output above 6,000 rpm, and should never exceed 18,000 rpm. So for your 800 rpm idle you would want a 3:1 drive ratio, but your 8,000 redline would limit you to 2.25:1. Your typical alternator has about a 2" plus V pulley, so that needs a minimum 4.5" crank pulley. A micro-v could shrink them a bit, but the best would probably be a timing belt.

[Ohara]

Did my poor boy conversion on my 86 Aspencade a few years back. I enjoy the peace of mind I have knowing that where ever I go I am Not at the mercy of a stator failure. Either way you go it will require some work, good luck with your project.