1979 GS550 replacing stator and R/R

[Guest]

Hi everyone!

I just picked up a 1979 GS550 as my first bike and couldn't be more excited! She runs great but isn't recharging while running. I did some poking around and things seem to be pointing to the rectifier or regulator (which are separate things on the 1979 and earlier models). But since I read that a damaged R/R can cause damage to the stator, I want to replace it while I have the oil drained and the side-cover off. Also, it looks like someone wrapped something around one of the coils to fix it previously, so I'm a bit wary of it as is. So basically I want to install new charging components and wiring to future-proof the electrical system as much as possible, but I have a few questions:

1. What kind of stator do I need to buy to make sure it's compatible? Mine has 18 coils but I don't know if it's the original stator, so what other factors should I look for when choosing a replacement? Are there some that last longer than others or are more efficient?
2. Can I replace the separate rectifier and regulator components with a single R/R instead? I've read that a series R/R is recommended, can my bike take one of those? If so, what kind would be compatible with my bike?
3. Is it possible to replace the stator without taking the carburetors off? The alternator wire bundle seems to snake past the compartment with the starter motor and I can't quite reach one of the screws to take that top-cover off.

Thanks in advance for any help and pardon any ignorance on my end! This is my first time around an engine so I'm trying to learn as much as I can but having trouble finding much about my specific bike, so I'm not sure what is applicable and what isn't.

Thanks so much,
phasal

1979 GS550

[aclaytonb]

Everyone here raves about the series (SH775?) polaris r/r but I was cheap and bought a used one from on old Honda (SH232?) for $10. Seems to work with no other mods. Found the list of compatible units in bwringers electrical guide.

18 pole stator sounds right - at least, thats what Rick's has on his site. Hoping I won't have to replace mine any time soon. I would avoid any of the cheap chinese ones and probably wouldn't roll the dice on anything preowned.

I got the cover off of the starter once without pulling the carbs but it was slow and cost me a fair bit of skin. It gets a "little" bit easier if you put in allen head screws but still not really worth it.

Wrapped something around the coils? Like they split and some added duct tape or that "as seen on tv" fiber tape?

[Steve]

Not so sure about your combination of a '79 550 and an 18-pole stator.

Does your bike have a kick starter?

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[phasal]

Not so sure about your combination of a '79 550 and an 18-pole stator.

Does your bike have a kick starter?

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Yeah, it has a kick starter and electric, the previous owner replaced the points with an electric ignition. However, the electric start isn't working right now which might be the starter itself (?) as I can hear a click when I press the button but nothing tries to turn. It kick-starts no problem as long as the battery is charged so it's wasn't as high on my priority list of things to fix.

[tom203]

It sounds like your bike has the 12 pole stator/ rotor setup. Most rics seem to be for the 18 pole setup, so beware. The series sh-775 is the way to go for reliability, but the honda shunts like the sh-232 are fine till you get your electrical system sorted out.

[Steve]

Not so sure about your combination of a '79 550 and an 18-pole stator.

Does your bike have a kick starter?

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Yeah, it has a kick starter and electric, ...

Interesting.

May sound a bit silly, but what was the assembly date listed on the VIN plate? According to the parts fiche, when your bike left the factory it had a 12-pole stator. However, there is a possibility if it was one of the last '79s built, they might have started using the 18-pole stators that came on the '80 units.

When you say you "have the side cover off", which side cover are you talking about? Most of the time, when we refer to "side cover", we are talking about the frame cover that is over the battery/fusebox/starter solenoid area just under the seat. Do you mean that you have the stator cover off the engine?

It is possible that a previous owner has installed an 18-pole stator out of ignorance, not knowing they are not compatible in a 12-pole system. They <can> be installed, but you also have to change the rotor. Use a small screwdriver, run it around the inside edge of the stator, count how many times it is attracted to the stator, let us know what you find.

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[aclaytonb]

That's probably a better technique than my searching '79 stators on eBay.

[Steve]

In my playing around with stators over the years, I have found that GSes with a kick starter had 12-pole stators and GSes without a kicker had 18s. There were no kick starters after the '79 model year. However, Suzuki was rather good at blurring the lines between model years. If they ran out of '79 parts and had '80 parts available, they might have started using the '80 parts on the last of the '79s.

Before you go guessing and shopping for something that might not work, please consider a piece of advice in Nessim's signature:
To measure is to know.

In this case, that means you need to actually check how many magnetic poles there are in your rotor to see which stator would be compatible. If you have a rotor for a 12-pole stator and a PO (previous owner) blindly installed an 18-pole stator, there will be NO charging happening, as the two are not interchangable. On the other hand, if all the PO could find was an 18-pole stator and also changed the rotor, there should be no problem.

Count the magnetic poles and report back. Was also not quite sure that you have actually observed that you have an 18-pole stator.

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[phasal]

Count the magnetic poles and report back. Was also not quite sure that you have actually observed that you have an 18-pole stator.
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Man, I am so grateful for everyone's replies on here and especially for all that valuable information, Steve! Sorry for the confusion earlier, when I said "side cover" I was referring to the stator cover of the actual engine. I have actually observed the 18 pole stator in there and included some pictures below.

I couldn't find an assembly date anywhere but I checked the rotor as you described and sure enough, there are 12 magnetic poles in the magnets! Three magnets in the rotor, each with 4 individual magnetic poles! You can even see them clearly in the picture I took.

Stator: https://i.imgur.com/kSW7oOa.jpg
Rotor: https://i.imgur.com/nA0MSBR.jpg

Funny enough, I just noticed when uploading the pictures that there are indented lines inside the stator cover (pictured behind the stator) dividing the area into 12 sections! The PO definitely put the wrong stator in it. I'll definitely be replacing that first, which means the regulator and rectifier might be fine after all.

That being said, do you guys have any recommendations on some of the better places to order parts from? I take it buying a new 12 pole stator would be ideal.

Also, Steve, when you referred to the "parts fiche", is that something available online or do you have an actual microfiche archive from Suzuki? Either way, that sounds like a useful resource

Thanks, everyone! It feels rewarding to have figured at least one thing out and I'm enjoying learning more about my bike!

[tom203]

Lucky you... You have the correct rotor for the 18 pole stator. It has 6 pairs of N/S magnets...or 12 seperate places where Steve's screwdriver will grab as you move it around rotor insides.
Now determine if you have a seperate rectifier and regulator or has that been upgraded to the combo unit.

[phasal]

Lucky you... You have the correct rotor for the 18 pole stator. It has 6 pairs of N/S magnets...or 12 seperate places where Steve's screwdriver will grab as you move it around rotor insides.
Now determine if you have a seperate rectifier and regulator or has that been upgraded to the combo unit.

I'm confused, so you're saying 12 poles on the rotor is meant to pair with an 18 pole stator?

[tom203]

Don't feel bad...google 3 phase power to get more confused! Being a three phase generator, your stator is made up of 3 seperate phases each occuping 6 poles/ slots. The rotor's magnets span these slots...6 pairs of N/S magnets fly by the stator windings producing electricity in a 3 phase sequence.

if you had a 12 pole stator, you would need a matching rotor that had 4 pairs of n/s magnets. Here's a pic of a 12 pole stator

image.jpg

[cowboyup3371]

Also, Steve, when you referred to the "parts fiche", is that something available online or do you have an actual microfiche archive from Suzuki? Either way, that sounds like a useful resource

Any of the motorcycle dealerships will have a link to the parts fiche on their website. One that I use is http://www.alpha-sports.com/suzuki_parts.htm as it seems to be the most accurate; however, I'll also use the one at www.partsoutlaw.com or my local store.

[Steve]

Yep, 12 poles on the magnets pair up with 18 poles on the stator.

If you had a 12-pole stator, you would need an 8-pole magnet.

The assembly date would be on the VIN tag on the steering neck.

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