• Required reading for all forum users!!!

    Welcome!
    Register to access the full functionality of the GSResources forum. Until you register and activate your account you will not have full forum access, nor will you be able to post or reply to messages.

    A note to new registrants...
    All new forum registrations must be activated via email before you have full access to the forum.

    A Special Note about Email accounts!
    DO NOT SIGN UP USING hotmail, outlook, gmx, sbcglobal, att, bellsouth or email.com. They delete our forum signup emails.

    A note to old forum members...
    I receive numerous requests from people who can no longer log in because their accounts were deleted. As mentioned in the forum FAQ, user accounts are deleted if you haven't logged in for the past 6 months. If you can't log in, then create a new forum account. If you don't get an error message, then check your email account for an activation message. If you get a message stating that the email address is already in use, then your account still exists so follow the instructions in the forum FAQ for resetting your password.

    Have you forgotten your password or have a new email address? Then read the forum FAQ for details on how to reset it.

    Any email requests for "can't log in anymore" problems or "lost my password" problems will be deleted. Read the forum FAQ and follow the instructions there - that's what we have one for...

  • Returning Visitors

    If you are a returning visitor who never received your confirmation email, then odds are your email provider is blockinig emails from our server. The only thing that can be done to get around this is you will have to try creating another forum account using an email address from another domain.

    If you are a returning visitor to the forum and can't log in using your old forum name and password but used to be able to then chances are your account is deleted. Purges of the databases are done regularly. You will have to create a new forum account and you should be all set.

Honda guy with a Suzuki: GS550 project

  • Thread starter Thread starter Guest
  • Start date Start date
As far as the electrics go, one thing you should know that I haven't seen mentioned here yet in your thread is that the stock regulator rectifiers on all Suzuki GS models are absolute garbage. You need to Ohm out the stator leads to each other to check to see if they are still in spec, around 1.9 or 2.3 ohms if I recall(?), and test for any continuity to ground, just to make sure that the regulator rectifier did not fry the stator.
Then swap on a $45 used Polaris ATV Shindengen SH775 series style regulator, as this is a far more advanced design, as it does not run hot like a shunt style regulator rectifier which keeps the stator smokin' hot under low load demand conditions...
RM Stator and other sellers on eBay offer OEM Factory plug kits to wire in those regulator rectifiers to your bike.
For the actual regulator rectifier, search eBay for Polaris part number 4012941. You will find a bunch of used ones from crashed side by side ATVs, for about $45 shipped. What a killer deal. Poke around on here or ask about the wiring plug. Most on here at use a Triumph part number, but they are all over eBay for all kinds of different bikes that use shindengen regulator rectifiers, and very easy to identify visually. The kit comes with two water-tight wiring plugs and crimp in fittings. I solder the wires into them every time, and it works fantastic. I solder and thoroughly heat shrink every wiring connection that I make on these harnesses, FYI. Splices and crimp on connectors both get soldered in my garage...

Look up member posplayr (Jim) and click on that GS charging system health link in his signature file. Follow his minor modifications to the electrical system by doing his single point ground mod ( all grounds except for the starter motor go directly to a single point on the frame nearest the battery negative terminal, starter still goes to the battery directly). Then also look at his basic diagram for power distribution, I think it is titled "Popular rewiring for Suzuki GS." Open up the wiring harness and rewire yours this way. Also, the same as any vintage bike, you would be foolish to be doing wiring work and not separate the ignition power feed out of the harness, using the old feed to trigger a relay on which will channel direct power straight from the battery and charging system directly to the ignition and coils. This has been known to drastically improve the way many bikes of this age have ran!

One last thing about the wiring harness, follow the stator wires, if you see two extra confusing wires in the harness, early GS models, in an effort to have less excess voltage to regulate, ran one stator lead all the way up through the headlight switch and back down to the regulator rectifier. If the headlight was switched off, a spare set of contacts in the headlight switch also would just completely disconnect one of the stator outputs, in an effort to keep the voltage down and keep the engine heat down also by not having to shunt regulator output of that lead as well when there was already plenty of voltage present. Bypass this wiring Loop to the headlight switch and run your stator wires directly to the new regulator rectifier. This was a problematic design which was just a crutch for the original garbage regulator rectifier.

Make sure once you get your bike running, to test the stator output with a digital multimeter in AC, with the bike running exclusively off of a good battery, charging system on hooked. Look up the stator papers on here, a very very in-depth tutorial that members have compiled. It will tell you the ac voltage output depending on what RPM you are running. I think good range is somewhere between 30 and 80 volts AC depending on the RPM of the engine. this is the final test to make sure the stator does not have any shorts that only show up under high output levels.


oh, and look up cycleo-rings.com for the most complete carb o-ring kit you will find, and supplied to you by a member of this forum!
 
I'll make my last bit real quick here, you're probably overwhelmed on my overload of information. Pardon me, I'm just a fanatical GS nerd...
get some Sonic Springs (Rich Desmond the owner of that company is a GS owner and member of this forum), & MikesXS.net 35mm cartridge emulators for that fork if the chrome tubes are still in good shape... Tarozzi makes Fork braces for them as well.
If not in good enough shape to dump money into, try to find a clean set of late model 1989-2010 GS500 Forks and front brake caliper and master cylinder. They are lighter, stiffer, 37mm, and have a substantially better brake that most people adapt to their older GS forks anyway using a bracket kit that a member sells. The earlier versions of that fork are the preferred ones due to disassembly ease with the damper rod. You will need a racetech cartridge emulator for these. They use the same diameter axle as your GS, but you may need to get axle & spacers off of a larger GS, 850, 1000, 1100 ( you're going from a 175 mm width triple spacing to a 185mm width spacing). You will need to run these in a 1982 - 1983 GS1100E triple clamp set ( steering stops may need slight modification, not sure on 1980 frame). These are really nice because the lower triple is aluminum as well as the upper, so they are beer and lighter, and have the correct offset and the correct steering stem for your frame.
Then source a 1998 - 1999 CBR900RR brake rotor. Now you will have a 310mm floating rotor and a top-notch well proven 2 piston floating caliper that will substantially outperform the original brakes.

As for a rear suspension, the general consensus is always to go 10, 20, 25 mm taller than stock GS shock length depending on how sporty you want your steering. They definitely feel substantially lighter and more responsive and tight turns when you go up 20 mm on shock length. Then you can find tune the rake and trail by dropping the triples on the fork tubes slightly if you want more.
Another tip that really improves the steering is to run Bridgestone battle axe bt45 tires. The fronts they offer are consistently always the shortest diameter tire of their specified size, which helps reduce trail and makes them steer even more sporty. Not to mention these are phenomenally gripping tires, and the rear is a dual compound so that you can have the ultra sticky rubber on the sides but not wear your tire out in 3000 miles of flat straight road riding..
There's one other tire that I have been curious about, and that is the Continental classic attack radial that is designed for our bikes. I think they only come in one size each, and it is what will fit your rims if you have a 18 rear and 19 front. Some of the 550's have a 17 rear. L models will have a 16 rear.
My current pick for best replacement shock is the YSS E-302. Rebuildable, excellent construction, top-notch valving... call up Klaus @ YSS-USA.com to get custom spec spring rates for your weight and bike. Cheaper non rebuildable $200 Hagon or Progressive shocks are generally the lowest you want to stoop with rear shocks on these.

Sorry to spew all of this information out at once at you! Saturday morning breakfast leisurely time here.

Best of luck,

Chuck
 
Man, tons of great information there!

I've read up on the 650 top end stuff. Current plans just call for a stock clean up/ re-seal on the top end.

I am aware of the stator and charging issue stuff. I've skimmed a few of the stickies and threads on it. The current wiring harness is in bad shape. I have a replacement and I planned on digging deeper into that stuff as I install the new harness. I'll do any tricks and upgrades then.

That front end stuff sounds neat. Might have to make a list and start collecting parts for a future swap. What fender do yoh run? The GS500 fender?

And on the exhaust: I'll definitely take a closer look and more pics when I remove it. If it's worth saving, I'll hang on to it. I did just find a pretty nice set of stock 4-2 pipes and they're on the way. I'll go with those, at least initially.
 
Got the carbs and engine pulled. That was a little bit of a chore, with the old, hard rubber around the carbs. Had a few stubborn screws and it was obvious someone has been in there before me.
The wiring harness is definitely fubar, but I have another. The frame is dirty and the engine is FILTHY. Very oily and messy. I've already dropped off the carbs with Rick at Oldskool Carbs.
Time to get this thing cleaned up so I can get started.


 
I saw you asked for vendors in one of your earlier posts, not sure if you got any responses, so here are my two.

I use Parts Outlaw as my go to vendor and Z1 Enterprises is also very good, but you need to call them as they don't have the Suzuki fiches listed on their Web Site.

https://www.partsoutlaw.com/oemparts/l/suz/50d3f5c0f8700230d8b4c74d/1980-gs550e-parts

https://www.z1enterprises.com/motorcycles/suzuki/gs550/gs550et/1980

You do nice work on those Hondas, hope the GS 550 comes out as nice.

David
 
When your hands look like this just from removing the wiring harness, it's bad.


 
This is just one of about fifteen reasons I could find that the P.O. claimed to be having electrical problems. In their defense, they had added about half a dozen extra ground wires, some made with what seems to be house wiring or a coat hanger!


 
This is the rear of the cylinders AFTER an initial cleaning. The front side is worse.


 
The front sprocket is waving and saying "Hi!".


What are some reasons for all the goo back here? I've seen shift shaft seals cause this. Can that seal be changed on the GS550 without splitting the case?
I plan on doing a MUCH deeper cleaning, but it's supposed to rain for the next few days.


 
I've had 5 550's over the years. I have three restored in my garage and a GS650G 82 on the go (two actually). The goo in the photo is pretty typical of what I've seen when I peel back the layers to clean. Likely oil/lube from the chain and possibly grease from the worm gear? From scanning your posts you've got a great handle on this project and there isn't likely much I can tell you that isn't in the other posts but I will say that on an 82 GS550L I have, I converted it to a "T". The GS550T was a one year model for 81. It was my first bike back in the day. I still like it as it has gets away from the Japanese chopper look with the stepped seat. The T seat is pretty much flat and a better ride for the shorter frame of these smaller bikes. Riding an L for me is too cramped.

I've inserted a picture of my L to at T conversion. All I had to do was make a new seat latch plate out of some metal I had on hand and use the T side covers as the angle of the seat is different. Also, seats for the T that are in good shape are like hen's teeth to find so I had Pitt Replica's make a new cover which he now sells on eBay for about $90. They're well made and well worth the money as they're an exact replica unlike some of the other covers out there.
IMG_0636.jpg
 
The front sprocket is waving and saying "Hi!".


What are some reasons for all the goo back here? I've seen shift shaft seals cause this. Can that seal be changed on the GS550 without splitting the case?
I plan on doing a MUCH deeper cleaning, but it's supposed to rain for the next few days.



Normal, the way the chain 'cage' (more of a box) is constructed dirt accumulates very easily in there.

Which seal are you referring to? Oil pan, stator cover? Then yes.

Also, that sprocket is totally worn out, but methinks you know that already.
 
The seals can all be changed from the outside without splitting the cases on a GS. GS engines are really designed well, very easy to work on

And by the way, your cam chain tensioner needs a rebuild - the main oil seal, and the set screw O-ring for sure. There is a third O ring that takes a 30 or 31 mm socket to access, it's never really the culprit, but can swap that as well at the same time.
 
http://www.bwringer.com/gs/camchaintens.html

The block gasket part number is for an 850 there, but the rest fits 99% of GS cam chain tensioner aside from 1989-2010 GS500's and the first few months' worth of 1977 models use a larger setscrew with a sealing washer that's not as good, but on the parts fiches.
The smaller setscrew with o-ring groove is on most GS's. for some reason Suzuki excluded the cam chain tensioner internal parts of that type from most of the parts fiches, so that link is your only source for those OEM part numbers.
 
Last edited:
Yeah, I knew the sprocket is worn out, hence the "wave" reference. Being cheeky a little bit...or attempting to be!

I've repaired several leaking shift shaft seals, and even a couple of main shaft seals, on XS650's and a few CB500/550's. Good to know that's an option here, too. I'm not sure if it's actually leaking or just never been cleaned in there before.

I've read up on the tensioner rebuild. It very well may need it, but there was a LOT of oil coming from around the head gasket and valve cover. There's also black silicone goop oozing out of places where there should only be a gasket. I'll take a good close look at everything when I get in there.
 
Yeah, I knew the sprocket is worn out, hence the "wave" reference. Being cheeky a little bit...or attempting to be!

(...)

lol, completely missed that line, just saw the pic and the text below. Carry on then!
 
It's been a long time since I updated this thread and, well, there's a reason for that. It seems I got distracted and went in a completely different direction.

I made the mistake of learning that you can transplant a later model engine into the 550 frame. Shortly after that, I picked up this 2000 GSX750F/Katana for cheap.



Robbed it of it's engine, wiring harness, suspension, wheels and tires...

 
Found a Bandit 600 triple tree and modified it slightly for bar risers.


 
Had some custom brackets and spacers made and installed the GSX750F engine.






 
Since I won't be able to run an air box, I picked up a set of earlier style BST36 carbs from a '95 model. These are supposed to play better with pods.
Rick at OldSkoolCarbs did his thing to them. They will eventually be jetted properly. (I HIGHLY recommend Rick, BTW).




And I'll use K&N filters.




And a stainless Yoshimura slip on with the factory header, after I smooth out the factory welds, a trick the GSX guys do for more flow.




The GS550E was rated at 49 H.P. and the GSX750F was rated at 96 H.P. With the aforementioned mods and maybe a timing advancer, I'm hoping for at least 100 H.P., or 80+ at the wheel.
 
Back
Top