Honda guy with a Suzuki: GS550 project

[Old Colt]

Can you do the top end in the frame or does the engine have to come out? Can I do head and possibly base gasket without pulling the engine?

Yes you can top the engine in the frame, no issues with that. The engine does pull out easy enough though should you want to clean everything up.

[Scott S]

I'm going to take a closer look when I get time. I may just do the head/valves/valve cover.

[Scott S]

Thought I'd add a quick update...

I wonder how one goes about denting a header like this? You can also see the remnants of the oil all over the cylinders, and that's after I gave it a quick clean. Definitely be doing some top end gaskets and seals on this one.




That's a shame, too, as it's only the one pipe and the rest of the exhaust is in good shape.

[Scott S]

I was told that the bike probably had "electrical issues'. Yeah....ya think?

I found a good used main harness and RH control on eBay for $36 shipped (for both). That's well worth it vs. sorting out this mess.

[Scott S]

That one bare wire is some hard copper wire, like you'd find inside household wiring or something. And the RH control had been opened up (probably in an attempt to bypass the start button or kill switch). The parts were mostly there, but it was missing all the tiny little screws and such.

One thing that did concern me was a rather large blister at the left rear of the gas tank, right where the seat touches it.
The tank is very clean inside, looking in the filler neck. The gas doesn't even smell that old.
I was afraid to go poking around the paint blister in fear of spilling gas all over the garage. I simply haven't had time to drain the tank yet. And poking the blister with my finger, it felt rather hard.

One night after work, I couldn't stand it anymore and starting flaking back the paint with a small screwdriver. The GOOD news is, it was just bad bodywork. There's surface rust underneath, but the tank itself is very solid. Whew!

[steve murdoch]

At least you got caps on your wiring butchery.
My last project had a bunch of aligator clips for connectors.

[Phred]

Love the work you did on the Honda's. I just bought a 78 Goldwing, will be picking it up in the spring when the snow is gone. As for sourcing parts, you might want to check out Z1 Enterprises. I found most of what I needed there when rebuilding my 850. They deal strictly in vintage Japanese bikes. Good luck with the rebuild. Looking forward to seeing what it looks like when finished.

[Old Colt]

On that header tube, depending on your resources, cut the tube right through the crease. Metalwork each end to be round again then work at making them lineup with each other and Tig weld them together. Done well it will be hard to see the repair.
To me a single crease is not a difficult repair compared to a crushed collector which generally are fully repairable as well.

[Scott S]

This is/was a chrome header. I suppose I could wrap it after the repair, but I'm not really a fan.
And coating it would cost about as much as a new exhaust.
I'll mull it over, but replacement might be the best option.

[Chuck78]

Make sure to offer that thing up for sale on here if you do get a new exhaust. MAC is the only one here in the United States that I am aware of that still makes pipes for GS550's.
I think you were the one that was asking me about OEM GS550 exhausts. It's still -1 degrees Fahrenheit here, but the forecast next week looks very promising for garage time!
However, I would encourage you to repair that header though, that's a fairly unique piece! The head pipes definitely spell out kerker, I didn't remember the collector making such a drastic sweep coming out the side, however. I'll see if I have pictures of the 550 that I restored last June, it had a kerker header on it, but the pipe on the side look more like a Vance & Hines than yours, but was definitely a kerker.
I would repair that head tube, and look into having it rechromed or at least some kind of ceramic powder coating. Do you have a bead blaster or sand blaster?

The 550, from my experience with 1977 - 1979 models with vm22 carbs, responds incredibly well to K&N pods, and free-flowing aftermarket exhaust. Propoperly jetted carb with this configuration will blow your mind as far as the engine manners before and after, substantial increase in power! And they sound amazing with those camshafts through an aftermarket exhaust!

The big mod to do to these however is to find the top end off of a GS650G shaft drive, and clearance the 550 cases to fit the 650 cylinders, and use a custom thickness .8mm base gasket, & 550 can sprockets. 550 cams for higher end power and a very snarly aggresive exhaust tone, re-degreed 650 cams with 550 cam sprockets for more street torque. THIS would make you not even care to ride your Honda's much anymore! 73hp stock from the 650's 673cc top end! Add K&N filter or pods, Dynojet kit, aftermarket exhaust with performance baffle... and this will be your #1 go-to bike without a doubt.

we had a batch of custom order Wiseco gs650-740cc pistons made last year, and hopefully will have several members with these hybridge middleweight beasts on the road in 2018!

Dynoman Performance offers a custom order 630cc (+4mm overbore) kit of JE Pistons for the 550's still, if you are looking to really up the ante! I do not know of anyone who has run a set of these, as they are fairly expensive since they are basically a one off custom order item. This would eliminate the hassle of trying to track down a 650 top end, but the 650 head and piston design is much more advanced, and that is why it makes one horsepower more than the first generation 750.

Good luck with your build, feel free to drop in with any questions

[Chuck78]

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!

[Chuck78]

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

[Scott S]

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.

[Scott S]

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.

[Kiwi Canuck]

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