1980 GS550L rebuild

[glenwill]

So I decided to go ahead with my winter rebuild, as discussed in this thread:

http://www.thegsresources.com/_forum/showthread.php?t=200768

Here is my bike before I started:

And here is the bike now:

So all of the parts are in labeled freezer bags, and I am going through them one at at time, cleaning, repairing, assessing.

I have not decided what all I am going to paint yet. Definitely the frame and related parts I am painting myself.

I may send the tank, side covers and fenders to be painted.

My plan is to have all reconditioning done by the end of March, and start reassembly on the first weekend in April.

This is a project with my 19 year old son, and it's been a great experience so far.

 

[glenwill]

I do have a question already. I'm making a list of parts to replace, and trying to contain costs. One of my decision points is the sprockets and chain.

I am a new rider, and I am not going to put thousands of miles on the bike this year. If I can get by reusing the current sprockets and chain, I can redirect the $$ to other work. At the bottom of this post are the pictures of the sprockets and chain.

The bike has about 16,000 miles on it. The chain says it's an RK 50SHO. Would that be the original chain? I have no idea whether the PO changed the chain, or how many miles are on the chain. From what I've read about sprocket wear, the sprockets start to look pointy when they are worn, and these don't look that way to me.

I also read that with the chain on the rear sprocket, the play in the chain should be less than 1/4". I measured it to be 3/16", as this video shows. Note that I mistakenly said 3/8" in the video, but I confirmed it is 3/16th.

Video of chain

Here's the other pix:

Front sprocket:

Rear sprocket:

And here is a picture of the chain:

 

[mike_of_bbg]

IMO you can defer chain and sprocket replacements for a while based on your pics. Looks like a non-sealed chain: I think OEM chains were O-ring. Don't expect that to last too long. Plan for one year unless you start putting a lot of miles on.

 

[Guest]

If there are any tight links in that chain just get another one. I would use your sprockets.
If you need any carb parts I have a full set of 550 carbs.

 

[glenwill]

Thanks mike_of_bbg and chef1366.

None of the links seem tight. The chain seems to move freely.

Unless someone chimes in with a contrary opinion, I think I'll keep the chain and sprockets for now, and plan to replace them at the end of the year.

Glen

 

[feelergaugephil]

Put the chain straight, then turn it on its side, (like a skipping rope) and see how far the chain bends (like a smile) if theres a lot of play, get a new one.

 

[glenwill]

Thanks Phil. I'll do that this weekend and see how they look.

I'm wondering whether I need to do anything with my carbs. This past summer I did a complete tear down, dip, and cleaning. When I took them off the bike for the tear down, they were in excellent running condition.

Prior to tear down, I removed the gas tank and ran the engine until the carbs were dry. I'm planning to polish them, but do I need to do any other internal cleaning before reassembly? or should they just work fine? They won't have run for about 5 months when I put the bike back together.

Glen

 

[cowboyup3371]

When you ran them dry did you at least run Stabil through them since you won't really get all the fuel out of those tiny passages?

 

[glenwill]

No, I didn't think to check on whether I should do anything when I disassembled.

Does that mean I need to do a cleaning again?

Glen

 

[cowboyup3371]

You might but you won't know until you try to start it up and it doesn't run right. If you are taking them apart to polish/paint then it might just be the best time to do so. Orings are fairly inexpensive from www.cycleorings.com and it only takes a few days.

 

[glenwill]

Will the O-rings be ruined and need to be replaced? I did buy them from cycle orings back in the summer when I disassembled, dipped and cleaned them. Can I just clean them up if I need to re-clean the carbs?

 

[cowboyup3371]

You can just be careful taking them back off. Although mine had been replaced two years earlier last year, I bought another set just in case I messed some up.



I needed them.

 

[glenwill]

I am making good progress. I've evaluated/cleaned/restored almost all individual components from the bike, have an organized box of screws I need to replace, a box of parts that need polish or painting.

I've degreased and cleaned all of the smaller frame components (swing arm, stands, etc) and am down to the larger frame, wheels and fenders.

After that I tackle cleaning the engine, and then it's on to paining.

Fork springs have been ordered and I'll change them this weekend.

I am evaluating my ignition module, and trying to decide if it is ok to keep. Here are some pics:

2 questions about it:

1) does this look like the stock module that would have come with the bike?
2) Are the cracks on the back a concern?

Prior to disassembly, the bike was running fine, at least as fine as a motorcycle noob could evaluate. It didn't miss or hesitate, and seemed strong.

Do the cracks indicate that trouble is coming, and I should consider replacing? Or if it is running fine, leave it in?

Finally, does anyone know of a source for a replacement front rotor? The sites I've checked with parts fiches show it is obsolete, and don't offer an alternative. Mine seems to have slightly too much runout, although without a dial gauge I am not sure.

When I would spin the front wheel with it off the ground, I heard a quiet scraping sound once in every rotation. I didn't pulse or vibrate on braking. Is this normal?

Glen

 

[eil]

The igniter: if it were mine, and if it worked fine before, I would try to seal it up somehow and put it back on on the bike. But others may disagree and say since there's evidence of physical damage, why take the chance? Guess it depends on your own repair philosophy and parts budget.

The rotor: You may go out and get a dial gauge if you're not sure. To measure is to know, right? They're not too expensive, probably less than the cost of a replacement rotor. If you didn't feel anything while braking, it's probably fine. Brake pads will always drag ever so slightly against the rotor when the brakes are not engaged. Could the sound have been coming from the wheel bearings or speedo hub?

 

[mike_of_bbg]

1) does this look like the stock module that would have come with the bike?

Yes. The printed number matches the Suzuki OEM part number, too.

2) Are the cracks on the back a concern?

Prior to disassembly, the bike was running fine, at least as fine as a motorcycle noob could evaluate. It didn't miss or hesitate, and seemed strong.

Do the cracks indicate that trouble is coming, and I should consider replacing? Or if it is running fine, leave it in?

Hmmmm....

Well not having opened one it's tough to say. Not sure if that crack would be a water infiltration risk or not. I'd definitely seal it before re-installing it.

My 82 came with an igniter that would also start the bike, run smoothly and without hesitation. However, it would also stop sparking altogether after about 30 minutes of running because it overheated, until it could cool back down. I have no reason to think yours is in that shape, I'm just pointing out there there are other failure modes for igniters other than works/doesn't. But I see no reason not to give it a go.

 

[glenwill]

Thanks Eil and Mike. I'll use some silicone to seal the cracks, and see how it goes.

I'll also order a dial indicator and see what the rotors looks like.

Another, unrelated question. I ordered Progressive Fork Springs last week from BikeBandit.com, and they showed up today. My GS550L has 2 part springs, separated by a washer.

I picked a Progressive spring that BikeBandit said fit my bike, a Progressive 416.

The springs came today, and there is only one spring per fork, and it is a little longer than just the longer of my original springs. It is no where near as long as my short and long spring put together.

I have emailed BikeBandit to find out if something was missing, but I was wondering whether anyone here knows whether I should have gotten both springs? Or can I just reuse the shorter spring?

Glen

 

[mike_of_bbg]

I picked a Progressive spring that BikeBandit said fit my bike, a Progressive 416.

The springs came today, and there is only one spring per fork, and it is a little longer than just the longer of my original springs. It is no where near as long as my short and long spring put together.

I have emailed BikeBandit to find out if something was missing, but I was wondering whether anyone here knows whether I should have gotten both springs? Or can I just reuse the shorter spring?

Hmmm, 416 sounds like a shock model, not a spring model - sounds like you're talking about the front forks though? Progressive springs usually seem to have part #'s like 11-11xx (i.e., 11-1115 I think is what I ended up buying). Make sure whatever you bought at least fits into the fork uppers.

What you'll want to do is get some PVC pipe (3/4", probably) and cut it to the correct length to fill up the remaining space plus maybe 1-2" of pre-load on the spring. What you're looking for is about 1.5" of "sag" when on the bike, in riding position (1.5" is about 25% of total fork travel). The springs are not custom made, there's just a recommended size of spring (diameter, length, and spring rate) for your bike. The length is not going to match, as you have noticed. You'll have to adjust spacing from there.

BassCliff has a write-up from changing his stock springs to Progressives on his site. In it he shows making the spacers and measuring sag. Here's the direct link to that PDF:

http://members.dslextreme.com/users/storagecliff1/images/Install_Progressive_Fork_Springs.pdf

Oh, and for your info/entertainment, here's the list of parts from Progressive Suspension. The first two pages are fork springs, and yes, 416 is a progressive rear shock model.

http://www.progressivesuspension.com/pdfs/7100-105.pdf

 

[glenwill]

Hmmm, 416 sounds like a shock model, not a spring model - sounds like you're talking about the front forks though? Progressive springs usually seem to have part #'s like 11-11xx (i.e., 11-1115 I think is what I ended up buying). Make sure whatever you bought at least fits into the fork uppers.
...

Thanks Mike. I think I may be ok, but I want to confirm.

First, here is the product on the BikeBandit.com site:
http://www.bikebandit.com/progressive-suspension-416-series-fork-springs?m=21461

Even in the link name you can see they call it a 416 series fork spring. However, when I looked at the Progressive box that came with the springs in it, it identifies it as a model 11-1106, which according to the Progressive site is the correct model number.

Just to be clear, though, here is a picture of my springs:

At the top is my current 2-part spring, which is 25" long.

Below that is the new spring, which is 19" long. So I may need a piece of PVC about 6" long. Is this reasonable?

Glen

 

[glenwill]

I am further confused by the fact that the Progressive page for my bike says that a spacer is not required for the 11-1106:

http://www.progressivesuspension.com/prodSearchResults.aspx?yearID=1980&makeID=45&modelID=846

 

[mike_of_bbg]

Glen,

I called Progressive about the springs I bought. First, the wrong ones were in the package (may have been a returns issue with the reseller, perhaps not their fault). When I did finally get the correct springs, they were thinner than they needed to be (note the 11-1115 has 22mm OD IIRC) were not long enough although it said "no spacer required". What they came right out and said was that most of their database was gained from acquiring another company and they really don't have any idea where the suggestions came from. I still installed my springs (with PVC spacers) and they work fine and handle much better than the originals. The 1106's look like they should be fine for your application, the 25mm OD should fit. Of course you're going to need to add spacers.

The bottom line of what I'm saying is that there's no hard-and-fast rule about this - you're going to have to do a bit of experimentation. You'll notice that the Progressive page just says "GS550", and probably doesn't even have an option for L, E or whatever sub-model, despite the fact that the L is going to use a longer spring. Those springs are going to work, you are just going to have to find the right pre-load that works for you and ignore Progressive's note on there. Six inches isn't an unlikely amount for the spacers at all; don't get all crazy with pre-load and make 'em a foot long so you don't even have 6" of travel and you'll be OK. A good rule of thumb for starting I think is to size the spacers so they're about 1" out of the forks at full extension and no load (that will be about 1.5" of pre-load after installation). You can cut the spacers down later if it's too much pre-load, or add washers (or just re-cut longer spacers) if you want some more.

Also, may I suggest not leaning on Bike Bandit too heavily? I have bought a few things there myself, though not so much. Things like that page (no model #), or the fact that they don't use real Suzuki part #'s for OEM parts really p1ss me off. You can usually find better prices for stuff than there - those same springs from powersportsuperstore would have run you less than $70 shipped.