1980 GS850 Rebuild

[twerth]

I'm sure this will be a dumb question, so I searched first but didn't find a solution.

I'm working on my tail and tag lights, and I'm not getting power to either (brake light works, so ground is good). I have the FSM wiring diagram and the colored wiring diagram from BikeCliff's website. They both show a brown wire to the tail light and a grey wire feeding the tag light. Both diagrams show these two wires going directly to the ignition switch. When the switch is turned on, the grey and brown wires are contacted according to the diagrams. but I don't see a connection to power anywhere on either diagram. What am I missing? Where does current get into those circuits?

Thanks.

[Steve]

They both show a brown wire to the tail light and a grey wire feeding the tag light. Both diagrams show these two wires going directly to the ignition switch. When the switch is turned on, the grey and brown wires are contacted according to the diagrams. but I don't see a connection to power anywhere on either diagram. What am I missing? Where does current get into those circuits?

This is almost embarassing to admit, but I use that wonderfully-enhanced diagram and the FSM a LOT. And, I have an '80 850G. I know that the gray wire feeds the tag light and the brown wire feeds the tail light, but have never noticed that nothing feeds the two of them.

Near the bottom-center of that diagram, just above the starter motor, is a four-pin connector. One of the wires on the top side of that connector is a gray wire that feeds the speedo and tach lights. It is supposed to also have a connection dot where it crosses the gray wire that feeds the tag light.

If that connection is made, when the ignition key is in the ON position, power will come from that connection to the ignition switch, then feed the brown wire for the tail light. When the key is in the PARK position, the red wire that comes from the MAIN fuse will be connected to the brown wire to turn on the tail light and nothing else.

I examined the Suzuki manual very carefully and was surprised to see that the only connection in those two lines was where the brown wire had a branch that goes to the headlight bucket.

The manual does NOT show the connection in the diagram for the '79 G on page 12-30 (page 269 of the pdf file).
The manual does NOT show the connection in the diagram for the '80 G on page 14-58 (page 329 of the pdf file).
The manual does NOT show the connection in the diagram for the '80 GL on page 15-10 (page 339 on the pdf file).
The manual does show the proper connection in the diagram for the '81 G and GL on page 16-27 (page 366 in the pdf file).
The manual does show the proper connection in the diagram for the '81 G and GL on page 16-46 (page 385 in the pdf file).
The manual does show the proper connection in the diagram for the '82 G on page 17-37 (page 422 in the pdf file).
The manual does show the proper connection in the diagram for the '82 GL on page 18-32 (page 454 in the pdf file).

I find it interesting that the '81 has two separate diagrams that are both labeled for the G and GL models. The GL models never did have a separate tag light. The diagram on page 366 is actually for the '81 G, the one on page 385 is for the '81 GL.

Now (finally) to your problem. Look under the tank on the right side near the coil, you should see that four-pin connector. Verify that you have power on the gray wire there. If you don't, check the orange/red wire in that connector. If you don't have power there, check your fuses.

.

[salty_monk]

At a minimum I'd be replacing those 40 year old brake lines... and popping out the pistons to clean behind them.

It's amazing how much gunk gets stuck in there..

[twerth]

Fixed it! Well, not really, but I found the culprit. The heavy gauge orange/red wire from the fuse box isn't contacting all the time. I'm not sure if it's a problem in the connector or buried somewhere in the taped up harness but jiggling during checking with my test light caused it to start working. When it's on line, everything works. I'll track that down, wrap up a few other loose ends in the wiring, and then move on to the carbs. I have new manifolds on order, and they should be here today. Incremental progress!

[maisf]

Someone said to me when I first got here:

"Check the connections, then the connections and don't forget the connections."

Hahaha...

I cleaned every connector / plug with contact cleaner, brush them out, more contact cleaner. Replacing a few that were just falling apart.

That cleared quite a few gremlins for me too!

I'm happy you're getting out of the woods.

I have to order a few things as well this winter, air intake boots, intake seals, etc.

My bike is ready for winter, it's getting near freezing temp already up here. Tank is full, stabiliser in there...
Hoping for a few last rides then it's gonna be the winter tarp and plugging the battery.

Take care!

Frank

[twerth]

I've spent a little more time tying up wiring loose ends, but it's still a little flakey. I'm thinking when I do a complete tear down, I might unwrap the harness and give everything a good inspection and clean up. As it is, it's the kind of thing that could leave me on the side or the road (or on fire).

I also installed the new manifolds. I didn't run it long enough to thoroughly warm up, but there's a noticeable improvement in the way it runs. Score!

I'm still at least two weeks from able to ride, so I'll go ahead and adjust the valves and then sync and adjust the carbs. By the time I'm back on my feet, the bike should be as well.

I didn't mention before, but this isn't my first GS. Here's a shot of resto I did a couple of years ago. 1983 GS1100es.

2018-02-03 12.44.53.jpg

[Steve]

Nice paint on the ES.

.

[twerth]

Nice paint on the ES.

.

Thank you! I did that myself. That was a fun bike. You really need to see the "before" pictures to appreciate the transformation.

[Steve]

The ES was a one-year-wonder, pretty much like the '78 1000E, which was known as the "Skunk". The ESes that came here were all blue on white. Not sure if there were other color schemes in other countries. It is somewhat amusing to see the efforts that some will go through to duplicate the stock blue and white EXACTLY, and here you come and show us what appears to be a couple different shades of gray. Done very nicely in the stock pattern, it REALLY looks good.

.

[twerth]

The ES was a one-year-wonder, pretty much like the '78 1000E, which was known as the "Skunk". The ESes that came here were all blue on white. Not sure if there were other color schemes in other countries. It is somewhat amusing to see the efforts that some will go through to duplicate the stock blue and white EXACTLY, and here you come and show us what appears to be a couple different shades of gray. Done very nicely in the stock pattern, it REALLY looks good.

I bought the ES in running, but pretty rough shape. It was blue and white like you mentioned, but showed its age. The seat had been recovered in blue crushed velvet, and the unobtanium gauges had been smashed. In my opinion, grey with a splash of color always looks good, so that's what I did. It was a project and I eventually had to sell it (wife say's I can only keep one), but it was fun while it lasted.

Back to the GS. I checked the valves late last week. The first one I checked was on the loose end of in range (0.07mm), so I felt pretty good. But, all the rest were super tight (now I'm more concerned about the one that was in range). I was able to get two more in range by swapping shims around, but I had to order new shims for the rest. They should be here around mid-week. I also found that my petcock has a slow drip, so I'll be messing with that in the meantime. I may end up getting a new one, but I'll try to repair first. It's slowly coming together.

Here's a shot of another project, also from a couple of years ago. This was supposed to be for my son, but he lost interest. What's wrong with kids these days?! I'd have been thrilled to death if my dad had done something like this with me! Anyway, I'm thinking about something similar for the GS, but I think I can get the proportions a little better this time. I feel like the tail is too short on the KZ. Learning all the time!

IMG_2665.jpg

[twerth]

...and another from the side.

IMG_2671.jpg

[twerth]

Valves adjusted, carbs synced and adjusted, tank and seat are installed. The only problem is that the doctor said I should stay off bikes for another month. But the weather was nice, so screw it! I took it for a spin around the neighborhood, and it ran great! A few things still need adjustment, the biggest concern being the clutch. It was a little tough to get into neutral after it had warmed up. Otherwise, it was a really nice and smooth ride.

A big part of the reason for taking it for a ride was to locate the oil leaks the PO had mentioned. I was afraid I would be looking at a base gasket leak, but everything looks tight and dry. The only leak (and it's a good one) is from the tach cable connection. The PO had removed the cable and plugged the socket with what looks like hard silicon. It's not sealing, and since it's on the front of the engine the oil makes its way everywhere. This should be cheap and easy to fix.

Another milestone checked off, and time to spend more money. Next step will be to get it street legal and put some real miles on it.

She's still not much to look at, but here's a shot I took after I got back from the shakedown cruise.

2020-11-14 15.37.58.jpg

[twerth]

....and another one of my old projects. 1982 Virago 920.

2014-08-02 09.19.13.jpg

[twerth]

Over the last couple of months, I've been able to put 50-75 miles on it, and it looks like I've still got an oil leak (leaks?). Maybe base gasket, but I was reading another post about the cam chain tensioner being a common problem. Once the weather improves, I'll clean the engine so I can pinpoint it.

Also, I'm probably looking at a new clutch. In addition to the problem getting it into neutral, I can make it slip in top gear at highway speeds. So that's on my list now as well.

My biggest accomplishments are finishing up the wiring repairs, replacement of the gauge cluster (old one was toast), and I've built a flat track style seat using the stock pan. There's still a long way to go, but I'll keep chipping away.

2021-01-23 10.57.06.jpg

[oldGSfan]

I used just a little of the engine dye and UV light on my GS1100E and it really helped, I thought I had a head or base gasket leak and it turned out to be two leaks from the half-moon shaped cam rubbers. Those leaks have mysteriously stopped, maybe riding swelled them, and the return feed to the turbo was spitting oil all over which was just an overzealous tightening that must have distorted the O-ring. Now it's not leaking, fingers crossed.

Over the last couple of months, I've been able to put 50-75 miles on it, and it looks like I've still got an oil leak (leaks?). Maybe base gasket, but I was reading another post about the cam chain tensioner being a common problem. Once the weather improves, I'll clean the engine so I can pinpoint it.

Also, I'm probably looking at a new clutch. In addition to the problem getting it into neutral, I can make it slip in top gear at highway speeds. So that's on my list now as well.

My biggest accomplishments are finishing up the wiring repairs, replacement of the gauge cluster (old one was toast), and I've built a flat track style seat using the stock pan. There's still a long way to go, but I'll keep chipping away.

[ATTACH=CONFIG]62303[/ATTACH]