1979 GS1000 Project

[tinactin]

I bought a 1979 GS1000 about five years ago. I rebuilt the carbs and most of the top end (with lots of help from TGSR), rode it for two years, and then left it to rot. The bike has been sitting in my girlfriend's garage for about a year, so the time came for me to either sell it or fix it up and ride it home. So I'm fixing it up.

Started out pulling the carbs, since I left gas in the tank and figured they were wrecked after three years.

No "before" photos. Just imagine this with a scuffed & peeling blue gas tank and a reasonably decent seat.

The carbs were pretty filthy on the outside, but the internals weren't too bad. The bike came with a manual petcock and I guess it was turned off.


I was going to dip the carbs, but after tearing them apart I didn't think it was necessary. I used spray can carb cleaner and lots of rags. I made sure I could see through all the jets and that all the passages in the carb bodies were clear. Got everything nice and organized with an egg carton I snagged from my local breakfast burrito joint.


The bike came with pods and a Kerker 4-into-1 exhaust when I bought it. The jetting I found in the carbs is 112.5 mains and 20 pilots. From the Pods Pipe Panic! thread, it looks like stock jetting is 95 main and 15 pilot, and I remember the bike seemed like it was running rather rich (clouds of exhaust smoke when opening up the throttle on the highway, little to no torque at low RPM for setting off). Do these seem like reasonable jets? I'm not sure.

The bike also always had the clutch rattle in neutral at idle, and there were a couple instances of what felt like clutch slippage when setting off at high acceleration, so I decided to open up the clutch basket and have a look.

Turns out the hub nut was rather loose. After fighting with the bent washer for a little while, I managed to get everything disassembled.

Three of the springs in the back of the hubs were, of course, loose enough to shake around. I got in there with a big flat-bladed screw driver and stretched them out until they were snug. One of them was stubborn and still rattles a teensy bit, but I'm not too worried.

While I was in there, I measured the clutch springs and discs. Everything looked fine.

Clutch spring service limit is 1.46in.


Drive plate limit is 0.09in.


While I was reassembling the clutch, I managed to shear a clutch spring bolt off in the pressure plate. That's what I get for using a torque wrench at the absolute lowest end of its torque range. Fortunately, a trip to Ace Hardware yielded six new bolts and fender washers.

The new bolt next to an old bolt and the sheared-off head.


Be sure to install the clutch release rack in the pressure plate before torquing down the clutch spring bolts.


I also snagged some M10 castellated nuts for the motor mount bolts. The rear motor mount bolt had a nylock nut on it, and the front bolt didn't even have a nut on it.


While I was around the motor mount regions, I noticed that I was missing the M10x60mm lower motor mount bolts and accompanying teardrop nuts. I'll have to pick some of those up.

Finally, I tore off the valve cover and checked the tappet clearances. I shimmed the tappets when I bought the bike, but haven't checked them since. I don't have a set of metric feeler gauges (and the sets available on McMaster-Carr don't even go down to 0.03mm), so I went by the US Customary conversion of 0.001-0.003in. Unfortunately, the thinnest gauge I could find was 0.0015, so I just used that along with a 0.003 and 0.004 gauge to make a kind of three-way go/no-go gauge. All the tappets look good except the #2 intake valve, which is right at 0.004 clearance.


That's all for the first weekend. I have o-rings coming in for the carbs from cycleorings.com and I'll be placing an order with Z1 tomorrow for the carb gaskets, new SS brake lines, and new points and condensers (though I'm thinking about getting the Dyna-S electronic system. Worth it for $133?). Next weekend I'll re-assemble the carbs, drop the oil pan and clean out the screen, then button everything back up and hopefully have it running. Of course, photos will follow. I know everyone likes photos.

Comments, criticism, and feedback are solicited and appreciated!

[azr]

Looks like you're getting some good maintenance done. The clutch slippage you described will be from your clutch springs, at $2 per spring new from Suzuki it's well worth replacing them and get ride of the high RPM slippage. The jetting for your carbs seems a bit big on the pilot end. I would have thought a 17.5 pilot would have been big enough and possibly a bit of a bigger main jet, but maybe not. You would have been able to tell if the main jet needed to be bigger as the bike would have been stuttering at high RPM as it was hunting for more fuel. That large pilot is likely the cause of your low end issue.

[tinactin]

Thanks for the input! I just got off the phone with Mike at Z1. He was super helpful. Gaskets, points, condensers, and some new jets are on the way. I went with 15 and 17.5 pilots, and 110 and 115 mains. He said that, based on the stock setup (95 main and 115 pilot) and my mods (pods and pipe), those should put me right about where I want to be. Mike also suggested I check the spark advancer when I have the carbs back on, and make sure that it is advancing 20 degrees at 2500rpm.

In the meantime, I need to figure out what to do about the front fender and gas tank. I've been riding the bike without a front fender since I bought it, but I have the original fender. It was stripped and sanded when I bought the bike, but it's gained a couple rust spots over the years.


I'm not sure if I want to prime & paint it or have it chromed. I'm leaning towards having it chromed, but I think it would be more expensive. I'm really impressed with the results that some folks here have achieved with rattlecan paint, but I'm not very confident in my abilities...

As for the gas tank, the decals are all flaking off, there are a number of pretty large spots where the paint has flaked off, it has a good dent in the front, and there is a pinhole leak in one of the bottom seams. On the bright side, the interior is in great shape. I will probably need to strip it, weld the leak, bondo the dent, then have it painted. Does anybody know of a good shop in the Denver area that might do this kind of thing for less than $500?

[steve murdoch]

Great to see maintenance being sorted before cosmetics.
Keep going.
I would contact Chuck Hahn on this site about your gas tank.

[chuck hahn]

Take the tank to a body shop or dent repair / pulling place first off. They can either push as much of the dent out as possible or fill the tank with water and use the stud gun and pull the dent as much as can be done. They fill with water so the gun just doesnt blow a hole in the thin metal.

As for the seam leak.

1.. Just use some acetone and swish it around for a day to soften and loosen any crud laying in there along the bottom that you cant see. Repeat till the acetone no longer comes out discolored..note that the hole may start leaking more so sit it over a metal pan ( acetone will eat plastic ) so as to catch anything dripping.

2.. Get a gallon of PREP AND ETCH from Lowes or Home depot and dump in and fill the rest of the tank with water. This will further remove any small rusting spots and etch the metal in prep for the new liner. rinse well and dry the inside of the tank extremely well as fast as you can. Any moisture left behind will hurt the tank liner application. Heat gun or a hair dryer in the filler hole works well for this task.

3..Put two bolts in the holes for the petcock and coat them with some grease or vaseline in the threads so tank liner doesnt stick to them. This keeps the holes clean after you do the tank liner. Get a pint of POR 15. Tape down the offending seam with duct tape and dump in the POR 15 and roll the liner around..do this many many rotations to see that you fully coat the entire inside of the tank. Drain excess out the petcock hole as much as you can get out. Roll the tank around and run the excess to the petcock hole as well as you can. Let it set a full 24 hrs as the instruction say..or even longer is even better..so the liner has time to cure and adhere to the tank.

4..Now remove the bolts in the petcock holes and youre done. The liner will fill in the seams and any other tiny spots and there is no need for welding or soldering of the seams.

[tinactin]

Awesome, thanks for the reply Chuck. Looks like you may have just helped me save a ton of money. I'll find a dent repair shop and get the tank to them this week, then hopefully do the tank liner this weekend. Is this the right stuff?

[chuck hahn]

Tank liner..1 pint will do it.

http://www.amazon.com/POR-15-FUEL-TANK-SEALER-PINT/dp/B001NG8I86/ref=sr_1_2?ie=UTF8&qid=1435101542&sr=8-2&keywords=POR+15+tank+liner

Prep And Etch to dissolve any lingering rust and prep the metal for the POR 15...

http://www.homedepot.com/p/Klean-Strip-1-gal-Phosphoric-Prep-and-Etch-GKPA30220/100406369

[tinactin]

Cool, thanks again. I ordered the liner and I'll pick up the prep & etch on my way home. I also happened to be perusing craigslist and found a GS1000 fender for a few bucks that looks like it's in much better shape than mine, and it's on my way home from work. I'll post some photos after I pick it up. O-rings should be waiting for me tonight, so I'll be putting as much of the carbs back together as I can without top & bowl gaskets.

[chuck hahn]

After some acetone to loosen and get as much gunk released, do the etching for maybe 4 or 5 hrs and check it. Real bad tanks I have let sit all night but yours doesnt sound all that bad.

[tinactin]

Okay, great. I found a shop near my work that I think can pull the dent. Hopefully the sealer shows up by Friday so I can do the tank this weekend. O-rings didn't show up today, so the carbs aren't back together, but I did get the clutch cover back on. Those phillips heads are getting pretty torn up, so I'll probably snag a set of stainless fasteners off Ebay. I think I saw a full set for $35.

I picked up the new fender and it's great. It has a couple barely noticeable dings in it, but it's leagues better than my old fender.


Now I have to figure out what to do with the old one. Paint it? Sell it? Turn it into a dining room centerpiece?

I snagged some M8-1.25x16mm stainless steel bolts for the fender and slapped it on the fork. It looks great. No more impromptu showers whenever I ride through a puddle.


Hopefully the carb O-rings show up tomorrow, but the order from Z1 with the carb gaskets (among other things) is delayed and might not ship for a while. I have my fingers crossed that everything shows up before the weekend, but it's starting to look grim. We'll see what happens.

[chuck hahn]

Look into stainless allen head kits. I do believe Z1 has them available. Comes with everything for all the covers. That may not include the cam cover, so ask about that when you investigate.

[tinactin]

Called Z1 yesterday and added a stainless bolt kit to the order. Sounds like it's not even going to ship until the beginning of July, so it's going to be a bit longer than I thought before I have the bike running.

Last night I dropped the oil pan to replace the gasket and wash the pickup screen. The bottom of the pan was full thick deposits of sludge that took a screwdriver to scrape away.


Also found this stuck to the bottom of the pan.


Cleaned out the pan, washed the pickup screen, and I'll be putting it all back on tonight.

[tinactin]

Progress stopped for almost a month while I'm waiting for parts from Z1. I also placed an order with Chaparral motorsports for a new right-side cover, clutch springs, and the lower engine bolts and accompanying teardrop-shaped nuts. Also snagged a couple clutch hub washers, since the old one looked like it had been bent and unbent a few times before I touched it. I was really impressed with their prices - $31 for the side cover, new, when I've been seeing cracked used ones on ebay for around $150. It showed up with a long but shallow scratch on the outside, but I don't think it will matter since I'm going to be sanding and painting it anyway.


Got the clutch springs and the new motor mount bolts installed last night, and replaced the clutch hub nut washer with a new one. Still waiting for carb gaskets, new points, etc to show up from Z1. Hopefully I see them sometime next week. At this rate, I might even get a whole month of riding in before the snow starts falling!

[steve murdoch]

Odd that the parts from Z1 are taking so long.
I have had fantastic service from them on many occasions.
Where do you live?[if you put it in your signature a helpful GSer might be nearby]

[tinactin]

Z1 parts finally came in. As I understand it, they had some unexpected trouble getting a few parts from their vendors, so they didn't end up shipping everything until almost a month after I ordered it. Then, when I finally received the box, all it had in it was a bit of fuel line--apparently, the box had been damaged and opened during shipment, and everything had fallen out! I called Z1 and they just need some pictures of the damaged box, and shipped me replacements which arrived two days after the original shipment.

While the parts took very significantly longer than expected to ship, the customer service from Z1 was good. Steve and Jeff were very helpful over the phone through five or six calls.

On the bright side, all this waiting for parts left me with no excuse not to dip the carbs, so they all received nice long dips in Berryman's and are sparkling inside and out.

With the carb gaskets finally in hand, I was able to re-assemble the carbs last night with all new stainless socket head cap screws from Z1. They went back on the bike after thoroughly checking that the intake boot o-rings were in good condition. Right now, I'm running 112.5 main and 17.5 pilot jets, fuel screws are 1 full turn out.

One bowl to go:


I also replaced all the engine cover fasteners with stainless socket head cap screws from Z1, and replaced and adjusted the points and condensers.

Just look at those shiny new fasteners. I think they may have missed one, since the chain cover needs two of the longest ones at the top left.


I plumbed in about two feet of fuel line and poured in some gas with a funnel--some gas jetted out of the upper vent on the #4 carb as I was filling the rails. I gave the bowl a whack with a screwdriver handle thinking that the float might have gotten a little stuck, and fuel stopped spilling.

The bike turned over on the first try, without any choke. Very exciting. Adjusted the idle down to 1000-1100RPM (is the needle supposed to shake & shiver like that?), and there was a good amount of light gray smoke coming from the tailpipe. Not big clouds, but definitely hazy puffs that were easily visible. Happy with my work, I called it a night.

This morning, I reassembled everything - gas tank put back together (Never found a shop that was willing to pull the dent, and doing it myself was unsuccessful...so maybe that whole project will happen this winter), pods back on, seat back on, filled the tires, replaced the points cover and side covers, etc. This time, it needed some choke to start. I let it warm up a bit until I could turn off the choke, then started tuning the idle air screws. Interestingly, carbs #1 and #4 were rather easy to tune - the change in idle speed when turning the screws was very noticeable, so finding the highest idle was easy. On the other hand carbs #2 and #3 were a challenge...the change in idle speed was barely noticeable. I'm not sure if my method is incorrect, but I suspect I'll have to continue playing with these screws to get it perfect.

After tuning the idle air screws, I took it for a short ride around the neighborhood. It rides! There are definitely some flat spots in the throttle that need to be smoothed out, but it pulled hard and fast.

At idle, letting out the clutch slowly still resulted in no power and a stall. I'm starting to wonder if this is even abnormal behavior--on other bikes I've ridden (all newer Harleys, BMWs, and Hondas), you can let out the clutch at idle and just slowly cruise around a parking lot, but maybe for bikes this old, it's normal to require a little throttle to keep from stalling. It just makes very low-speed maneuvering difficult.

At this point, I think my next moves are to sync the carbs and tune the fuel screws. I'm thinking about picking up a colortune--does this replace the plug-chopping process, or does it just make it easier? From what I've read, plug chopping seems like a very time-(and plug-)consuming process. I think I'll also delve a bit into the Stator Papers. I have a (somewhat) new stator, coils, and R&R on there, but I'd rather find the problems now than in a wal-mart parking lot. I think I'll also throw on some braided stainless brake lines this weekend.

Miscellaneous shot of gas tank dent that will just have to wait:


By the way, in answer to Steve's question, I'm just outside of Denver. So if anybody nearby wants to ride or wrench, let me know.

Edit:
Forgot to include a shot of the whole bike now that it's back together!