Thursday, January 31, 2008

Alloy Swing Arm

The later GS1100 and Katana ('81 up) came with a neat fabricated alloy swingarm that looked a lot like aftermarket swingarms made during the 1970's. It weighs about 8 pounds less than the steel one (seriously!) and it's a lot stiffer. One would look just right on the Bruiser, giving it a touch more of that "Superbike" vibe.

There's nothing wrong with the stock GS1000 swingarm, and if I was doing a factory restoration I would leave it in place. However, I like to do easy mods when I get the chance, and this is definitely an easy mod. It's also reversible as long as I keep the stock swinger around.

I traded an extra set of Progressive fork springs that I got (long story) to a nice guy named Dennis in Connecticut for the swingarm. With the bike in pieces and lots of parts on order, there wasn't a better time to make the swap.

It's a bolt-on mod, or rather should be a bolt-on mod. My bike didn't quite have enough clearance on the left between the passenger peg bracket and the swinger. No big deal, I just used my trusty Craftsman trolley jack to push the peg brackets a little (like 1/8") further apart. Now they're perfectly even.

The other modification I made was to the original GS1000 chainguard - it's a nice plastic piece in comparison with the GS1100 swingarm's steel guard. The front hole is in a different location but it was a simple change. I drilled a new hole in the proper location and added a stainless bolt from the backside and a locknut on the outside.

I took the opportunity to grease the pivot needle bearings, re-route the brake hose and adjust the chain tension again. I also cleaned the back of the motor and bottom of the battery box since this area is normally obstructed by the swingarm.

I'll give a handling report next time I take the bike out, but it sure looks trick sitting in the garage!

Monday, January 28, 2008

Charging System

The bike seemed to charge OK, but the lights were dim at idle. They brightened up with a rev, which made be think that the stator and regulator were doing their job but the battery was weak.

At idle voltage was just 12 volts, but above 5,000 it climbed lethargically to 13.8. Within specs, but not very impressive. After a few days of charging the battery wouldn't give more than 12.2 volts, which is pretty low.

These bikes are known for having weak charging systems, though, so I wanted to head such problems off before they appear in the future, without spending a fortune. Since it was down for the engine work, I figured I'd do a little creative re-wiring.

The problems are many, but they come down to a marginal-sized stator, over-use (mis-use?) of bullet connectors, one stator phase (of three) that's completely unregulated and a regulator that's not efficiently grounded to the battery.

I formulated a plan to upgrade the weak spots of the stock system:

- Marginal stator: This I couldn't do much about - I measured the resistance of the stock one and it seemed fine. Looked fine too, when I pulled off the cover.

- Sub-optimal bullet connectors: I replaced all connectors with 1/4-inch spade terminals

- One unregulated stator phase: I replaced the separate rectifier and 2-phase regulator with a modern unit (from a Honda CBR929rr) that will control all three phases instead of just two. I wired the third phase directly to the regulator instead of through the lighting switch (and a bunch of bullet connectors).

- Poor rectifier/regulator wiring and design: I wired the regulator directly to battery instead of through the harness. The GS originally has a separate rectifier and regulator, which just adds resistance to the circuit. The 929 combined rectifier/regulator had two positive and two negative outputs - I ran one positive and one negative directly to the battery. The second positive went to the wiring harness like the stock regulator and the second negative was grounded to the starter solenoid along with the harness negative wire.

I took the opportunity to do some more cleaning of the battery box area. I also removed and painted the electrical panel for more bling. And finally, I replaced the weak battery with a nice new 12N14 battery from Wal Mart.

Now, even though the new regulator is about double the size of the old one, you can't tell. Looks good, doesn't it?

That should cure my electrical and charging problems for the forseeable future...

Thursday, January 24, 2008

Clutch Rattle

With the covers off, I had access to the clutch. I removed the springs, spring bolts and plates and found the source of my noise - a loose clutch nut. The reason for the loose nut was very clear - the stock setup uses a large lock washer under the nut that is then bent up to lock it in place. The problem with this is that the lock washer is made from soft steel so that it can be bent up. The initial torque of the big nut plus the constant shock of power transfer through the clutch eventually crushes the soft washer until it releases the tension in the tightened shaft. It's a common problem with this kind of arrangement.

After a while of floating free, the shaft splines beat up the aluminum splines in the clutch hub and it gets even more loose. The ultimate solution is getting rid of the lock washer and using a billet clutch nut with red loctite and a brand new clutch hub. I don't have a billet clutch nut or new hub, but I do have red locktite which will hopefully solve the problem. There are available, but I'll see if this works first. It's easy enough to get at the clutch by putting the bike over on it's sidestand, so I'm not too concerned about re-doing it.

I gave the steels and fiber plates a quick measurement to make sure they are OK, and they're within specs. I thought I felt a little clutch slip on one of my rides, so the springs might be getting weak - I'll change them later if it returns. The springs in the clutch were loose and rattly, but just tightening down the hub should cure the worst of the noise.

I knocked the new seal and sight glass into my freshly-polished clutch cover and got ready to bolt it on with new allen bolts. I also changed the oil yet again, and replaced the oil filter and it's o-ring.

Looking good!

Tuesday, January 22, 2008

Engine Cover refinishing

I removed the clutch actuating shaft, bearing and seal from the clutch housing and knocked out the sight glass. The glass was nice, but I didn't think it (or its rubber seal) would survive the polishing process.

The stator came out with a good hit from the impact driver - the screws showed signs of being replaced before, so maybe this isn't the original stator. I stripped off the remaining factory clearcoat from all three covers to make the polishing easier, and I carefully removed the black circular emblem from the stator cover.

As for the cover refinishing, I'll admit I cheated. While I'd like to say that I spent two days polishing the covers by hand, I can't. I took them to a polishing shop near my work and gave the guy $60. I figure that's a small price to pay for the hours and hours I would spend sanding and polishing if I did it myself. He didn't do the best job on them, but good enough for a rider.

I placed a new order for sidecover gaskets, a starter cover, sight glass, clutch shaft seal, and I scoured ebay for some cam caps that are nicer than my pitted originals. I also ordered a set of stainless allen bolts for all the covers from eBay. Many of the stock Suzuki bolts were rusty and corroded, and some were stripped out from previous attempts at removal. My experience has been that OEM Japanese screws are horribly soft and strip when looked at with a screwdriver.

Allen bolts may not be perfect, but they work really well for low-torque applications like the valve cover and engine case covers. I already had stainless intake bolts from my oring kit, but now I had them for the rest of the motor. At $35 they're not too expensive, either.

Now to tackle that clutch...

Wednesday, January 16, 2008

Valve Adjustment

Before I yanked off the valve cover and started working inside the engine to replace the tach drive parts I pulled the spark plugs and tested the compression. If it was still low I'd be doing a top end rebuild instead of a valve adjustment so this was the perfect time to check it out. Plugs looked fine, but maybe a little white (lean). I'll do some more plug cuts to verify later.

Compression test came back 145-140-145-145.

Awesome. The bores and rings are still good.

Once the tach seal challenge was overcome, I checked the valves. On the exhaust side, there was one tight valve and one very loose one. The shims were 2.85-2.95-2.85-2.90, with the 2.85 on the loose valve and the 2.95 on the tight valve. I swapped the 2.85 and 2.95 and was rewarded with perfect valve adjustment on all four.

On the intake side, again there was one slightly loose valve and three that were perfect. Shims were 2.75-2.75-2.75-2.70. I ordered the requisite 2.80 shim to replace the loose valve's 2.75. Not bad for an unknown engine that has been sitting for 27 years.

While I had the valve cover off I refinished it with silver engine paint. I also scrubbed the cases and cylinder with solvent to give the motor even more sparkle.

The problem with this was it made the scruffy finish on the sidecovers stand out even more. The bike wasn't going anywhere for a while, so it made sense to pull them off, and there was the issue of the weak charging and rattling clutch, and of course I had to change the engine oil to flush out the dirt from having the valve cover off and my grubby hands inside the motor.

Before I could help myself I had out my impact driver and had drained the oil. I removed the clutch cover and stator cover, disconnecting the stator in the process. I also pulled off the chrome starter cover and sprocket cover.

To be continued...

Monday, January 14, 2008

Petcock Reprise, Tach Seal

Well, I've put about 60 miles on the bike since getting it running, and it's a sweet runner. The carbs required only a little tweaking to get it down to a sweet, smooth idle, and it fires off on the first button push every morning. The brakes are hard as bricks and a delight to use, and the refreshed suspension gives the bike good behavior over bumpy surfaces with no head shake up to the speed I chickened out at - 115 according to the speedo. It got there mighty quick - this thing has tons of power. It's also enough to cruise in comfort at 80 mph on our LA freeways. The transmission shifts nicely after I adjusted the shift lever down one spline on the shaft to match my boot better.

So what's the catch? Well, there are a couple of small issues that I will have to deal with:

- A slight oil leak at the tach drive, and another at the valve cover gasket. Both dripped oil on the exhaust leaving me with a nice oil cloud at long stop lights.
- A gas smell emanating from the bike. Seemed to be coming from the carbs, which were damp on the bottom. This only appeared after parking.
- A couple of cosmetic issues that I want to deal with, including the caps at the end of the cams, the engine side covers and the chrome starter cover.
- The charging system or battery might be a little weak - at stoplights the lights dim slightly until the revs get back above 2000-3000.
- The clutch rattles (another common GS problem) but that might be solved with a carb balance.

Curiosity got the better of me, and a few days ago I decided to deal with the carb issue. A wet drain tube from one of the center carbs pointed to a leaky petcock. I was a little irritated by this because I had just replaced all the seals. One bolt sets the tank free, and with it on the bench I watched the outlet for a few seconds to verify that it was dripping slowly. I tipped the tank over and disassembled the valve portion of the petcock. Everything appeared to be fine, but there was a tiny bit of corrosion on the back of the valve lever. I sanded it on a piece of glass with 800 grit sandpaper until all traces of pitting were gone.

Back together it still leaked, which meant the problem was with the diaphragm. I pulled the back apart and sure enough, the o-ring on the diaphragm valve was cracked. Damn - Suzuki doesn't see fit to sell it separately, and I was starting to regret not just buying a new petcock. I grudgingly placed an order with Z1 enterprises for a new diaphragm. I always regret buying aftermarket parts, and this time was no exception. The diaphragm that arrived had an o-ring that was too small for the recess in the petcock. Why do I bother? I'll live with the seepage for now, but I will be buying a new petcock soon.

While I had the tank off I decided to reseal the tach drive and valve cover too, and do a valve adjustment. I removed the bolt and cable and started to gently pry the drive housing out of the head. Before I knew what happened, the housing broke off flush with the head surface.


For better or worse I was tearing into this thing. I pulled the valve cover and tried to pry the stub of remaining tach drive out of the head. It wouldn't budge, obviously stuck in place with 30 years worth of aluminum corrosion. Damn, damn damn.

The next step would be to pull the cam but I was able to avoid it with a pair of vice grips, pick, punch and hammer. The carnage took out the gear, too, so it looked like I'd be buying more parts than I anticipated. With the valve cover off while I wait for parts, I figure it's as good a time as any to take care of all the engine issues that I still had.

Thursday, January 10, 2008


When I bought the GS1000, it had not been registered since 1981. It had a CA plate, but the owner didn't have the original title. Back in the 80s this wasn't that uncommon. If you had a bike in the 80s (and into the early '90s) that you weren't riding, you didn't have to pay the registration. When you went to re-register it, you just had to do a form called a 'non-op' and state that it hadn't been on the road in X number of years. With that out of the way, all that was due was current registration charges.

Sometime in the 90s that changed. Now, you have to apply for a non-op BEFORE the registration lapses. If you don get one, late fees and additional penalties add up very quickly, with each year's registration charges added to the previous year's. An old bike can run up more than its market value in back fees and penalties after just a couple of years.

Anyway, after 7 years all that is moot, since the DMV purges records after that long. Basically you just tell the DMV that it hasn't been registered or driven and the clock starts from zero. Technically the current owner is liable for back fees, but since they have no record of who the 'real' owner is, there's a lot of room to avoid them.

With a lot of luck and "shopping" DMV and AAA offices for the most inattentive/lax counter workers, I was able to get the bike registered with a minimum of cost and complication. I did have to visit four offices, but hey, it only cost me $56.00 in the end, and I didn't have to visit the CHP for a vehicle verification.

I felt like I won the lottery when the nice lady at the DMV handed over my new plate. Unfortunately during this "resetting" process the DMV makes you surrender your old plates - the GS1000 lost its original blue and yellow one. There's probably a way around that, but I don't know it.

Sunday, January 6, 2008

A Few Modifications

I bought a couple of parts with the bike including a K&N drop-in filter and an aftermarket oil cooler (the progressive springs in the picture I installed when I rebuilt the forks). Since I just got it running, and it wasn't registered yet I figured I would install them now.

The cooler was was made by Derale, and was the same vintage as the bike. These air-cooled engines run really hot, so a cooler is always a good idea. It adds to the vintage "muscle bike" look and feel, too. Yeah, I know I could probably sell it for $100 on eBay but I like the idea of using parts that the original owner collected for this bike.

Most aftermarket coolers use an oil distribution block that replaces the oil pressure sender block on the back of the engine. The Derale cooler, on the other hand, came with a neat drill template used to drill and tap the stock sender block for a hose fitting. Maybe not as trick as the other solution, the drilled stock block seemed like a good idea and I decided to go ahead with it.

The return line for the Derale cooler is plumbed back to the oil filter housing drain bolt. This side was a piece of cake to hook up.

The cooler itself came with a simple flat bracket for mounting; I mounted it according to the instructions and it's not the most trick setup but it works.

I ran the lines along the outside of the motor since I was too lazy to pull the tank. The tank's going to have to come off for the valve adjustment and carb sync, so I will have another opportunity to do something about it later.

Wednesday, January 2, 2008


After I got the tank, forks and exhaust back on the bike, I really didn't have an excuse not to start it up. The day of reckoning had come.

First I drained out the old oil and re-filled the crankcase with 10w40 Valvoline motorcycle oil. This would flush out the remaining ATF that I filled the cylinders with, and remove any contaminants that had managed to find their way into the crankcase over the years.

Next I filled my gas can with a couple of gallons of 91 octane CA gas and threw a bit into the tank. I didn't want the tank to be too heavy if I had to remove it later. I turned the petcock to "prime" and let some fuel trickle into the float bowls, then turned it to "RES".

The battery was one that originally came in my CB450, so it's a little undersized but works pretty well. I had it on a charger while I was working on the bike over the last couple of months, so it was ready to go.

At first the bike simply did not want to start. Repeated cranking didn't do anything, probably because of the stuck rings and low compression. I sprayed some carb cleaner into the intake and was rewarded with some pops and clouds of blue smoke.

After a few minutes of this, the bike started up; snarling and grumbling, but running. I let it warm up, and restarted it a couple of times when it stalled.

With a bit of adjustment on the idle knob, it settled into a high, though unsteady idle. I couldn't resist taking it for a ride like this, and before I knew what was happening I jumped on the seat, dropped it into first and headed around the block.

It ran pretty good, though with some stumbling that I attributed to the carbs not being synced or tuned for the bike. I gladly parked it back in the garage and attended to the final details. It still needs a tuneup, valve and carb adjustment, and I need to check the compression again to see if it's improved, but at least it runs!

Tuesday, January 1, 2008


Happy New Year Everyone! Lots more happening on the bike with all my time off this week. Now it's time to make it look nice!

This bike sat in a covered garage for the last 27 years, but that didn't spare it from the effects of corrosion. Unfortunately, the salt air in areas near the coast (like Torrance, where it lived) tends to attack exposed metal and make it get dull and rusty. All the chrome parts had a thick coating of rust on them when I brought the bike home, and all the alloy was dull. I'm not doing a full, show-style restoration here, but I am trying to make the bike look like the clean survivor that it is. The goal is to have a bike that looks really good, even up close, but still shows the character that only age and careful use can bring.

Some parts, like the gauge pods, mirrors and controls, I was able to clean up with some fine steel wool and chrome polish (and a lot of scrubbing). The chrome on these parts is nice enough for a rider, but not perfect. The alloy engine cases look better after a good bit of scrubbing and polishing, but they will have to come off to become perfect, and the starter cover is beyond salvage. None of this stuff will hold me back from getting the bike on the road, but I hope to have them fixed in the future.

A few other parts were too rusty to use, including the fork tubes (since their surface is not just cosmetic), the front fender, rear turn signals and rear grab handle. The front turn signals, passenger handle and headlight rim are marginal - I'd like to fix them if I find some reasonably priced replacements. The cleaned and polished exhaust will work for now, but ideally I will replace it with an aftermarket pipe for that "superbike" vibe.

I managed to score a nice center stand grab handle, rear turn signals and handlebar pad (the original turned up missing when the bike got home) from Kurt on The GS Resources. These parts really helped out the cosmetics.

The front fender I painted black, which will look nice with the rest of the bike. I sanded the bad chrome with 180 and 320 grit paper and then gave it a quick hit with etching primer in the can. I laid down two coats of black paint and three of clear over that. I like Duplicolor lacquer for this because it's easy to sand between coats and it dries pretty hard.

As for the paint on the tank and seat panel, I got out my favorite Meguire's products - Scratch-X, polish and wax. I gave each panel a thorough polish and wax, finishing off with a microfiber cloth. No, they're not perfect but they are much better than they were, and plenty good enough for a "rider" like this bike. The side panels are nice, though the emblems don't match, and they cleaned up very nicely with soap and water. I bought new screws from Suzuki, as well as new rubber pads for the mounting brackets on the frame.

The seat upholstery looks almost new after a thorough cleaning.

I replaced a couple of chrome dome nuts on the upper triple clamp because they were rusty - I ordered them through Suzuki, and though they aren't exactly the same as stock (go figure!), they will work in a pinch.