Tuesday, November 27, 2007

Rear Brakes

The rear brake system was completely rotted out on the bike when I got it - the master cylinder had leaked out all of the brake fluid, the caliper was seized and the pads were worn almost to the backing plate. in addition, the rear brake line was suspect simply because of its age. (The shop manual recommends replacement every 2 years!)

I removed the entire system and stripped it down for a rebuild. The master cylinder looked OK, there was some tiny pitting on the inside of the bore, but a little scotchbrite cleaned it right up. The piston and seals would be replaced with a rebuild kit, so it didn't matter what condition they were in.

One side of the rear caliper came apart easily, but the other piston was stuck in its bore. Normally I would use compressed air to blow it out of the caliper body, but since I don't have a compressor at home I used a pair of Channelocks. it's a brute-force way to do it, and can cause damage to the piston if you're not careful so I don't normally recommend it.

Both pistons had very minor pitting - not enough to reject them. With new seals this caliper should work nicely, with no leaks or sticking problems.

I ordered the parts to rebuild the system from Motostiles in Lawndale. They were very helpful, but I later learned that OEM parts from a mail-order Suzuki dealer would have been cheaper.

The rear brake hose is a $35 part from Suzuki, so i brought the original down to Earl's in Lawndale, near where I work, and had them make up a replacement in stainless braided teflon hose. I've gone this route on most projects I've done, and I'm always happy with the results. At $36, it was no more expensive than the overpriced original, and should last much longer.

I assembled the brake system onto the bike and did a little cleaning in preparation for installing the new rear tire and wheel.

Wednesday, November 21, 2007

Engine Evaluation

Just for kicks I tried to start the engine when I first got the bike home, but even then I didn't have much hope for it starting. Of course it didn't. I pulled the plugs and found there was only a very weak spark. The plugs were also very well corroded into the head; I used lots of PB Blaster to get them loose so I didn't strip out the threads.

Once I had the plugs out I pulled off the points cover to check their condition. I sprayed a little contact cleaner onto them and ran a business card through the gap. No improvement. What I did notice, however, was the spark that blew across each point gap as it opened. This indicated that the condensors are bad. I didn't bother checking for voltage at the coils, which would be the next step, since I had several other things to attend to.

In the meantime, I spoke to the original owner of the bike. He's a really cool old guy who would still be riding if he hadn't taken a bad fall in the early 1980s. Turns out he has a small stash of new parts for the bike - coils, filters, points plate and a set of 29mm Mikuni smoothbore carbs. I will probably be buying them from him in the next week, since it will save me time and money versus restoring the stock carbs and buying new points.

Back to the engine: I removed the stock carburetors, since there is no point trying to get it to run without giving them a thorough cleaning. Sitting around for 25 years with fuel in them is the worst possible thing that can happen, since the dried out fuel will leave all kinds of nasty deposits inside each one.

I also removed the intake manifolds to give them a thorough inspection - behind each one is an o-ring that hardens and breaks over the years. Vacuum leaks here will cause poor running that will be hard to diagnose later. Removing the stock screws was a bit of a challenge - I used an impact driver on the outer two screws, but the remaining ones did not allow enough space to swing a hammer. I used the bit from the impact drive alone - a good whack of the ball-peen loosened them right up.

An inspection revealed that of course two of the orings were broken. The other two were so hard they were not acting as gaskets any longer. The manifolds themselves appeared in decent condition. No cracks, and the rubber was still flexible. The bond between the rubber and steel flange was loose around the outside edge of a couple of them, but the inside of the flange was still tightly bonded. They should work fine.

With the plugs out and carbs off, I attached a compression tester to each cylinder in turn. I cranked the engine over until the gauge did not increase. Ideal compression for an old 4-cylinder like this is in the 180psi range. The dry old cylinders only managed between 60 and 90 psi. Not good, but hopefully it was caused by stuck rings. First round: 90-80-60-60. I filled each cylinder with automatic transmission fluid to clear out the rings, and let it soak in.

I'll check the compression again after a few days; hopefully the ATF will loosen up the rings and compression will shoot back up. If it does not increase I'll still leave it for a while - the rings may loosen up after the engine runs for a little while. Only after I've put a few 100 miles on the bike will I worry about low compression.

So now that the carbs and engine had been inspected, I made an assessment of the engine condition for future work:

Engine Issues
- Carbs crusty and dirty
- Manifold o-rings broken
- Manifold hardware corroded and damaged
- Low compression
- Minimal spark; arcing across points
- Case outer covers corroded and dull
- Starter cover rusty
- Cam covers rusty
- Missing air filter
- Oil old and unknown condition

Monday, November 19, 2007


After I got the bike into the garage I immediately removed the tank (one bolt at the rear, fuel gauge wires, vac. and fuel lines) and seat (two hitch pins in the hinges). This made it easier to see every detail of the frame and engine for a full diagnosis.

I started at the front of the bike, cataloging every issue that would have to be dealt with before the project is finished, no matter how big or small. The list is not final yet, but here's a start:

Front End
- tire old and hard
- wheel lightly corroded
- fender heavily corroded
- fork tubes heavily corroded
- fork seals cracked
- brake lines cracked
- gauge backs lightly corroded
- switches, fork area dirty
- headlight rim heavily corroded
- top nut and misc. hardware corroded
- levers and hardware lightly corroded
- missing cushion over handlebar clamps

Tank, Seat, Airbox, Sidecovers, Wiring
- tank rusty inside
- petcock frozen in "ON" and leaky
- one dent in tank
- grab rail corroded
- rearstand handle corroded
- missing airbox and sidecover harware
- paint dull in general
- mis-matched sidecover
- all four turn signals in poor, corroded shape
- electrical panel lightly corroded; contacts corroded
- exhaust looks like crap - totally rusty

Frame/Rear Suspension
- minor scratches/chips in frame paint
- rear brake MC leaks
- rear wheel lightly corroded
- rear brake pedal lightly corroded
- some hardware corroded
- rear tire old and hard
- chain dry; unknown condition

Engine evaluation requires a bit more work, so I'll get to that next time.

Friday, November 16, 2007

Getting Home

So I finally got the bike into my garage and started working on it. With the help of a friendly relative with a truck (thanks Vic!) I got it loaded. The trip home was uneventful.

Once home I immediately gave the bike a thorough cleaning with simple green and a hose. I removed the air cleaner housing and side panels to make this easier.

A quick inspection showed it to be just as I had thought - good solid paint, but the chrome and alloy had been attacked by the salty air in Torrance. Some parts, like the brake and shift pedals, levers and wheels will be easy to clean and make look nice again. Others, like the engine side covers, will have to be professionally polished or replaced. The forks and front fender are probably too bad to salvage - I will likely either paint the front fender or replace it with a better one.

The side panel badges are mismatched, which I didn't notice before, but it should not be hard to find a pair on ebay.

I couldn't resist the urge to install a battery that I had laying around - it is slightly smaller than the stock battery but should have enough power to start the bike. I checked oil, threw in a few ounces of fresh gas and hit the thumb button. It cranked over (indicating that the engine is not seized), but didn't start. I opened a couple of the carb drain plugs and found that the engine was definitely getting fuel, or at least enough to cough. I pulled a plug and the reason for the non-starting was quickly apparent - a weak spark that could barely bridge the stock gap showed that something was wrong with the ignition system. I planned to rebuild the carbs and tank before getting serious about starting it, so I gave up and rolled it into the garage.

To Be Continued...

Wednesday, November 14, 2007

The Search and The Deal

I've been checking all the usual suspects the last couple of weeks - Craigslist, eBay, etc.

Finally I found an ad on Craigslist for two 1978 GS1000s in Torrance - the ad said they had been sitting since 1982. Seller wanted $400 each, which seemed fair.

When I went to check out the bikes they were pretty much as advertised. One was nearly 100% complete, the other was missing turn signals, grab rail and had an aftermarket seat. Apparently it was originally fitted with a Vetter fairing (also included). Both had rusty chrome and corroded alloy, but nothing looked too serious. The paint on both looked like they had been stored inside as claimed, but of course the tanks were rusty inside.

Ultimately I bought the better one of the pair - the second bike was just missing a few too many parts and the seller wasn't willing to deal. I may buy it later if we can work something out.

It's a 1978 GS1000 "E" model with cast alloy wheels and triple disc brakes. It differs from other pictures I've seen in not having the "skunk" white stripe, and having black lower fork legs. Odd, but apparently some came that way.

Here are some pictures that the seller took:

Tuesday, November 13, 2007

A little background

This whole thing came about because I am nearing the completion of a Honda CB450 vintage race replica project that I've been working on for the past year and a half. It's a fun little bike, but not serious, and somewhat small.

This is what it started out like:

In a nutshell, it's a 1971 CL450 with a "black bomber" chrome tank from an early model CB450. Rattle-can frame & tank (paint sux on it, though). Full list of mods:

- CB750f 35mm forks; cut springs, modified valving, fork brace, custom axle spacer
- CB500t triple clamps, polished & clamps removed
- Honda-repro levers & stock RH switch
- Dunstall-replica clip ons & Ceriani-replica headlight brackets; stock headlight & tach
- cleaned up wiring harness
- Airtech seat, custom upholstery
- 1967 CB450 tank; bad paint & mediocre chrome
- Cut & painted rear fender; 'glass front fender from ebay; lightweight alloy rear light & license bracket
- removed side covers, battery box, center stand and unneeded brackets (ctr. stand brackets remain)
- custom battery box for AGM battery
- GSXR rearsets; brackets polished, custom linkage, rear brake cable conversion
- NOS S&W rear shocks, 1" longer than stock
- Rebuilt engine; ported head, Cappellini race rollers, new valves, Kibblewhite guides, polished cases, CB550f kick starter, custom 73mm JE pistons; velocity stacks
- Soon to come: billet rear brake stay, better cable anchor, 2:1 exhaust

The GS1000 will be a natural progression of this project - I did so many mods to the CB450 that it isn't really the same bike any more. I want the GS1000 to be all stock, tempting as it may be to modify it.

Monday, November 12, 2007

Why GS1000?

Recently I thought it would be fun to find an old "big bike" to fix up and make look nice. Not really a 'restoration' per se, but more of a 'refresh'. I wanted to find something that was common enough to be easy to restore and inexpensive enough that I could afford to buy a fixer. Also something with style, and a little flash. Thousands of various so-called UJMs were made in the 70s and 80s, but 90% were ridden into the ground because they're so durable, especially out here in California.

I thought of SOHC CB750s, which are really popular right now, but they're just a little too lo-tech and common for me. The DOHC CB750 is a cool bike, too, but I don't see them for sale in fixable condition very often. Forget the Kawasaki Z900 and Z1000 - those are too in demand in Japan, where they're seen in somewhat the same nostalgic light as muscle cars are here in the states. Even a basket "zed" can run $1500 or more. Neat, but not really what I was looking for.

Of the remaining big bikes, Honda GL1000 Goldwings are cool, but most have terminal mileage and something about the shaft drive turns me off. Too old man, maybe. Skipping right over the forgettable (and ugly) Yamaha XS750 and 1100, the most likely candidate was the Suzuki GS750/1000.

So the search was on. My requirements:

- Cheap. I'm not a rich guy, and so it had to be inexpensive. I also know how expensive these projects can be, so it's important to start right and keep the budget low from the beginning. I assume the tires are going to be bad on an old bike, and probably the chain, tank, carbs, etc. About $400-500 before I can even start on the cosmetics. Also, I'm looking for a bike that only sells for $2500 in perfect condition, so there isn't much of a margin if I hope to come out ahead of just buying a good one.

- Complete. It's a serious PITA to track down parts for some of these bikes, so the more parts the better. Particularly trim (side panels, seat, etc.)

- Cosmetically pretty good, not perfect. I don't mind a little crust, dust and possibly rust. No massive dents. Original paint that could be salvaged would be nice, and good chrome too. Japanese chrome and polished alloy from the 1970s tends to go off pretty quick.