SR500 Project

Got my front end back...

2011-03-20T18:54:00.000-07:00

My dad brought my front end to me. He kept it to finish the headlight mount, rotor spacer, and caliper bracket.

Rotor spacer

The wheel weights are a temp job until I get some better ones. These just let me know how much and where to put the nice ones.

Front end

Caliper bracket. Still needs to be polished, and may have some more machine work done later. I want to put it on and figure out if I want to drill holes in it or something to fancy it up.

Stripped frame

2011-03-19T13:29:00.000-07:00

After dealing with one powder coater who did a shitty job on my wheels, and another one who flaked out on me, I have decided to just paint the frame myself. Apparently Austin has everything except a decent powder coater. Oh well...I got the frame stripped. I need to do some final sanding on it, then I'll primer it next weekend.

Plating metal parts

2011-03-12T16:09:00.000-08:00

Instead of using a commercial plater, I decided to plate my few metal parts that I'm reusing myself. I bought a tin-zinc plating kit from Eastwood, http://www.eastwood.com/ew-electroplating-system-tin-zinc.html the kit has worked great.

4 parts on the right have been plated, the rest are raw.

Parts I've plated so far. I have more to do, but this was the first batch. I'm very happy with the finish. It's a nice shiny silver.

New tank

2011-03-03T15:13:00.000-08:00

Same size/shape as the one I bought before, but it had a rusty bottom. It was cheaper to buy a new tank off ebay than to have the bottom replaced on the other one. I like the paint scheme on this one.

Front end

2011-02-23T16:18:00.000-08:00

I left this in Indiana for my dad to finish up. I'll get it in a month or so. It looks awesome so far.

Spacer that my dad machined to replace the speedometer gear/housing. No speedometer will be used, so instead of just having a gear with no cable, this piece was made; it is aluminum with a steel insert. He is also making a spacer to move the rotor out 1/4" and a bracket to mount the caliper.

Exhaust bracket / brake stop and electronics plate

2011-02-23T16:11:00.000-08:00

I need to chop off part of the original brake stop still.

More pictures of my dad's shop

2011-02-23T16:09:00.000-08:00

Mounting exhaust bracket that I forgot to take a picture of...

2011-02-20T16:46:00.000-08:00

Fender, seat, and electronics panel mounts

2011-02-20T16:35:00.000-08:00

2011-02-20T16:32:00.000-08:00

We put in a new bung for the oil tank. The stock bung and filler cap were too tall. The tank will be mounted over the oil cap.

We added a round cap on the rear of the frame where it was cut to finish off the back end.

Arrived in Indiana to do work at my dad's shop...

2011-02-20T16:26:00.000-08:00

A nice view of 2 Indians...

Indian Scout

1942 Indian 442

Another Indian

Ariel Square Four

1954 Harley anniversary edition, my great uncle Harold's bike.

Dyno Room

Some aluminum polishing done...

2011-02-14T18:39:00.000-08:00

Polished the kick indicator and the fork legs. I am not sure what all will be polished yet. I leave for Indiana in 3 days. Many updates soon.

Tires arrived

2011-01-05T14:50:00.000-08:00

4.00-19 and 4.50-18 Firestone Deluxe Champion from Coker Tire.

Just a few more things to do before I head to my dad's shop in Indiana in February. I need to get my wheels powder coated and have some chrome removed from a few pieces, and polish some aluminum. The engine will also be torn apart this weekend.

Brembo caliper arrived...

2010-12-20T15:33:00.000-08:00

It was hard to find a silver one, but I ended up finding a set for $99 on ebay because the right caliper was damaged. I only need a left one, so I got a steal. The caliper is off a 2005 Victory Hammer.

Tanks side by side

2010-12-17T13:47:00.000-08:00

Stock SR500 tank next to the GT80 tank

Tank fits on now

2010-12-17T13:30:00.000-08:00

More grinding

2010-12-17T13:27:00.000-08:00

Did some grinding and sanding today. Removed the old tank mounts and the coil mount. I'm going to use a much smaller Nology coil.

I'll need to use a die grinder to get the rest of the mount ground off.

New rotor and controls

2010-12-16T15:40:00.000-08:00

Off of a 94 Yamaha YZF750, old heavy rotor is on the right.

Controls are off of an 08 Honda CRF230, but are brand new. I wanted to go with dirtbike controls for a hot start lever that I can use for my decompression lever; also there will be no empty holes where the mirrors are supposed to go. I will use a bar end mirror on the left side. The Honda CRF230 also has a street legal version, so I was able to get a banjo bolt with a pressure switch that will fit with no trial/error for my brake light. I also wanted an aluminum master cylinder.

New caliper should show up soon...

New tank

2010-12-13T18:41:00.000-08:00

From a mid-70's Yamaha GT80. No dents or dings. $40 bucks off of ebay. I will need to chop the factory tank mounts off the frame.

I just had to trim the inner mounts to get it to fit over the oil tank.

Forks taken apart

2010-11-22T18:10:00.000-08:00

The forks were a pain in the ass to take apart. With or without spring compression, the dampening rods spin without something inside to hold it in place.

Luckily, I found online it was 17mm inside. I JB Welded a 17mm nut to some allthread.

And this worked to hold the rod in place to get the forks apart.

The fork tubes were dirty and had minor surface rust, but no pits.

They cleaned up as good as new.

Now to ship these to Indiana and have the circled tabs removed via lathe.

Grinding is done

2010-11-14T11:45:00.000-08:00

Before:

After:

Next I'll have to sand it all smooth. I took off the brake stop with the rear footpeg mount. A new and improved brake stop/muffler bracket will need to be made.

Parts removed:

Every rear bracket that wasn't an engine mount is gone. The back end was chopped off. The center stand mounts and factory header mount were removed from the bottom. The rear foot peg mounts and the air cleaner cover mounts were removed. 5 hours and 2 cutting, 2 grinding, and 2 sanding discs were used.

Ready for the grinder

2010-11-11T12:53:00.000-08:00

Old ad

2010-11-07T00:09:00.000-07:00

click to read

Wikipedia stuff....a really good read about the Yamaha 500

2010-11-06T21:41:00.000-07:00

History

Released in 1978, the SR500 was Yamaha’s attempt to cash in on nostalgia for the period when 500 singles were the preferred mount of serious riders. The SR500 eventually led to the SRX600 and Yamaha now produces a 660 road single. Although, the reputation of the SR500 remains so strong, that Yamaha has continued to produce it (ending in 2008) both for the Japanese domestic market (in 400cc form to take advantage of registration laws) and for the European market where its popularity has never diminished.
The roaring seventies saw a breathtaking development: faster, bigger and heavier, the motorcycle world seemed to turn around. The dream was made of multi-cylinders with constantly increasing horse power. It was a fascinating development and most manufacturers did everything to boost this mainstream fashion, when Yamaha turned around and seemed to go backwards. Forgotten were the times in the sixties where big singles touched the heart of enthusiasts. The famous British 4-stroke singles, such as Norton, Velocette, or BSA had died, smoother and faster bikes, replaced them. They were less vibrating and so much easier to ride and the breed of big thumpers seemed to share the fate of the good old dinosaurs. No wonder the world was kind of shocked when the forgotten came back: the XT 500 brought back the steam hammer sound of a big single four stoke- and the world was prepared to listen.

Engineering was reluctant at first

Shiro Nakamura (later also responsible for XS 750 triple, XS 400 twin, XS 1100 four and the SR 500) who developed the XT engine remembers: "When the off road market started booming in the US, bikers remembered the advantages of the good old singles. Soon the sales guys started to request the development of a four stroke for off road. Honestly speaking, we engineers were quite reluctant in the beginning, since we knew about the difficulties of these big thumpers. As soon as they had a bit more power they turned out to be unreliable and they were shaking like hell."
Nakamura-san continues, "Now I can confess that developing this first big single was a real nightmare. It was only the second four-stroke designed by Yamaha. We tested many different configurations including DOHC and even cylinder head oil cooling, but the XT was supposed to be simple and reliable and we turned away from all these complicated solutions.

Many technical problems to be solved

First, the heavy pistons gave us countless problems. They seized up and were punched. Cylinder and head development was as difficult. We even had a cylinder that broke in the middle. At that time we didn't even try balancer systems, although we had many problems with broken crankshaft bearings as well. The con-rod had no big end bearing but was turning on a needle bearing that needed a low pressure lubrication. We did make this choice instead of using a one-piece forged crankshaft with assembled connecting rod because it allowed us to build a much more compact engine and was also cheaper to produce due to its vertically split crankcase. In the end all our technical problems delayed the roll out by more than one year But we had succeeded, XT was now more reliable than a big single 4-stroke had ever been. Although it was over square with a bore and stroke of 87 x 84 mm, (all British bikes were long stroke) we obtained the real character of a big thumper. The two-valve head gave a flat torque curve while the smaller flywheel allowed the engine to rev up as easily as we wanted. Dry sump and short stroke also allowed for better ground clearance and a more compact engine than former British bikes ever had."

Rollout in 1975 in the US

The first XT 500 was shown at the US dealer convention in September 1975. Europeans had to wait till the summer of 1976 before they could press their boots against the heavy kick-starter.
The XT 500 was an instant success and was produced until 1990. It laid the ground for the later range of XT bikes ranging from 125 cc (XT 125) to 750 (XTZ 750) and contributed largely to Yamaha's image.
The XT proved its performance and reliability by winning the first big African rallies, which were on the rise in the late seventies. It started with Paris-Abidjan-Nice and then the godfather of all rallies, the famous Paris-Dakar, which confirmed the supremacy of the XT 500. In France alone 62,000 XT 500's were sold from 1976 to 1990.

SR 500: the thumper for the open road

Shunji Tanaka's idea from the beginning of the XT project, was to develop a street model on the same engine base for the European market. He faced resistance first from marketing people, who were convinced that the big thumper era on the road was definitely dead. "We will only sell some units" he used to hear. Tanaka believed in his intuition and pushed the SR 500 through for the launch in the Japanese market in 1978. While for the XT the priority had been reliability and simplicity, the keyword for this street model was "easy to use". It explains the major difference between the SR and XT engine: the electronic ignition and a clever new concept to make kick start easier. It was a manual decompressor system.
Nakamura tells the background story: "It came in fact from an accident! Mr. Morinaga, Yamaha Motor's Technical Director, tested the SR prototype and got a wrench to his ankle as he tried to kick it. Easy starting then instantly became a first priority!"

British design influence

The SR 500 was designed by Atsushi Ishiyama, today President of GK dynamics. He worked on the very first Yamaha and contributed a lot to create Yamaha's reputation in design. He says: "Our choice was to design the new SR 500 with a strong family image and a strong link to our first four stroke, the XS 650 twin, which was also inspired by British design at first." The SR 500 was going to become a legend as one of most reliable and easy-to-maintain motorcycles ever built. It sold until 1999, with a huge demand in Germany and Japan, until new noise and emission regulations signalled the end for this big air-cooled single.

The XT 500 in the Paris Dakar rally

XT 500 entered desert Rallies in 1976 in the second edition of the first rally of this type organised, the "Paris-Abidjan-Nice" also called "Côte d'Ivoire-Côte d'Azur". Four official XTs were at the start on December 29, 1976. They were completely standard with the exception of a 25 liter fuel tank and a sturdy luggage carrier supporting tools and two 5 litre jerry cans. Aside those machines, engaged by the French importer, were 14 other XTs. It was a fantastic success, a total of 10 XTs finished the hard endurance desert race where Gilles Comte took the victory. For years XT and Paris-Dakar Rally were words that belonged together. In 1979 and 1980, Cyril Neveu won on an XT 500.

Modifications

Commonly an extra oil line is run to the exhaust side of the cylinder head - a design flaw that has been rectified in the later SR400 models. Many SR owners fabricate their own oil lines to both intake and exhauser rockers to ensure proper lubrication.

SR400 Evolution

1978 witnessed the debut of both the SR400-a bike with a super-long reign as a top seller in the mid-range class and that even now maintains a deep-rooted popularity in Japan-and its sister bike, the SR500.
The SR400 was born with the same air-cooled, 4-stroke, overhead cam, 2-valve, single-cylinder engine from the big XT500 off-roader, but with a shortened stroke and refined for road sports use, resulting in a final capacity of 399-cc. Equipped with a decompression lever, dry sump oil lubrication that used a portion of the frame for its tank, and a kick indicator for the kick-start engine, the SR400 started more easily than any single-cylinder motorcycle had up to that point. The front fork, the rims and the brakes were all taken from the TX650 and the tires employed a semi-block pattern for running on dirt, like a flat-tracker.
In 1985, a drum brake was adopted in the front, and the front wheel size was dropped from 19 inches to 18 in order to produce a retro look. Greater reliability was also targeted for the engine through a change in oil lines as well as other parts. From 2001, hydraulic front disc brakes were installed, and the SR400 evolved to a machine that provided even greater enjoyment during acceleration and deceleration than was usual for a sports bike of its age.
Since it is a single-cylinder bike, you'll experience the advantages of the lightweight, compact, slim body as soon as you get on. Not only is it easy to balance at a stop, but Yamaha's return of the footpeg position to that of the initial model, coupled with the repeated improvements made to the seat, were also effective in creating a comfortable riding position with only a slight bending of the knees. The motor is still kick-started. An understanding of the four stroke engine, and careful positioning of the piston just past the top-dead-center position aid in easier starting. All starts use the choke, cold starts benefit by first twisting the throttle a couple times to inject extra gas in the carburetor. The engine should never be started with the throttle in the open position due to the chance of dangerous kick-back.
Handling displays a calm, straightforward character from beginning to end, and the engine also doesn't necessarily value response over all else. Rather than winding all the way up to high revs, shift up a little bit early and you'll experience a smoother ride while enjoying the beat of the engine and the surrounding scenery. That's the kind of relaxed running that's most suitable for the gorgeous SR400.

More progress

2010-11-06T11:25:00.000-07:00

I wanted to remove all electrical components and the carburetor today.

As it sits today.

I'll take the engine out next weekend.

Ordered stuff

2010-11-03T17:18:00.000-07:00

$59.83 - 6" flat rear fender

$22.75 - polished stainless bolt kit for the engine

$155.13 - stainless header from Thailand (Motolanna)

$117.01 - new petcock for non vacuum carb, fork seals, dust covers, a few other seals, and foot peg rubbers

$59.99 - muffler

$8.99 - muffler baffle

$51.90 - complete gasket kit

$141.00 - Nology coil, wire, spark plug

$1,500 for the bike + 616.60 = $2116.60

$1883.40 left in my 4k budget.

Disassembly

2010-10-31T11:07:00.000-07:00

Back end stripped down:

Gas tank, headlight, and turn signals removed. Fork tubes aren't as bad as I thought. I think they can be salvaged. The gas tank was spotless inside and had minimal surface rust underneath.

The oil in frame is very cool.

Small workspace

2010-10-31T10:57:00.000-07:00

I don't have a whole lot of extra room; the project is being done in an 8'x8' storage shed.

Since I'm limited on space, instead of buying a normal motorcycle stand, I got this Snap-On toolbox for $100 off of Craigslist. It's old and beat up, but all the drawers work, and it's built like a tank. After the wheels/tires come off, the motorcycle will go on top of the box, and then the drawers will be used to store nuts/bolts/small parts.

SR500

2010-10-31T07:44:00.000-07:00

1981 Yamaha SR500.

Purchased for $1,500.

2,037 miles on the odometer.

The bike has no spark and does not currently run. Everything will be replaced or rebuilt, so I did not care if it ran or not.

2 previous owners. 2nd owner purchased the bike in 1994 with 750 miles on it from the original Yamaha dealership it was sent to in 1981; it was never sold. The seller said the owner of the Yamaha shop had kept this bike there as one of his personal bikes.

Years produced: 1978-81
Total production: 15,000 (est.)
Claimed power: 33hp @ 6,500rpm
Top speed: 96mph
Engine type: Overhead cam, air-cooled single
Weight (dry): 353lb
Price: $1,898 (1980)
MPG: 45-60

1978 and 1979 had a rear disc brake, 1980 and 1981 had a rear drum. The drum brake makes for a cleaner look and no rear master cylinder, so I wanted an 80 or 81 for that reason.

The bike was purchased in Nacogdoches, TX, which is roughly 5 hours from Austin.