Refurbishing a 1980 Yamaha SR500

rebelrider.mike

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May 25, 2017
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Hi folks,
I know some of you enjoy motorcycles, so I thought I'd share this. I had a 1980 Yamaha SR500 gifted to me after sitting for 10 years as a non-runner. Couldn't refuse such an opportunity.

I'm not familiar with Yamaha's at all so this is a learning project. Also, I've been wanting to learn more about fixing my own bikes. This will definitely help with that!

The original problem was that no spark was getting to the spark plug. Now though, it's got lots of secondary issues from sitting.

This all started about a year and a half ago, and is a big reason why I've not worked on the DIY ebike for quite a while.
 

rebelrider.mike

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Parts 3 and 4:

Early on I decided that the priority should be getting spark back, which was the original problem. But while waiting for parts to come in the mail, I decided to work on other stuff too. Starting with some of the electrical I could fix for free, and also getting into the carburetor, which turned out to be a whole project by itself.
 

rebelrider.mike

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In these vids, I finished disassembling the carburetor, and decided to repair the engine kill switch. Unfortunately, I started having audio problems. You can here stuff, but it sounds like it's underwater.
 

rebelrider.mike

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Cleaned up the fuel valve, and got into the speedometer after discovering it was seized. Still having intermittent audio issues.
 

rebelrider.mike

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Cleaning up gauges and switches. Cleaning contacts. Discovering just how bad the seat is.
 

rebelrider.mike

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Finishing up the seat. (For now.) Looking for any other issues on the bike. Got severalparts in the mail.
 

rebelrider.mike

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More work on the carburetor. I don't know if this is interesting or not. But it's part of the series, so there it is.
 

rebelrider.mike

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Took the front brake system apart. Everything seized, and nothing but water inside!
Some good news though. First time the engine has run in over a decade!
 

rebelrider.mike

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Rebuilding the master cylinder, and the muffler. Changed the oil, and cleaned the oil strainers. More tinkering with the carburetor.
 

rebelrider.mike

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Changed the oil, and cleaning the oil strainers. This bike has 2 strainers and a filter. Also cleaned and oiled the air filter.
The muffler got de-rusted, de-chromed. and painted. Parts got an hour in the oven at 200F to cure.
Got a shop manual in the mail. And getting a section of the old drive chain ready to be a new tool.
 

rebelrider.mike

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I was still having carburetor issues at this point. Turns out without the air leak the engine was being flooded. So more carburetor work.
Also found some (and made some) issues with the timing. Things got better later on though.
 

rebelrider.mike

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Did some more miscellaneous stuff on the bike, and started on the rear wheel. I've never taken apart a motorcycle wheel before. My closest experience is on a moped. Which has a lot fewer parts. But I got it apart and cleaned up, and I learned some stuff in the process.
 

rebelrider.mike

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Repaired the broken sensor screw, finished assembling the rear wheel, and got the engine running again. Still didn't run well, but I later discovered that the carburetor was again the issue.
 

rebelrider.mike

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The carburetor has had to come off for tinkering so many times, LOL. Stubborn little guy! I don't think I'll ever want a vehicle with more than one carb. For me at least, simpler is better. Also got some painting done. Got the rear wheel reinstalled. Discovered there's still some work to be done with the front brake. But it's getting really close to going for a test ride!
 

rebelrider.mike

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Got some questions answered, and started working on the interior of the gas tank, and the gas cap. Also stripped the paint off the outside of the tank. I got to use a new boroscope to look at the inside of the tank. I used rocks and tumbling to get the crusty rust out of the tank, and had some trouble getting the last two out.
 

kc8adu

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May 22, 2019
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i have rebuilt a bunch of bikes myself.
got a goldwing tore down right now.
getting that tank fixed is first.
as long as its shedding crud you wont keep a carb working very long.
i tear the carb down and remove any plastic.
then soak in hydro seal or berrymans carb dip.
blast it out with air then carb cleaner in a aerosol can.
then for good measure it goes in the ultrasonic cleaner a while.
its funny to see the stuff come out of one you thought you had clean!
put an inline filter on it too.
i have seen a few of those yamaha's over the years.
worst issue(besides fuel system neglect) was occasional bad stator and or rectifier/regulator.
 

rebelrider.mike

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Hi Kc8adu!
Yep, this has been a stubborn carburetor for sure! Doesn't help that I was never able to identify it for new parts. It's finally working good though. I was able to get a small ultrasonic cleaner last year. Does a really good job.

The previous owner actually had the stator re-wound. Still no spark though, and that's when it got set aside for 10 years. When I got it all the ohm readings were good on the stator, but the coil was questionable. And it had an aftermarket CDI. I managed to get a good deal on a brand new set made specifically for this bike. I also found that the "new" spark plug was faulty. Fuel, spark and timing are all fixed now. :)

I'm still a bit behind with the videos, so here's a couple more:

I had some more fun with the boroscope after I cleaned up my sealant mess, and let the tank dry for a while. I've also been playing with electroplating nickel. I still have mixed results though, (likely I'm not getting the parts clean enough.)

I've also got the outside of the tank cleaned up and I'm even trying some body work. First time ever. I guess in the video I forgot to say I've also put clear coat on it. In my humble opinion, it all turned out great except the clear coat. For some reason I have a hard time getting it thick enough to be uniform, but not so thick that it runs. But it's a refurbishment, not a restoration, so at least the rust is gone, LOL.

Got all the drive chain stuff done too. Getting really close to a test ride!
 
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