DeadStar Posted June 30, 2009 Share Posted June 30, 2009 Hey, everyone. I just bought a 1976 Yamaha RS100 a couple of days ago. This is my first bike and it is currently not running. I have never worked on bikes before and I was wondering if anyone had any suggestions as to going about learning. Link to comment Share on other sites More sharing options...
DTGordo Posted June 30, 2009 Share Posted June 30, 2009 Hi Deadstar, I'd start by getting a service manual/book for your bike that will provide you with most basic information. Some books are better than others but it comes down to what you can find as well. I got mine off ebay but some librarys have em too (which I found out by accident). You'll probably be replacing bits and pieces for an old bike so find a parts source: motorcycle wreckers and ebay/online sellers seem to turn up bits for most anything over time. You might need some tools particular to the bike too if you plan on doing most of the stuff yourself. As she's not running, I'd be going through the trouble-shooting bits in the manual first and that might get it up and going. Maybe you know someone that has some idea about small engines that might be able to help you and this forum is a good connection to lots of people who know lots and some who know a lot less (like me) but who like stuffing around with old bikes. Most of all enjoy getting your hands dirty and pulling the thing apart and putting it back together. Hope you get out there soon, Gordo Link to comment Share on other sites More sharing options...
Tylerman Posted June 30, 2009 Share Posted June 30, 2009 Welcome, I just went through the process of getting an RS100 back on the road myself. First rule of any gasoline engine, It will run if it has three things: GAS COMPRESSION SPARK Couple questions to start with; -Does the engine turn over? If not, is the kickstarter stuck? In my case the kickstarter was stripped and wouldn't spin, but if I put the bike in gear I could push the bike forward and feel the engine turn. If the engine will not turn that way, well, it likely siezed the piston inside the cylinder and you've got big problems. If the engine is not stuck, buy yourself a compression tester (available at any auto parts store) and do a compression check. Remove the spark plug, crew in the tester, hold open the throttle and kick it over several times. You want at least 110psi after four or five kicks. Anything less than that and you will need to pull the cylinder head and cylinder and see what's wrong inside. It could be as simple as a new set of rings to get it back up to snuff. Do not be alarmed, this sounds daunting but it is very simple on this bike, and can be done with the engine in the frame. Don't go pulling your engine apart yet, though, check the other stuff below. -Do you have a spark? When you take the spark plug out, plug it back into the plug wire and hold it against the cylinder. Turn the key to the center position of the keyswitch, and turn the ignition switch to the run position. Be careful to hold the spark plug wire only, do not touch the spark plug or you could get a shock, and kick the engine over. With the plug grounded against the cylinder you should see a blue spark. It helps to do this in a dark place or at night if you are working outside. If you have a spark, you are in good shape, but if not then remove the cover over the left side of the engine to expose the flywheel. You can look through the windows on the flywheel and see the contact breaker inside, have a friend kick the bike over and look at the breaker (also known as a "point") to see if you have a spark there. If there is a spark, then the problem is between it and the ignition coil. In my case, the coil was bad, I found a good one on eBay for $15. Take the time to pull apart all electrical connections, spray them with contact cleaner, dab on some contact grease and snap everything back together. Go one wire at a time, and don't get frustrated. You do not need to remove the wires from the bike, but it helps to remove the gas tank and side panels. If there is no spark, the contact breaker can be cleaned and adjusted, we'll get to that later, its not tough. -Take the carburetor off, dissassemble it (you will need some small screwdrivers) set the choke plunger aside (it has rubber parts on it) and dip everything else in a 1 gallon can of carb cleaner. This stuff is available at auto parts stores. While you are there, grab a roll of gasket material and an exacto knife, you will need to make a new gasket for the carburetor float bowl. Again this is easy, just place the bowl down on the gasket material and trace the outside of it with the knife. The take the cutout and remove the inside of it leaving a 3/16" (approx) wide rectangular strip. Punch some holes in it at the corners so the screws can pass through and you are done. It can be frustrating but you'll get it. Once all the parts come out of the cleaner, rinse them in water and use compressed air to blow everythin dry, and to clear all the tiny holes in the carb body. Reassemble, turn the air screw in until it bottoms (go easy on it or it will strip) and turn it back out 1-1/2 turns. Reinstall on the engine and connect the fuel line. If you have compression, and you have a spark, and you have a clean carburetor, your bike should start. Give it a good going over based on what I talked about above and get back here for further info. Link to comment Share on other sites More sharing options...
DeadStar Posted June 30, 2009 Author Share Posted June 30, 2009 Thanks for the advice Tylerman. I actually read through all your posts about fixing your rs100 before I joined the forum. Currently I know it needs a battery, because it doesn't have one, but the guy I bought it from said the guy that gave it to him drove it to his house and that was about 6 months ago. Also the kick start has a crack in the connector and needs to be replaced, but I don't think that it would be a big deal for me to use it to try to start the bike. Of course, I was planning on flushing out all the fluids and doing a tune-up before I try to start it. I do know that the gas tank has some slight rust inside and I'm not sure what to use to clean that out. I will be taking some before pictures of the bike soon and put them up. It was funny that the guy who sold it to me told me it was just a 1974 Yamaha 100 and after searching for a while and not finding anything really about it I called Yamaha gave them the vin and found out it was a 76' rs100, which actually made me like it more. It has the original green racing paint and only 4200 miles on it. Link to comment Share on other sites More sharing options...
Tylerman Posted June 30, 2009 Share Posted June 30, 2009 Cool, happy to help. I got some differing opinions on my bike's lineage, I though for the longest time it was a 74, but from what I can determine Yammy didn't start making them until 75. Go figure. Rust in the tank is a no brainer, if you can get it in California try and find a product called evap-o-rust. Take the tank off the bike, screw the gascap on tight, put a piece of fuel line between the crossover nipples, and close the petcock, then fill that tank up with the stuff. Leave it for a day or two, turn it occasionally so the chemicals get sloshed around, your tank should look great afterwards. Link to comment Share on other sites More sharing options...
DeadStar Posted June 30, 2009 Author Share Posted June 30, 2009 Cool, happy to help. I got some differing opinions on my bike's lineage, I though for the longest time it was a 74, but from what I can determine Yammy didn't start making them until 75. Go figure. Rust in the tank is a no brainer, if you can get it in California try and find a product called evap-o-rust. Take the tank off the bike, screw the gascap on tight, put a piece of fuel line between the crossover nipples, and close the petcock, then fill that tank up with the stuff. Leave it for a day or two, turn it occasionally so the chemicals get sloshed around, your tank should look great afterwards. Thanks. I will definitely try that. Link to comment Share on other sites More sharing options...
Tylerman Posted July 1, 2009 Share Posted July 1, 2009 Mine is also the Racing Green color with gold decals. Good luck wth this bike, and definitely post up some pictures. I had mine for years before I finally bothered with it and now I regret that I waited so long. Small bikes are a blast. Except the Buell Blast, ironically, they are dogs. However my Kona Blast mountain bike kicks arse and glows in the dark. Man, I've had too much coffee this morning. Link to comment Share on other sites More sharing options...
JimR Posted July 1, 2009 Share Posted July 1, 2009 Thanks for the advice Tylerman. I actually read through all your posts about fixing your rs100 before I joined the forum. Currently I know it needs a battery, because it doesn't have one, but the guy I bought it from said the guy that gave it to him drove it to his house and that was about 6 months ago. Also the kick start has a crack in the connector and needs to be replaced, but I don't think that it would be a big deal for me to use it to try to start the bike. Of course, I was planning on flushing out all the fluids and doing a tune-up before I try to start it. I do know that the gas tank has some slight rust inside and I'm not sure what to use to clean that out. I will be taking some before pictures of the bike soon and put them up. It was funny that the guy who sold it to me told me it was just a 1974 Yamaha 100 and after searching for a while and not finding anything really about it I called Yamaha gave them the vin and found out it was a 76' rs100, which actually made me like it more. It has the original green racing paint and only 4200 miles on it. Hi Deadstar, should be cool 9 times out of 10 if the bike has not been stored correctly your big headache will be the carb the cylinder/piston can be restored quite easy along with the ignition system ... lets us know who it goes Regards Jim Link to comment Share on other sites More sharing options...
DeadStar Posted July 1, 2009 Author Share Posted July 1, 2009 Here she is as I bought her. I will be starting work on her when I get paid on the 5th and will post progress pictures as well. Link to comment Share on other sites More sharing options...
Tylerman Posted July 2, 2009 Share Posted July 2, 2009 Here she is as I bought her. I will be starting work on her when I get paid on the 5th and will post progress pictures as well. Lucky dog, you have the magneto cover, those things are like hens teeth. I know there's one on eBay right now, but they are generally hard to find. Overall looks really nice, you shouldn't have any problems with it. Certainly in better condition than the one I have. Link to comment Share on other sites More sharing options...
DeadStar Posted July 2, 2009 Author Share Posted July 2, 2009 Lucky dog, you have the magneto cover, those things are like hens teeth. I know there's one on eBay right now, but they are generally hard to find. Overall looks really nice, you shouldn't have any problems with it. Certainly in better condition than the one I have. Ok this is a stupid question. What's the magneto cover? Link to comment Share on other sites More sharing options...
Tylerman Posted July 3, 2009 Share Posted July 3, 2009 Ok this is a stupid question. What's the magneto cover? The cover over the magneto on the left side of the engine. It has "Yamaha" embossed in it. Mine does not have it. Most that I have seen do not have it. I realize that in order to get to the points it must be removed, but I don't know why it would end up missing and so hard to find in so many cases. Anyway, count yourself lucky. Link to comment Share on other sites More sharing options...
DeadStar Posted July 3, 2009 Author Share Posted July 3, 2009 The cover over the magneto on the left side of the engine. It has "Yamaha" embossed in it. Mine does not have it. Most that I have seen do not have it. I realize that in order to get to the points it must be removed, but I don't know why it would end up missing and so hard to find in so many cases. Anyway, count yourself lucky. That is kinda weird. I don't see how someone could really lose that part. Link to comment Share on other sites More sharing options...
JimR Posted July 4, 2009 Share Posted July 4, 2009 The cover over the magneto on the left side of the engine. It has "Yamaha" embossed in it. Mine does not have it. Most that I have seen do not have it. I realize that in order to get to the points it must be removed, but I don't know why it would end up missing and so hard to find in so many cases. Anyway, count yourself lucky. Hi, it was only a sticker when the weather got underneath it it tended to loose adhesion to the case .. some of this would be cured if the selling dealer pulled the cellophane from the sticker but earlier bikes the logo was embossed into the cover ! Regards Jim Link to comment Share on other sites More sharing options...
DeadStar Posted July 4, 2009 Author Share Posted July 4, 2009 Hi, it was only a sticker when the weather got underneath it it tended to loose adhesion to the case .. some of this would be cured if the selling dealer pulled the cellophane from the sticker but earlier bikes the logo was embossed into the cover ! Regards Jim So, I did get lucky. Sweet. Link to comment Share on other sites More sharing options...
JimR Posted July 4, 2009 Share Posted July 4, 2009 So, I did get lucky. Sweet. Hi Deadstar I guess so ! Regards Jim Link to comment Share on other sites More sharing options...
Tylerman Posted July 6, 2009 Share Posted July 6, 2009 A decal? Not on mine, it is a rounded aluminum cover with three screw holes in it, it attaches to the left engine/sprocket cover. And if I am not mistaken Dead you have the same thing. Either way, yes count yourself lucky to have it. Link to comment Share on other sites More sharing options...
JimR Posted July 7, 2009 Share Posted July 7, 2009 A decal? Not on mine, it is a rounded aluminum cover with three screw holes in it, it attaches to the left engine/sprocket cover. And if I am not mistaken Dead you have the same thing. Either way, yes count yourself lucky to have it. Hi Tylerman by 1976 in the UK we had a decal (bar some old stock kicking around) but of course this may be different for different parts of the world .. and as you say if you have it flaunt it !!! Regards Jim Link to comment Share on other sites More sharing options...
Joshua2 Posted July 9, 2009 Share Posted July 9, 2009 Put a small amount of fresh neat petrol, just a spoon full, direct into the plug hole. Use a new spark plug, they are cheap and with the ignition on crank it over. If it runs for a few seconds then dies its probably a fuel supply fault that you have got. e.g. carb, bad petrol etc. Hope that helps, J Link to comment Share on other sites More sharing options...
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