jordanscycles Posted July 20, 2009 Share Posted July 20, 2009 So i picked up this bike yesterday from a guy that had it under a bike cover in his back yard for an unspecified amount of time. He said he could never get it to run for more than 10 minutes. I went through and oiled the slides, cleared the main jets even though they didn't really need it and put a few drops of wd-40 on the needle valves. The floats looked good but I did not check the level. So basically this bike will run on the first of the two choke settings, which is half choke. I was able to ride it like that last night and it ran ok. It sputtered and back fired when you let the throttle off, just as it does when its idling without load. But when I gave it gas it quickly picked back up. But I've never really rebuilt carbuerators, so I was wondering where to start with it. I heard of boiling them in lemon juice among other acidic liquids. Also when I opened the carbs up I noticed that there were the main jets that looked normal, but I couldn't see the idle jets, and there was like a screw that sealed them off it looked like, which I find crazy weird. And one other thing, the brass pieces the main jets screw into were loose and out of place. So I pushed them both back down, one of them clicked into place. Any tips would be appriciated. Link to comment Share on other sites More sharing options...
jordanscycles Posted July 20, 2009 Author Share Posted July 20, 2009 im going to get new stock jets. Link to comment Share on other sites More sharing options...
Moderator drewpy Posted July 20, 2009 Moderator Share Posted July 20, 2009 need to strip the carb down (separatly) and if you can, use an ultrasonic bath. don't use lemon juice as it will blacken the alloy and left long enough, will corrode it. you can clean the outside by using baking soda blaster check settings against spec. i'd use 26mm for float height the mains screw into the emulsion tube which when unscrewed( and the diaphram removed) will fall out. there is a location tab to stop them turnig when the main jet is tightened. use a carb cleaner and compressed air to clean drewps Link to comment Share on other sites More sharing options...
duaneage Posted July 20, 2009 Share Posted July 20, 2009 Beautiful bike, even the gauges look new. I would replace the intake boots between the head and carb, especially if they are cracked. 32 dollars on ebay. Check the petcock, the o ring inside mine was crudded shut so I replaced it with a new o ring from a plumbing supply store. It should flow on PRI without the engine running, and on RES or ON with vacuum applied to the hose behind it. Poor fuel delivery can also be caused by a clogged screen in the tank, ask me how I know. If you decide to run a filter, get a small lawnmower filter, not a large one since it will vapor lock. Remove it once the tank is clean. Link to comment Share on other sites More sharing options...
jordanscycles Posted July 21, 2009 Author Share Posted July 21, 2009 Well I tore them apart yesterday and began cleaning everything with a toothbrush and some WD-40. I went to the local Yamaha shop and got brand new jets, about 3$ a piece. The inside of the carbs were pristine I must say, but someone put in bondo or something over the main air mixture screw hole inside the right side carb. So I scraped that off not even starting to wonder why they'd do that, put the jets in, new plugs, new fuel line, checked the petcock (worked perfectly). I assembled them slowly, taking my time to do it right. After all that, I turned the bike on pushed that beautiful button and it fired right up (after letting it be on prime till full then switching to on). I rode it around the neighborhood several times. The transmission is tight and feels very good. But yeah I picked this thing up for 450$ on craigslist from some guy that wouldn't spend any money or take the time to get it going. It really does look amazing, opening the seat and all the wires and the frame paint looks great. I cleaned it today and applied and reapplied aluminum polish (mothers) and it's going to need a few more buffings from that but I am very happy with this bike. I am 16 years old and this will be my first bike. My dad bought one of these brand new in 1980 and rode it for a few years till he got in an accident on it and sold it. By the way, we ordered the throttlebody off ebay and the card board is just precautionary because we are selling the house, it doesn't leak.. Link to comment Share on other sites More sharing options...
Moderator drewpy Posted July 21, 2009 Moderator Share Posted July 21, 2009 glad to hear you got it sorted pretty easily, well done! Link to comment Share on other sites More sharing options...
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