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Need help

Discussion in 'The Garage' started by khizer, Oct 8, 2019.

  1. khizer

    khizer XS400 Member

    hey everyone, this is khizer. I am from Dallas, TX and I bought a 1978 XS400 2E. I don't have any keys for it and I am trying to get this thing at least started so that I could have a hope that it will run one day. A little background about me, I am 20 years old and have little knowledge about engines and running of a vehicle (also my parents are against me for buying this vehicle). I bought this bike for 920$ and my ultimate goal is to restore it or give it a modern look / cafe racer. I need your help in starting this motorcycle. Anything that will help me please please post/reply to this thread and I really appreciate your help.
    If you'd like you could also email me at zaynshariff99@gmail.com if you want.
    Thank you
     

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  2. BBS360

    BBS360 XS400 Guru Top Contributor

    Get the manual from here:
    http://www.xs400.com/threads/re-run-free-full-yamaha-service-manual.14495/#post-151524

    Does it kick over?
    You'll probably need to clean the carbs a few times. Lots of forum threads covering that.
    Make sure the battery is good or get a new one.
    You'll want to make sure all the wiring is connected where the missing headlight goes. You won't need the headlight to initially get the bike running but you'll need one eventually.
    eBay will be a good source for parts
     
  3. XSLeo

    XSLeo XS400 Junkie

    Once you get a good battery installed, look inside the headlight bucket. You will find the wires that come down from the key switch. Three wires. Red Brown and another. often blue. The red and brown are the ones you want. Unplug the switch wires from the harness. Build a jumper wire that you can plug in to the red and brown wires. This bypasses the switch.
    Better use two wires and most and toggle switch for testing. That way you can easily turn the power off and on.
    Now with power on. In neutral, Clutch pulled in, see what happens when you push the start button. It may or may not crank. If not turn the engine stop switch to run, try again.
    If it turns over. Pull a plug. Plug back in plug wire. Hold plug on side of engine. Turn engine over while watching plug. Does plug spark.
    Then you have got a good possibility of getting it to run.
    You can try starting it but I an most others would recommend pulling the carb, tearing them down and cleaning them first.
    Many good posts on carb cleaning.
    Might want to clean the tank too.
    With a clean fuel system then try starting.
    I would also recommend starting at one end of the bike and pulling apart every electrical connector and cleaning them. Work you way to the back of the bike. This can often fix a lot of electrical issues before they become issues.
    There may be a number stamped into the switch. Or maybe the seat lock. possibly the fuel cap. There are places on the net that have keys if you have the number.
    Leo
     
  4. XSLeo

    XSLeo XS400 Junkie

    DON'T try jumping it from a running car battery. The sudden surge of power from the cars alternator can damage your electrical system.
    Get a good bike battery.
    Leo
     
  5. khizer

    khizer XS400 Member

    hey Leo, I have a battery jumper pack do you think that would work it? also any idea that if the bike was a good deal or not for 920$?
    Thanks
     
  6. khizer

    khizer XS400 Member

    thanks for all the steps. I cannot thank you enough, also the bike doesn't have a self starter its a kickback. So I should probably follow the same steps right? and do you know what signs I should look out for if I want to know whether the engine is seized or the headgasket is blown out or whether the engine need the rings to be replaced (god forbid).
    Again thanks for the help.
    -khizer
     
  7. NewHavenMike

    NewHavenMike 1976 XS360C Top Contributor

    It would be a shame to ruin that original gas tank. If you plan to cafe the bike or cut it up, the bike will be worth much less.

    Where I live, I think you paid way too much. For that reason, Id restore it to original condition and keep the value much higher up. Start with a different bike. Theres not a lot of aftermarket support for the XS bikes. A lot of us depend on finding used parts on EBay and buying whatever you can find when it pops up. As long as you dont open into the engine, you should be alright. Honda ownership is not so much like this... Having said that, Yamahas are the best lol

    Take the sparkplugs out and squirt some oil in there before you jam the kicker a 1000 times. Keep the run switch turned off until you are ready to start it. Pour some gas in the spark plug holes and see if it will kick over. The bike needs a good battery to start and idle.
     
  8. XSLeo

    XSLeo XS400 Junkie

    With just a kick start, no e-start it may be ok for some testing.
    It may not work so well if it runs. Holding the jumper pac while the engine running and looking things over might be a bit of a trick.
    As far as value, you thought it was worth it, so it must have been.
    Was it too much for me to pay? I might if it was a known runner and in immaculate condition, or very nearly so.
    If the cylinders are clean looking then there is a good chance the head gasket is ok. Often a blown head gasket leaks oil to the outside.
    One way to check that is with a compression tester. Some auto parts stores loan out tools. Perhaps one near your has a compression tester to borrow.
    When doing the compression check the actual numbers are not as important as how close to the same they are. Within 10% is allowable.
    As a bike sets the cylinder walls and rings get a bit rusty. This can let the compression read a bit low. If your book says the compression should be 165 for a reading and you get 125, That's ok for now. Once you get the bike running the rust wears away quickly allowing the compression to come up. I wouldn't worry to much till I've run it a few hundred miles. Then if it hasn't come up I would look more into it.
    Doing the carb and tank cleaning is something I would do before going much farther.
    I'm a member over on our sister site, XS650.com. The 80 up XS650 used BS34 carbs that is very similar to the XS400 carbs.
    One of the main differences is the Throttle cable and idle speed adjuster are on the left side of the carb set instead of between the carbs.
    The Carb Guru's Over there wrote a very good guide for the carbs. It covers the 70-79 BS38 carbs as used on the XS650 as well as the BS34's.
    www.amckayltd.com/carbguide.pdf
    It describes step by step procedures to tear down, clean, inspect your carbs. Once you do the inspection you can then determine what needs fixing. What parts you may need.
    Then it explains how to make adjustments as you go when you assemble the carbs.
    The XS400 has different jetting and other specs but the folks on here can help with those.
    Once you have them clean, on the bike and the bike running it has a tuning section. It gives you a test then by the results of the test it gives you info on what to adjust.
    As you tune the carbs it's best to make One change, test, one change, test. If you do two or more things you can't tell which change made it better or worse.
    Leo
     
  9. khizer

    khizer XS400 Member

    thanks for the reply. I was thinking to paint the gas tank and the rear plastic hump thingy as it has some discoloring, change the handlebar to clip ons, and maybe spray paint the chrome on the tires black.Also someone messed up the seat lock and the seat doesn't sit in properly not to mention there's rust on the bottom of the seat so I am thinking to restore it or get a new seat those are the only mods that I am thinking to do on it, do you think that's reasonable or should I keep the bike as it as.
    I am regretting that I paid that much amount of money since I brought it home, my parents don't even know it since I am fixing it in a van. Although I have used my own money to buy the bike my parents are against it as they obviously think that its a waste of time fixing it.
    I really hope that the bike starts up with all the steps mentioned, also do you think I could start the bike using a car battery jumper?
    Two last questions for you/someone reading this:
    On the exhaust valve there's a rubber screw instead of a valve screw is that ok?./ normal
    last question by the throttle, there's a switch that says engine STOP, the switch spins freely but will that effect when I'll try to start the bike.

    Thanks for your time, helping me out. I am sorry if I am being too curious its because I am a amateur person in bikes and you guys are my last hope helping me out.

    I have attached pictures below of my bike for better understanding
     

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  10. khizer

    khizer XS400 Member

    thanks for your reply man. I am gonna start working on my bike by next week hopefully and gather all the information needed to get started meanwhile.
    Again, I greatly appreciate all your help. Hope you guys could help in future if I have any questions.
    Thanks
     
  11. khizer

    khizer XS400 Member

    hey y'all, just wanted to thank you guys and give quick update. The bike runs, I was able to check compression, changed the plugs & oil, cleaned the carbs hooked a battery jumper. Boom! the bike started. The only thing is that after the bike started running, gas started pouring out of the right air filter and there was chirping sound from the right side of the engine. I think this might have happened because of the intake rubber boot was missing a HEX bolt and the gasket is messed up but I am not 100% sure on this since I am not a pro.
    So, if any one could give me advice on how I could fix this I would eminently appreciate them. Regardless, I both a pair of intake gaskets and I am trying to buy the HEX bolts but they are really expensive (2 for $7.69 on ebay).
    I also wanted to request for suggestions for pod air filters and when should I know to change the clutch plates or care about the transmission going bad/symptoms?
    Again thanks for helping me out.
    -Khizer
     
  12. xschris

    xschris a lifestyle not a trend Top Contributor

    Keep the stock air intake setup. Pods are a waste of time and money if you still have your stock setup. Make sure your floats are set to the correct height (26mm) on the carbs. You may need new float valves if they still leak. Go to a local hardware store to get them bolts. It will save you a few dollars.
     
    khizer and buztabuzt like this.
  13. NewHavenMike

    NewHavenMike 1976 XS360C Top Contributor

    The clutch discs have a thickness tolerance that you can check if you really want to pull all of that apart for no reason.. Different engine oils will have some influence on clutch/transmission operation and smoothness. Its all about what your bike likes though, you will have to experiment with that.

    If the clutch doesnt slip, its good. Sometimes, the clutch might slip a bit at high rpms when the engine isnt fully warmed up. You shouldnt be heavy on throttle anyways when the bike is still warming up so this is easily avoided if you care for your machine.
     
    khizer likes this.
  14. khizer

    khizer XS400 Member

    Thanks for the replies @xschris and @NewHavenMike.
    Does anyone know why the motorcycle was making the chriping sound.
    Is it because of the air leak? (there was gas coming out of the right air box when the bike was running)
    The floats were in quite good condition when i cleaned them carbs, @xschris should I replace them if at all the gas leak was because of the floats.
    @xschris I wanted to replace the stock air box as the plastic on of the air box was broken/cracked and the screw won't fit in properly (please see the picture).
    Hope y'all could help me out
    thanks
     
  15. xschris

    xschris a lifestyle not a trend Top Contributor

    I would check your float height. It should be 26mm. I have good stock air box parts if you need something.
    DSC03752.JPG DSC03751.JPG DSC03753.JPG
     

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