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Could my coil be bad

Discussion in 'The Garage' started by Focal, May 28, 2011.

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  1. Focal

    Focal XS650 Enthusiast

    I bought my 81 xs 650 about ten years ago. Drove it for a couple of years and it started missing real bad. At the time i was twenty and all i really cared about was drinking. I drove it to my uncles and it acted up again, and i said i had it with this junk, I told him to trash it. Like i said i didn't care about much. Well about eight years later i seen my uncle again and he said you know i still have that bike of yours its in my shed. So i drove to his house and got it back. Now i am trying to get it to run again. I didn't know much about engines when i bought the bike but now i am ase certified and been a mechanic for about five years. I've been reading all the posts and this site has been such great help (except for the thread about using integra piston rings, don't do it) and i am thankful. So first thing i did was change the oil, new plugs, and a new battery. I put gas in it and it just pours out of the carbs. I then took apart the carbs cleaned and blew air through. I kick it over and it will not start. I put the choke on and on the second kick it starts for all of two seconds. This bike is paying me back for leaving it to rot away, lol. So i do a compression check 100 psi on the left 70 on the right, yuck. leak down checked it and air comes through the pcv system, rings are bad. so i read about the integra rings and i order them. They are ok except for the oil expansion rings, my advice get the right stuff. Honned the cyclinders put the rings on (replaced the cam chain guide while i was in it) long story short compression now at 120 on both sides...yippppeee. Go to kick it over and same result start for all of two seconds. So redid my carbs. Then i put what i call a fire wire on it (wire in line of spark plug wires with a light that lets you know if the coil sparks) Coil sparks then goes out. Now on to my question. Reading a post from inxs, i ohmed from spark plug cap to spark plug cap and measured a out of range in a 200k setting. Is it safe to say my coil is bad? Any recommendations?
     
  2. Classic

    Classic rackin' up the miles

    Plug wires and boots go bad, too. Have you returned your carbs to factory settings and synced them?

    Check your carb maniolds for cracks.
     
  3. What is wrong with the integra piston rings in an XS650 engine?


    Lawrence
     
  4. Skip

    Skip XS 650 Screwturner

    Focal
    Welcome to the club!
    When checking the secondary windings on your coil,I suggest you take off the resistor spark plug caps to get a true coil reading,if they are on there you have to allow 10k to your readinds(5k per cap).
    I like taking them off and then checking each cap.I had a cap go bad last summer and it had almost 10k resistance.The bike would flatten right out like it was starving for gas,but was actually just running on 1 cylinder.
     
  5. Focal

    Focal XS650 Enthusiast

    i synced my carbs to the best i could, without it running i can't tell if they are spot on though. No cracks in the holder that i can see. I took my coil off yesterday and i took the spark plug caps off and ohmend the secondary again, same thing resistance over 200k (thats the highest setting i put my meter on). I then was convinced it was the coil. I took my flat screwdriver and chiseled the casing off the coil removed the spark plug wires and then ohmed straight off the coil secondary itself and still no reading (above 200k). Of course now i will have to get a new coil regardless, but according to what i read here, it checked bad. Oh.. with the integra rings, the oil expansion ring would not seat properlly into the piston, other then that it would have worked, or at least i then would have attempted it.
     
  6. gggGary

    gggGary Fiddle Futzer extraordinaire

    We will soon know if it was the coil but uh don't hold your breath. I mean I hope that's it but..... An 81 with the TCI has a few safety interlocks and the the usual 30 year old wiring connections.. Go through the whole ignition troubleshooting guide in the manual.
    Post your location maybe a near by owner can help by swapping in known good parts if it gets to that.
     
  7. Focal

    Focal XS650 Enthusiast

    well i got my coil from mikes xs and new wires and plug caps put it on now it runs longer ( im up to about 7 seconds) but still dies. I don't know alot about carbs, but im starting to think that fuel is the problem. I was wondering is there a way to check if i am getting fuel without spraying fuel into the carbs? i ask because its hard to kick it over and then spray without it stopping. I only get life out of it when the choke is all on, does this indicate anything? I adjusted the air fuel screw in the carbs three revolutions out (360* equals 1 turn right?). when i first started it i got about 4 seconds runinng out of it. the second i backed off the throttle screw all the way and it ran the seven seconds. this bike has 13k miles on it, it can't be something to messed up. i feel like this is what happens. it sits and fills the bowl up with gas, i start it and it runs for 7 seconds, draing the bowls empty then dies. i kick it over right away after it dies - no start no trying to start- wait about 10 seconds kick it over and it runs for the short time. HELP:banghead:
     
  8. Classic

    Classic rackin' up the miles

    Give those carbs a thorough cleaning through all of the passages. Everything you could want to know about xs carbs is in the carb guide within XS650 tech in the top bar. Sounds like you need to set your float height... it should be 22mm from the gasket surface without the gasket to the bottom of the float when the carb is sitting on it's top.
     
  9. gggGary

    gggGary Fiddle Futzer extraordinaire

    Full stem to stern fuel system R&R the one thing you don't PROVE to work will be the problem area. I like to use a plastic lawn mower gas tank for testing and "back to life" tune up work.
     
  10. Focal

    Focal XS650 Enthusiast

    cleaned the carbs again, the rubber caps in the carb were not doing their job (whatever that may be). I put a small bead of silicone around them and put them in. I also cleaned the ports in the side of the bowl. I don't know what part did it but the bike now runs, only with the choke on though. I took it for a 5 mile ride and when i got back oil was everywhere. i did some research and the dipstick i have must be broke and i filled it up to where i seen the oil just touch it and i ended up putting 5 quarts in. I hope that was the problem because i read that this bike only takes 2 quarts. Could anyone clear that up?
     
  11. xjwmx

    xjwmx XS650 Guru

    ^It takes two quarts and a couple of shot glasses.

    Gas dissolves silicone sealer pretty quickly.

    Did you say it runs longer if the choke's on? If so, that's a clue.

    I'm petitioning to have your ase cert. revoked, btw :)
     
  12. XSLeo

    XSLeo XS650 Guru

    It sounds like the ldle circuits in the carb need cleaning. Read this.
    Leo
     
  13. Focal

    Focal XS650 Enthusiast

    i keep reading that carb guide and some of it just doesn't click for me. I was going to take the bike on a longer ride, but then it started wanting to die when i gave it more than 25% throttle. I think those rubber plungers are behind this. I am going to order new ones and also a set of carb holders, i will see if this makes a diffrence. Also when i was checking the turn signals, they did not work. I took the switch on the handle bars apart and it had two broken soders on the switch. Got that fixed at least.
     
  14. xjwmx

    xjwmx XS650 Guru

    You're talking about the three wires that solder into the three little cups. It seems like they are almost always bad and that signals never work right all the time until they get resoldered. They can look fine but just pull right out with your fingers.
     
  15. XSLeo

    XSLeo XS650 Guru

    Rubber plungers?
    Leo
     
  16. azman857

    azman857 XS650 Guru

    BS34s have a rubber cap over(under?) the pilot jet in the float bowl. Its held in place by the float bowl.
     
  17. Focal

    Focal XS650 Enthusiast

    i guess instead of plungers i should say rubber caps. they are next to the main jet, and underneath them are the pilot jets (i think). i belive the purpose of having them is to keep fuel from the bowl mixing in and making the air/fuel mixture to rich. I hope the ones i ordered from mikes will take care of this running issue. And if only shipping took a couple of days would be nice, it usually takes a week to get here to indiana.
     
  18. Focal

    Focal XS650 Enthusiast

    and as far as the oil leak, when i put the piston rings in, i was trying to decide how far to put the camshaft bearings in, well i didn't have them in far enough. The cover that has the camshaft seal was not even touching the block. So i took a axle socket big enough to push the race of the bearing, and knocked the bearings in a little more and then i was able to get the cover to seal. no leaks yet
     
  19. XSLeo

    XSLeo XS650 Guru

    On your cam bearings they should be pushed as far onto the cam as they will go. Then as you set the cam on the head, center the bearings on thier seats. The bearings will over hang on the inside of the seats. This is the way it should be. This centers the cam sprocket straight above the crank sprocket.
    On an engine thats asssembled, you can loosen the head bolts up, then use a socket that matches the bearing inner race to drive from one side till the bearings start to move on the other. This gets the bearings all the way on the cam. Now move the socket to the other side and drive the bearings back till they are centered on the seats.
    I use the depth gauge part of my dial caliper. Measure from the outside of the head where the housings bolt on to the bearing races, same amount on both sides.
    Leo
     
  20. Tomterrific

    Tomterrific XS650 Junkie

    Spray some carb cleaner on the idle jet and poke through once with a thin wire. I know, the books say not to do this, you're just making sure the idle jet isn't plugged because that may very well be your problem (or one of your problems :^)
     

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