Rebuilt and working out some bugs

Discussion in 'Tech Area' started by Tripod, May 4, 2018.

  1. Tripod

    Tripod Member

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    I just finished assembling my z50 k1 today. The motor is unknown if it ran prior to coming into my possession. After gathering all the necessary pieces and putting the bike together, it wont start.

    The points are gapped at .016. The plug is gapped at .027. I dont know if they coil is good or not. I pulled the plug to see if there is spark, but didnt see any. Im not sure if I have sanded off enough paint around the key switch. When I put the switch in the second on position, I dont get any lights even though the battery is new. Valves were set at .002 and .003ex. Carb cleaned and rebuilt. Fuel is entering the bowl. I pulled the plug out after a bunch of kicks and it wasnt wet or smelly.

    I did a compression test and it was at 85psi. Pretty sickly.

    Should I bother going over basic things or should I go right in to a head rebuild?
     
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  3. racerx

    racerx Administrator
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    I doubt that it's going to fire, with 85psi...that's pathetic.

    Regardless, without spark, it wouldn't matter if it had 185psi. An engine needs: air, fuel, compression and spark...at a minimum. Without any one of those, it's a paperweight. For now, try running a jumper lead from the stator (primary) ignition coil to the HT (secondary) ignition coil; that bypasses the wire harness entirely. If you get spark, then you know where to look...keyswitch & harness. If there's still no spark, time to check the points, condenser & both coils. The coils can be checked using an ohmmeter. Checking a condenser is a trial & error process; you replace the points & condenser as an assembly (normal practice, cheap too) an see what happens...that's where I'd start, based on the info you provided. Regardless of what you end up discovering & correcting, by the time this is ready to ride, starting by getting the ignition working now makes a lot of sense. With a properly working ignition, further diagnoses are a lot easier.
     
  4. hrc200x

    hrc200x Active Member

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    For the compression issue, if your lucky the rings might just be lightly stuck to the piston or the cylinder dry from sitting. When you get spark you could try roll starting the bike in 3rd gear, that seems to get things turning over faster than a kick start and maybe it will fire. If you put a little bit of oil in the cylinder and do a compression check and it bumps the reading up that means its in the rings, if no change its probably valve related. Think the secondary coil also needs a good ground to the frame.
     
  5. cjpayne

    cjpayne Well-Known Member

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    Did you have it at WOT when you did the compression test?
     
  6. Tripod

    Tripod Member

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    Yes, it was at WOT. I'll try the oil tomorrow and see.

    I ran a jumper from the black sheathed wire out of the harness directly to the coil. No spark. Guess I know where to start tomorrow.

    Check grounds on coil to frame.
    Check points, condenser. Check for excess solder and or grounding.
    Check points gap.

    Anything else?
     
  7. hrc200x

    hrc200x Active Member

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    Are the points new or used? If used did you file them before gapping? If not try that first.
     
  8. Tripod

    Tripod Member

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    Ignition all the way to the spark plug is new except for the coil and coil cap.
     
  9. kirrbby

    kirrbby Well-Known Member

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    Be sure the points wire is in the right spot on the points...right at the end of the screw under the nut and washer I think.

    On the Z50's it's easy to just unplug the ignition switch from the wire harness, and the bike should spark, and run. That would eliminate the possibility of a bad switch.
    Trim ¼" off of the spark plug wire..?
    Try a new plug.
    Check for continuity between the coil body and the engine case.

    Sanding around the ignition switch should not prevent it from sparking, if anything it would not allow the switch to kill the engine...and maybe affect lighting.
     
  10. kirrbby

    kirrbby Well-Known Member

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    No bare wires or solder touching the metal body of the condenser, or anywhere on the stator plate etc.
     
  11. kirrbby

    kirrbby Well-Known Member

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    You could show us a pic of the stator plate if you get back in there.
     
  12. cjpayne

    cjpayne Well-Known Member

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    The engine to frame contacts need to be clean too or the engine wont ground to the frame.
     
  13. Tripod

    Tripod Member

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    Readjusted points and tried a different plug. Still nothing. Heres a pic of the stator.
     

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  14. OLD CT

    OLD CT Well-Known Member

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    Looks like the yellow wire is touching the condenser or you overheated it with too much solder. Less is is more with the solder.
     
  15. kirrbby

    kirrbby Well-Known Member

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    Ya it looks like that yellow wire end may be touching the condenser. Also, the points wire end, may be touching the blackish spring on the points.
     
  16. allenp42

    allenp42 Active Member

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    Take a look at the arrow I added to your pick. If this is remnants of insulation - no problem. If this is part of a tab or wire, I would check to make sure it's not touching the side of the condenser, because it will prevent you from ever getting a spark. (i.e.: grounds out the condenser/points/coil)
     

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  17. Tripod

    Tripod Member

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    It runs!

    The jumper wire to the coil is the way to go to cut through all the BS.
    I moved the area in yellow to green. It looked as if it were rubbing on the flywheel. I could see a light scrape.
    I moved the areas in pink. I bent them so they climb up and then bend to connect to the lightning coils.
    The wire in red was the big problem. It wasnt soldered on well. It came with over an inch of exposed wire. Instead to shortening it, I wrapped the excess around the condenser tabs. Then soldered. I guess I didnt do a good enough job. I hate soldering.

    I also checked the wiring and key switch. I could still get spark without the jumper wire.
    I put oil down in the cylinder and did a compression test. It is at 120psi.

    Next problem. When I switch over on the key switch to II, I dont get any lights, headlight or taillight.
     

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  18. racerx

    racerx Administrator
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    Sounds like you've got some detective work ahead, with the keyswitch & wire harness. That said, I concur with OLD CT & kirrbby, condensers don't like soldering heat and "less really is more". Use the least amount of solder applied in the shortest duration possible, to prevent heat damage. As long as your ignition works, I'd leave the condenser as-is...if it's fixed, don't broke it.;)
     
  19. Tripod

    Tripod Member

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    I have voltage at the tail light, rectifier, and the front stop switch functions.
    No voltage at the headlight when off.
    Tail light doesnt function on I or II.
    The wiring harness is brand new, and so is the key switch. I swapped out the key switch with an old one with same results.
     
  20. racerx

    racerx Administrator
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    Sounds like more than one issue.

    HL power is AC...fed directly from the yellow stator lead and only whilst the engine is running. Easy way to test the electrical system, unplug the harness from the stator, then feed 6vDC to both the yellow & white leads of the wire harness. That'll give you power across both the charging & HL circuits, without running the engine.

    If you're getting 6vDC at the tail light, but it doesn't illuminate...including brake light function, then I'd be looking for a bad ground, most likely at the TL body, though it could be at the keyswitch, or a combo of both.
     
  21. Tripod

    Tripod Member

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    Tail light will illuminate. Both brake switches are working. I forgot to tighten the mounts for the light. I left them loose in order for the bracket to mount up to the fender. Then forgot all about it in the excitement of being able to hang parts.

    I disconnected the harness out of the stator With 6v DC being jumpered into the pin for the yellow wire out of the stator, still no headlight. Im getting 6 volts at the wire on the harness going into the headlight bucket.

    I bought a china headlamp instead of spending the extra cash on a stanley, probably wont do that again.

    I have the grey red wire going into the brown wire for the high low. The white wire on the high low is going to the white wire on the headlight. The blue wire from the high low goes to ths blue wire on the headlight. The blue high beam indicator wire goes into the y connector on the headlight.

    The headlamp came with a male bullet connector for the ground on the headlamp. There also was a male bullet connector on the green yellow wire on the high beam indicator. Do these two get connected?

    With the 6V DC jumper, i was able to get the lamp to light up with the brown wire plugged into the harness, white to headlight, and the green headlight wire jumpered to a ground on the cylinder head.
     

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