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pamco failure?

Discussion in 'The Garage' started by cosworth, Mar 3, 2019.

  1. cosworth

    cosworth XS400 Enthusiast

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    I was riding home from a quite chilly but sunny rip through town. Sitting at a light, turning left. Coast was clear, gave it some gas and clutch and it bogged. Exhaust went a kinda bassy tone and I figured some junk had clogged a jet or a coil failed. Nursed it home on one cylinder and I found the left exhaust stone cold. It wasn't firing I assumed (correctly).

    Pulled the plug and turned it over, grounded to the head. No spark on the left. Swapped caps. Not the resistor cap. Swapped plug. Not the plug. Tank off. Checked Pamco to coil wiring. Fully intact. Pulled the coil. 4 and 9 on the multimeter. Coil fine. Checked for current at the Pamco. Both sides are getting battery voltage.

    I emailed @pamcopete to see if he had a test procedure for the actual unit. Anyone had this happen?
     
  2. NewHavenMike

    NewHavenMike 1976 XS360C Top Contributor

    When my Pamco failed, both sides burned out because the voltage regulator failed. Evidence of failure was apparent on the Pamco. One of the resistors on each pickup boards was burned and discolored. I have pics in a thread I created.
     
  3. cosworth

    cosworth XS400 Enthusiast

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    Luckily no cold solder or burnout marks on the pamco. It's one degree above freezing outside today. And in the garage. I'll see if the condenser connector wires have power since I power the orange wires on the pamco from that connector. Once it warms up outside. lol.
     
  4. cosworth

    cosworth XS400 Enthusiast

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    Well, bike has zero spark now. Solid 12v at the connectors.

    Checked continuity powered off. Seems one of the main transistors on the Pamco has failed.

    I think I’ll put the points back in.
     
  5. xschris

    xschris a lifestyle not a trend Top Contributor

    That's one thing about points, they will never fail. Just wear out.
     
  6. NewHavenMike

    NewHavenMike 1976 XS360C Top Contributor

    Are you using the original mechanical regulator?
     
  7. cosworth

    cosworth XS400 Enthusiast

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    Indeed. I use the stock advancer.
     
  8. NewHavenMike

    NewHavenMike 1976 XS360C Top Contributor

    Theres a good chance that the voltage regulator is no good. Mine failed within a couple of rides after I stored my bike for winter. So you have the Pamco without the E-advance? Thats an old one. I recently bought one that was never installed.
     
  9. cosworth

    cosworth XS400 Enthusiast

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    My voltage regulator is just fine. It’s not the OEM Yamaha one. Very upgraded from the mechanical idiocy they had.
     
  10. cosworth

    cosworth XS400 Enthusiast

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    Put the points back on. Fired right up. My pamco is a door stop now.
     
  11. xschris

    xschris a lifestyle not a trend Top Contributor

    These seem to do this a lot. The xs650 guys love these but it looks like the xs400 ones don't hold up well. These also use two triggers instead of just one.
     
  12. cosworth

    cosworth XS400 Enthusiast

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    I feel pretty lucky it half failed and got me home at least. Then fully gave up the ghost in the garage.
     
  13. BBS360

    BBS360 XS400 Guru Top Contributor

    I'd be interested in having a look at it if you don't plan to repair it.
    Might have components that would work.
     
  14. NewHavenMike

    NewHavenMike 1976 XS360C Top Contributor

    Id be willing to bet that I have the last new Pamco!


    I picked it up a couple months ago. I also still have the other E advance set that broke. Im not sure what Im going to do with this new one. I was going to install it but decided not to.

    There has to be a reliable electronic system that can be retrofitted. I was looking at units for Honda twins trying for some sort of hybrid.
     
  15. cosworth

    cosworth XS400 Enthusiast

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    I’ve contemplated grafting the system off the other 400 wiring harnesses/bikes/motors I have.
     
  16. BBS360

    BBS360 XS400 Guru Top Contributor

    What do you mean? Has he stopped manufacturing?
     
  17. NewHavenMike

    NewHavenMike 1976 XS360C Top Contributor

    I have no official knowledge about Pamco Pete, I dont mean to misinform. I was basically ignored when I contacted about sending my unit back for a repair. It was within the 1 year warranty and hoped for a full replacement. I waited for a response and tried some more only to get nothing. By then, the 1 year had passed and I had already switched back to points and I just ate the loss of it.
     
  18. cosworth

    cosworth XS400 Enthusiast

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    Broke out the multimeter again today. The g4bc30u rectifier failed. I might replace them both with a high quality - high temp version.
     
  19. BBS360

    BBS360 XS400 Guru Top Contributor

    That's the IGBT that fires the coils. Pete's e-advance version for 80-82 models used an aluminum case to better dissipate heat from them.

    I have a bag of some IGBTs with a higher current capacity. Some of the other specs differ slightly.
    Welcome to them if you're going to try a repair.
    Will check the specs when I get home.
     
    cosworth likes this.
  20. BBS360

    BBS360 XS400 Guru Top Contributor

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