Bummer, I hate troubleshooting a new build.

Discussion in 'General Questions' started by Skyliner70cc, Jun 24, 2012.

  1. Skyliner70cc

    Skyliner70cc Active Member

    PK 80
    Aftermarket high compresison head (MM 1st generation style)
    Jaguar CDI
    Dax aftermrket RT carb
    Jaguar CDI
    Tuned Pipe
    Mild porting
    Centrifugal Clutch
    Shift Bike Parts shift kit with lower gearing (small drive sproket, larger freewheel sprocket and mega gear )

    After farting around on this build for about 3 months, I finally finished it up today. I turned fuel on and coasted down my driveway to pick up speed before releasing the manual clutch so I could pedal start the engine. Engine fired instantly and off I went. She had no power, seemed to be running extremely rich, but my gearing still allowed me to do some hill climbing for about a minute. I turned around and let throttle release to idle and then the engine died. I now cannot get her restarted and the long process of troubleshooting the problem is about to begin.

    Here is my plan of attack:
    1. Check for spark. I prefer to do this at nighttime when it is dark and cooler. I'll ground a spark plug and attach the ignition wire to it and listen for and observe the spark. I'm hoping it is simple as no spark since engine won't start even with a short of starting fluid (ether) into the intake.
    If no spark, I will first cut the kill switch wiring to rule that out and then systmatically replace each component in the system until spark returns. I'm fortunate that I have about 1/2 dozen spare parts from previous builds for each component of the engine. I'll probably replace the Jaguar CDI next and then magneto if that doesn't fix the no spark problem. If I have spark and no start, then I will perform steps under #2.

    2. Pull carb and put a known NT carb on engine and try again if I have spark but no start.
    a. If no start, I will then remove the RSE reed valve and use a conventional intake with stock carb
    b. If that doesn't work, then I'll have to assume I have an airleak somewhere and will check my seals. I'm hoping that my high compression head didn't blow a seal.

    Sometimes I wish things would just work right the first time. I was so excited she fired up instantly and wasn't concerned with it running so rich as that is normal for altitude (over 6000 feet ASL). I have a handful of jets to experiment with but first got to figure out why she isn't running.


  2. srdavo

    srdavo Active Member

    I vote.... fouled sparkplug. :D
  3. Skyliner70cc

    Skyliner70cc Active Member

    Nope, easy stuff ruled out already. Plug was damp but not fouled. It whould be dark enough in about 15 minutes for me to check for spark. I'm thinking my Jaguar CDI only lasted a minute but will know for certain shortly.

    I was so darn excited how easily it started.
  4. BigBlue

    BigBlue Active Member

    I vote...magneto wire.

    AKA: BigBlue
  5. Skyliner70cc

    Skyliner70cc Active Member

    I vote: Jaguar CDI. Anybody know how I can get a warranty repair/replacement?

    NO spark verified when it got dark tonight. A quick swap to OEM CDI cured me of my no spark no start issue. I use Anderson powerpole connectors on all of my rides so a swap out of CDIs was fairly quick and straight forward.

    There are no broken solder welds/wires in the Jaguar CDI. I'm nto happy and hope the warranty comes thru.
  6. BigBlue

    BigBlue Active Member

    Glad U were able to pinpoint - hopefully warranty is honored.

    Good Luck
    AKA: BigBlue
  7. Fabian

    Fabian Well-Known Member

    I was totally confident it wasn't the Rock Solid Engines reed valve
  8. Skyliner70cc

    Skyliner70cc Active Member

    The Jaguar CDI smells like burnt electronics inside.

    JNM motors, to date has ignored my warranty request and I will post a new thread about JNM to get their attention. I'm not impressed by their lack of response.

    I put a better carb than the Dax RT on it (newer carb has adjustable idle mixture airbleed screw) to help fine tune the low end. Jetting w/ 75 main jet is a little lean and will bump it up to an 80. Anxious to put 100 miles or so on the engine so I can determine effects of the reed valve intake and other mods. As of now on this new engine with 22 miles of use, engine is not as powerful as stock slant engine with NT carb and SBP tuned pipe.