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Discussion Starter · #1 · (Edited)
Things I've checked and confirmed working:

BAS (Bank Angle Sensor / Tip Sensor) - Jumped (Pin 1 and 3) / Confirmed by un-jumping and trying to start in neutral. Fuel pump does not prime, Does not crank unless jumped.

Kickstand Switch - Jumped (Pin 1 and 2) / Confirmed by un-jumping, and trying to start in gear with clutch pulled. Does not crank unless jumped.

Neutral Safety Switch - Confirmed by shifting into neutral and seeing the green N on the cluster.

Clutch Switch - Confirmed by trying to start in gear with clutch pulled in. Cranks, but no start/spark. It will not try to crank with clutch lever not pulled in.

Injectors + Fuel - Confirmed by removing airbox and physically watching the bottom 4 injectors spray while it tries to start. (Top 4 injectors only active above certain RPM)

Fuses + Relays - All good, including the 20amp by the battery. Also the diode in the fuse box up front is good.

ECM / ECU (Computer) - Fuel pump primes, but I did replace it with a known working one and still no spark. Only code is 34 (Servo motor for the exhaust valve). Service manual says this will not cause a no start condition.

VSS (Vehicle Speed Sensor) - Good, shows +MPH on cluster while rolling in neutral.

Pulse Generator (CKP Sensor) - I removed this sensor from the clutch cover, checked continuity while placing metal in front of the magnet and saw it fluctuating. Reinstalled, and tested for continuity back to the ECU which appeared good. (This and the CKP sensor are hard to test as they are HALL sensors with a square signal that my multimeter cannot read) I have since replaced this sensor with a brand new one from Honda. Service manual shows this sensor should be above .7v AC when cranking which both sensors showed.

Camshaft Position Sensor (CMP Sensor) - I removed this sensor from the left of the head by the header and found like 2 or 3 tiny metal shavings on it. (Apparently common due to the cam gear clearance being so close and can expand/move due to heat.) Cleaned off and reinstalled, and checked continuity while cranking and saw it fluctuating within range. I have yet to replace this sensor as it's on backorder from Honda... However the Factory Service Manual shows this as playing no role in ignition spark. Only fuel. Service manual shows this sensor should be above .7v AC when cranking which this sensor does.

❌ Spark - No spark confirmed by grounding plug on frame while trying to start. Plugs look practically brand new, along with boots. Have tried swapping plugs and boots around.
I do have 12 volts at all the ignition coils (spark plug boots). So I am pretty sure this rules out any of the safety switches. The ECM is just not grounding them.

  • I have replaced all the spark plugs with new NGK IMR9C-9HES plugs with no luck.
  • I have swapped the ignition coil (spark plug boots) around, and tested all 4 of their primary and secondary resistances which were in spec.
  • I have checked for continuity across the entire ignition system portion of the harness. (ECM grounds, ignition coil grounds, etc.) All good.
  • I am repeatedly told to check the kill switch, and I took it apart and it's in great shape and I do have 12v at the ignition coils when switched on.

Main concerns:
  • HESD light is on, although the unit is plugged in. Service manual says that it would not cause a no start condition, but I've read on the forums otherwise.
  • Same with code 34 for the exhaust servo motor (EGCV / Exhaust Gas Control Valve) but service manual also says this would also not cause a no start condition.
  • I HAVE seen spark on this bike well testing around, but only one spark, per ~10 revolutions about 3-4 times total in weeks of testing, and could not repeat this or get it to spark since.

What else could there be?

PS: Here is a link to my discussion over on No spark, ‘07 which this post is a summary of all the testing

13 Posts
Discussion Starter · #2 ·
Just got a new cam sensor in... (Not crank sensor).. Will update shortly
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