help with one last problem

[RRitt]

I have one problem standing between me and PWO (Perfect Working Order). Hopefully some of the more knowledgeable commentors can save me a ton of time by identifying where to look and/or what to do or not do. Presently I am considering swapping the CDI/Coil assembly between port & starboard engines to see if problem follows the coils.<br /><br />My port engine doesn't like to start if the battery is not fully charged. If the battery is completely charged then it starts on first spark. If the battery is even the slightest bit low then it won't start. The starter turns with good speed, but it just doesn't fire. The starboard engine fires right up off same battery. Compression check on all cylinders is within 5PSI on both motors.<br /><br />What, why, where, how?<br /><br />TIA

 

[eurolarva]

Re: help with one last problem

I would swap starters first. Even though you mentioned that the starters spin about the same if one is a bit slower it could explain it not starting. If swapping the starters fixes the problem take the weak starter apart and clean it and put it back together again and re try.

 

[RRitt]

Re: help with one last problem

I'm 99.99% sure that it's not the starter. I'm also 99.99% sure that the problem is a lack of spark. In order to spark, the port engine needs the battery to be at 100% maximum voltage. Even 1 hour of stereo is enough to cause non-sparking. By comparison, the starboard engine sparks with any battery voltage.