I still have some condensation under a distributor cap. Had this issue on the other engine last year. I've had one suggestion to drill two very small holes in the cap, one between two points the other in the top to allow the moisture to evaporate. Has anyone hear of this or done this?
Protected trouble light in the bilge.
Drilling a hole in your distributor cap would be a very bad idea.
A vented cap is an explosion hazard in a boat as a spark escaping from the cap could ignite fuel vapors in the engine room.
From my experience with Mallory distributors, the proper marine distributor has a vent in the bowl covered by a protective screen and uses a non-vented cap (e.g. Mallory 221B). If you have an older model Commander, it's possible the distributor does not have a bowl vent. That was the case with my 1967 427's (Mallory YL type distributor). I had them re-built by Mallory some 5+ years ago and they came back with the bowl vent. Mallory is now owned by MSD Ignition and I'm not sure if they offer the rebuild service anymore.
Even with the bowl vent, I experience some condensation inside the cap from time to time. That plus the general finicky nature of the 221B caps means that I usually have to replace a cap or two once a season. I keep two spares on board for this reason.
Russel- Repeating that this is a very bad idea. All of our marine electrical parts are spark protected. That is why we do not use automotive parts-alternators, solenoids-in our boats. Unlike our cars, gas fumes in our engine room do not dissipate into the atmosphere without mechanical assistance. The fumes from 1 cup of gasoline have the explosive force of 16 sticks of dynamite. Not the place you want to introduce a stray spark.
Point taken guys. when it was suggested as a solution it didn't seam right. In theory I understand why someone would do this but....
I'm going to gently clean the bowl vent.
thank you very much.
My experience is that the condensation happened most when the morning was cooler then warmed causing the engine to sweat. It still does it from time to time so I put a little rainx on inside of cap. Another cure could be to put a low wattage light near the cap.
I've listened to you and not done hole. Today FINALLY had another run after going over the fuel and ignition again. Nice test ... engines ran fine... several accelerations to 2500 rpm. Then back to idle. Last run up to 3000... Then slowed to idle... and stall! Of course this happened as going under a rail bridge when the tide was coming in so the current was running pretty good.
Made it through on one engine without incident, dropped the hook. No issues with the distributor cap. Found a small amount of fuel at the side of the carb. Guessing it flooded. Wiped it up. Fired the engine, it took a little cranking but then back to the dock without further incident. Trying again in the week.
I had a float stick on the carb that would cause it to run fine at higher power but wanted to die below 1500 rpm. Check for fuel dumping down the throat from the vents.
I have tried this yet but,I was thinking a tiny bag of desiccant inside the cap or base. Something like 1x2inch?
I had an AFB that the throttle shaft area was cracked on the body. It would not leak while running but as soon as the engine was shut off it would leak onto the intake.