Moisture Inside Distributor Cap - HELP!

[Sailorbanker]

Hi there. Have a 1986 32 Aft cabin with 305 Crusaders. Have owned boat for three years and we love it! It was very well maintained and upgraded by prior owners.

We have added about 100 hours in the last 3 years. However, due to busy schedules, we used it very little in the past six months. My port engine started developing a ton of moisture inside the distributor cap. Replaced it (including new seal), added Wire dry/WD40, and it ran fine. Yet after a few weeks pulled the cap and was completely corroded. Again cleaned it, added wire dry/wd-40; Ran for a bit and died. Cap was full of moisture.

Ideas???

Never had a problem until recently.
Anyone using vented caps and if so, where can I get them? Thinking of venting the cap to a vacuum in the carburetor.

HELP!!!!!

[waybomb]

This is a points distributor? I would not take a points ignition system and vent them to a carburetor! Seems to me you may get an occasional mini-BOOM. Not good in a boat.

Moisture only collects on surfaces colder than dew point. Having said that, why is this one distributor colder than other things, and, where is all this moisture coming from? Do you have a wet bilge? A cooling system leak? Is the engine oil ok? Are the wires to the points sealed;the seal is almost 30 years old now. Are you using the exact correct cap? Is there a crack or hole in the distributor body? If it is this corroded, does the advance mechanism work or is it frozen by rust?

I don't have an answer but if it were me, I'd be checking the things I've questioned, starting with how sealed is the interior of the distributor.

[g36]

is this happening now or summertime? dont know where you are located. i would try and have a dry bilge as suggested and if it gets below freezing a bilge heater would at least keep the engine compartment warmer and more consistant temp.
agree any gas fumes exposed to some kind of arc would not be a good thing.

[Sailorbanker]

they have been changed to electronic ignition. bilges are bone dry: we keep the boat in the San Juan Islands, WA and both the boat and bilge are heated to about 60 degrees during winter.

oil is changed every 25 hours; caps are brand new after the first incident when started accumulating moisture. no coolant leaks. first time it happened was during the summer.

hmmm, looks like a worn seal.

thanks!