57 liter OMC with wet distributor cap

I have a 1988 Chris Craft with

I have a 1988 Chris Craft with a 5.7 OMC. I bought it used a few years ago and have had an ongoing problem with the distributor cap developing a bunch of moisture while its running. I dry the cap off and it works great for a while then it starts acting up and when I look under the cap its all wet. Any ideas?

make sure u have a marine dist

make sure u have a marine distributor on the motor
should have vents on it

"Eric, the obvious things that

"Eric, the obvious things that come to mind are make sure that the distributor cap is not cracked anywhere and seating properly to the distributor. If the oil seal in the shaft on your distributor is leaking it may be letting just enough heat/moisture from the crankcase into the distributor to cause some condensation also.

I would replace the cap, if you have not done so already. If you have, wipe inside of the cap clean with some WD-40 on a clean shop rag (nothing that leaves fibers behind) and dry. Check for leaking hoses, small pinholes or clamps leaking, or even a faulty radiator cap (if you have a fresh water cooling system). That moisture to the engine compartment or distributor has got to have some kind of entry point. When this happens does anything else in the engine compartment have any moisture on it? How long does it take with the engine running to get this to happen?

Gerry"

"Thanks for the responses. Th

"Thanks for the responses. The distributor is a marine unit with two vents and I checked they were clear. The distributor cap is the third one I've tried and they have all done the same thing. There is usually a few inches of water in my bilge (the boat is always at a mooring ball and I do a lot of scuba diving) but the engine is always dry (I have a full dog house plus an overlapping sundeck). I have checked for moisture around the distributor when the problem occurs and all is dry. The problem seems to be worse when the outside air tempurature is on the cold side. Last weekend it took about an hour of running before the problem showed up. I stopped, dryed the cap and carried on for another hour problem free. In the warmer part of the summer it seems to take longer to occur and is usually noticable after running for a couple of hours, stopping for a dive or a spot of fishing and then restarting. What do you think?

Eric"

"Below is something I found on

"Below is something I found on the web...might be worth a shot especially if you have a spare cap?

Over the many years that Universal was building the Atomic 4, they apparently experienced moisture in their distributors as well. In the beginning they tried sealing their distributors, and (in their later years) they provided vents for them. To this day, if you buy a new distributor cap for an early model Atomic 4, it will have a hole near the base approximately 3/16" in diameter. We have no test data to confirm or deny the success of venting a distributor, but you might risk at least one distributor cap by drilling a 1/4" hole near its base. If the hole doesn't cut down on your condensation, it will only have cost you one distributor cap.

If some condensation remains, you might also check with your local dealer to see if there's an electronic ignition kit available for your engine. Getting rid of the points gets rid of most of the problems associated with a bit of moisture in the distributor."

Thanks again for the suggestio

Thanks again for the suggestions. I will try adding a vent hole on one of the spare caps. I am also going to try Gerry's suggestion about the WD40. I'm also going to change the distributor shaft seal once the boat is out of the water for the season. The ignition has already been changed to a Pertronix electronic unit (I'm not a big fan of points) and overall it really works great. If anyone has additional suggestions to try I'd love to hear them. Thanks again.

"you might try a small amount

"you might try a small amount of restricted engine vacuum [ sourced from intake to dist cap ] to keep moisture out of the cap. gm used this method on the LT4 350 motors for years.run a line from the air cleaner to dist,then another line from dist. to intake . this way you get filtered vacuum through cap to remove moisture. you will need to use something like a holley fuel jet to create a restriction so as not to cause an engine miss. the jet needs to go in line close to the vacuum source"

I would assume that the moistu

I would assume that the moisture is coming from the crankcase vapors being forced up through the distributor housing. Check the thermostat to be sure the engine is running hot enough to burn off any moisture and the crankcase ventilation system to be sure it is doing its job

"Thanks for the ideas. This p

"Thanks for the ideas. This past weekend I tried Gerry Corban's suggestion but instead of WD40 I used "Wire Dry" by Gunk. It worked great! First I sprayed inside the cap and wiped the excess off with a clean rag, then I sprayed the cap and wires on the outside (as per manufacturers instructions)and let it all dry (about 20 minutes). I cruised for a couple of hours and then stopped for a scuba dive. When I was ready to leave and before starting the engine I pulled off the cap and it was dry as a bone. I realize this is a temporary solution but around here we only have a month of boating left so it was a great help! We cruised the back harbours for another few hours and the engine ran smooth and steady. Based on what people in this forum have said I will be removing and inspecting the distributor over the winter to replace the seal(s) and whatever O rings there are. In answer to Bob Caskey's remarks; the thermostat was new this spring, the engine runs at a steady 170 degrees and the crankcase vents are clear. If the problem re-emerges next year I'll use the suggestion made by E Wesley which should be relatively easy as there is an unused, currently capped vacuum line on the carb base. Thanks again everyone!!"