1978 Mercury 6 1150 115 HP, Bits of stuff in Distributor cap???

Howdy guys! I have a 1975 Witch Craft with a 1978 1150 115 HP 6 cyl. Last time we had it out the motor started to run rough and was hard to restart, luckily we were at the boat dock at the end of our day when this happened. When I removed the distributor cap there was quite a bit of bits of particles, so what does this mean? I tested with a magnet to see if it was metal particles and some were. I cleaned it all out real good and also removed the plugs and cleaned them too, put it all back together and started it up, it ran good, but I'm thinking something is going south in the distributor and don't want to get stranded on the lake broken down. So does this mean I'm going to need another distributor or can I replace parts (if available) and rebuild the old one??? Could it be that a distributor bearing is going bad, or what??? Thanks and I'm happy to join this forum!!!

Definitely time to tear down that distributor before it destroys itself! My experience with that was on my 1350, Many Moons ago. The steel snap ring that holds the lower rotor shaft bearing into the distributor housing had corroded and finally broken. These broken bits circulated around the inside of the distributor cap like a Cuisinart and eventually tore out the trigger pickup, ruining the entire distributor housing (since the trigger cannot be removed without destroying it).

Fortunately I was able to find a good used distributor at the local outboard wrecking yard for $50. Not gonna find one that cheap anymore!

Before you pull everything apart, first remove the 5/16"-headed-bolt and metal dist. pulley cover. Find the arrow that's cast into one of the ribs on the dist. pulley. Rotate the flywheel until the arrow is pointing at Dead-Center of the crankshaft. You should find that (3) vertical punch marks on the circumference of the flywheel align with the arrow. If things don't line up quite like that, be sure to note the current alignment so you can put it back the same way.

Providing, that is, that the motor is running OK the way it is, the Max Spark Advance is properly set, and the mis-alignment is no more than 1/2-tooth-off. The manual says that is OK.

Once you remove the distributor, bend down the locking tabs on the top and the top unscrews (right-hand threads). Pry out the upper bearing with a "tweaker" screwdriver thru the holes in the side of the distributor housing.

There is a nut that holds the rotor shaft/spacer in place. I found that a deep 3/4" socket works well for that task. Hold the rotor in a gloved hand and the retaining nut has right-hand threads.

GENTLY tap the rotor/shaft assy out the bottom while holding the copper trigger disk. A plastic mallet works well for this task. Mark the trigger disk so you'll know which way points outside. It's stamped from the factory, but the stamping may have deteriorated over the years. Note that the trigger is keyed to the rotor for proper alignment.

Word of caution: DO NOT allow the trigger disk to be forced down upon the trigger pickup while you're tapping the rotor out the bottom, as you may break the trigger and render the dist. housing useless. Sometimes the disk "welds" itself to the rotor shaft via corrosion, so be careful if things don't slide smoothly apart.

Once the rotor is pulled, disk out-of-the-way, the only thing left is the lower bearing. Remove the snap ring and drive out the bearing from above, using a suitable drift.

Assembly is the reverse of disassembly. Be sure to replace the snap ring, regardless of its condition. It's an inexpensive part that can cause $300+ worth of destruction.

Note I'm typing this from memory, might have left out a detail or two. Best to consult your manual or stop and ask questions if it's not working for you.

You can pull up a parts diagram here for your motor, based on its serial #.

HTH............ed

Thank you for your reply!! Inside the distributor is a lot of corrosion and I would like to clean it out so what is the best cleaner (if there is one) and method to do it?? I'm thinking of using my Dremel with a wire brush attachment, because that corrosion also falls into the cap. It is hard for me to believe that the aftermarket companies like MSD, Mallory, Accel, Mercury ect haven't offered a new improved distributor like they do for car engines!!! Come on you aftermarket manufacturers!!! Yes I know already that they don't, Ohh well!!! I will need some help getting parts for this thing and any suggestions of where and who would be very much appreciated and thanks again for your help!!!

Here's a distributor diagram for the last run of 115's with distributor:

http://www.marineengine.com/parts/m...hru-5430526-usa/distributor-housing-and-rotor

This may or may not be within the range of your motor's serial # but the distributor parts will be the same.

Far as cleanup goes, if you're very careful with the Dremel not to gouge the body of the dist. cap, a wire wheel would be handy for cleaning the brass contacts. You can pull the carbon contact and spring out of the cap with a winding motion. I've had good luck cleaning out the cap with carb cleaner but any equivalent solvent should do the job.

I wouldn't use the Dremel on the distributor body itself, far too easy to slip and ruin the trigger pickup. A "Gordon" toothbrush-type of wire brush would do a good job but be really careful around the potted material and trigger.

And there is an aftermarket, improved distributor body from CDI Electronics, you'll note the OEM and CDI parts on the diagram.

So instead of $467 for the OEM part, the CDI part is ONLY $386! Thus my cautions about handling the dist. body. You've got a working one, let's keep it that way!

You can order parts at your dlr or right here, off the parts diagram.

Cheers.......ed

My experience tells me that if there is a demand then aftermarket parts will be available.---------No demand on original quality parts then no one is going to set up and make this stuff to sell a few a year !