TOPIC: mark 75 progress

Hey all,

A while back i posted about finding a mark 75 for $80. I have been working my butt off and finally am getting close to firing it. I borrowed a set of ring compressors and installed new rings, new seals, and all new gaskets. I have the tower bolted back up to the midsection and now i am onto setting up the distributor and have some questions.

The same guy I borrowed the ring compressors from also let me borrow his point synch plate, but he did not have the pointer. I can make a pointer, but i was wondering if it mattered where the pointer was attached in relation to the distributor shaft? From what i see, i can just rotate the synch plate to any position, as long as i keep it in exactly the same place after i set the 1st set of points. Am i thinking correctly? This leads me to my next question, which set of points is actually the 1st set? When looking at the distributor, from the point side, the two points wires are coming out of the bottom and the breather is on the right, are the top or bottom points the 1st set? from what i can see i think it is top?

sorry for the long post and all the questions. I want to get this right if possible. Currently the points only have about a .003 gap, which seems very small to me.

Thanks!
Scott

Conrad (milkdud) and the gang went into great detail on how to set up the dual points distributors for me around four years ago, I did an "Advanced Search" and went back to find it for you Scott;
www.fiberglassics.com/fiberglassics-forums/home/mercury-outpost/63-merc-1000-dist-ignition-problem#28501
It was on a Merc1000, but I believe the procedure would be the same, Hope this helps.

Thanks mark for the info. I got the points set up tonight and i think they should be good to go.

now that i have the distibutor off, i am planning to replace the bearings. I was able to remove all of the bearings except the very top one under the belt pulley. Im not 100% sure how to remove this bearing and i dont want to wreck anything. It looks like there are (3) metal tabs that may need to be bent over in order to get the bearing out, but im not positive.

Can anyone give me some insight?

Thanks!
Scott

Its been several years since Ive taken that top bering out. I believe you are correct that the tabs are pushed back so the cap can be screwed off exposing the bearing. If I remember right the top bearing is different that the other ones. There are 3 lower ones (two on dist cam) and that top one your working on. The 3 lower ones are the same. Inspect your points cam for wear too. If the lobes are wore down it can be a good idea to replace it. Once the get rounded over they don't set up very well. I might have an extra new points cam if you need it.

Have fun. they are amazing engines once running.

I'm working on one also. Custom.

Good point; they'll idle pretty rough if the points cam is excessively worn.

Currently listed on eBay is a really cheap, new cam in OEM packaging:

Here's a parts diagram for the distributor, a bit hard to read but still useable:

www.marineengine.com/parts/mercury-mark-outboard-parts/mark-75/all/distributor-assembly-complete

HTH.......ed

easiest way to set the points is to use a dwell meter and spin them with a drill.