Project Boat and Mod motors

[Guest]

Magneto setup

I have a mag test bench that can run a Mercury magneto to 10,000 RPM. What I have found is that after market points don't always meet the Mercury spring tension requirements. A mag I did a few weeks back for a friend would not produce a good consistent spark when I tested it before disassembly. As it turns out the spring tension was only in the 20 oz. range where the Mercury points normally run just under 40 oz. tension. I can post some photos of the tools to set a mag up.

Alan

[1100-one]

I have a mag test bench that can run a Mercury magneto to 10,000 RPM. What I have found is that after market points don't always meet the Mercury spring tension requirements. A mag I did a few weeks back for a friend would not produce a good consistent spark when I tested it before disassembly. As it turns out the spring tension was only in the 20 oz. range where the Mercury points normally run just under 40 oz. tension. I can post some photos of the tools to set a mag up.

Alan

Very true Alan. We found that out years ago with the after market points. We even tried to crimp the arm if you will with a pliers to gain tension but didnt work at all. Went to mercury points and had no more issues.

[Larry M]

Try timing it on another cylinder. Go thru the procedure just like you do on number one. This will tell if something is wrong with the number 1 cam lobe. I agree a weak spring will give you problems but not just setting up the timing on a non running motor. I have even used double springs on the points. Like Kevin said double check the point gap.

Larry Mac

[David_L6]

375 is way high. Unless I am missing something here, .235 is stock. I think on a mod motor roughly .285 is about as high as you want to go. I know some guys run more but? How the halibut do you even start it with that much advance. I wouldn't want to rope it, I can feel the stinging now. Are you sure this is what you have?
kk

A lot of people run in their timing up in that range. The short period of time that I had a D (40), I ran it at .375. I generally ran .350 on my C motors although I have tried them as high as .385. I ran my E at .320.

[krazy karl]

Sorry I caused confusion, I had my numbers all mixed up. I haven't timed a Merc in awhile.
kk

[Guest]

Merc point gap

When I install new points in a mercury mag I set them tight at.010 inches and used points at .009". Always make sure that the lubrication wick is set correctly. Lots of folks don't install them and that's a sure way to wear the points and cam.

Corrected typo on point setting! Old age LOL

Alan

[ZUL8TR]

Gap

When I install new points in a mercury mag I set them tight at.010 inches and used points at .090". Always make sure that the lubrication wick is set correctly. Lots of folks don't install them and that's a sure way to wear the points and cam.

Alan

I think you mean 0.009" on used points.

[Art K]

If you run the progressive linkage where you run the swinging mag you can go very high with the timing over .400 if you have the sense to back off on the throttle slightly as you start down the straightaway. helps acceleration. We are now running an Electromotive ignition system that you you program to back off the timing as rpms increase down the straighaway. Have it on 3 engines, trouble free. Would never run a Mag. again.
Art K

[blueskyracer]

I will be shipping my Mags to Alan for Physical and check over.. He has offered to help me out

[krazy karl]

"Old age LOL"

As per my post, I resemble that statement too.

kk

[blueskyracer]

"Old age LOL"

As per my post, I resemble that statement too.

kk

A lot of us have the age problem.. We have to make constant lists or we forget!!!!

[form-e one]

aaa boat raceing... the never ending learning curve,,hehe

[blueskyracer]

aaa boat raceing... the never ending learning curve,,hehe

More like the frustration curve.. I guess we have to live for that one moment every 5 years were it all comes together and works