Ignition maintainanance? Hotter pugs?

[Chris Simenstad]

Since giving I,m giving my fuel system a thorough going through (purged gas tank, new carburetor, fuel lines, and filters), I have also decided to make sure the other parts of the engine look good.

In terms of other engine "systems" the most mysterious to me is the ignition system.

When I bough the boat back in 2006, I had a mechanic install the MMI/Ignitor electronic ignition kit. It's run great since then: starts easily, and except for my recent fuel problems, has never let me down.

Since then, I have a had a coil failure (I think it was original), and I have also replaced the spark pugs every few years, running either the Autolite 437, or Champion RJ12C.

The last time I did a compression test readings were from 95-105 PSI. The engine uses about 1/2 a quarter between oil changes.

A couple of questions:

- Do I need to replace the distributor cap, rotor, and/or plug wires? My boat is very dry, so I do not think corrosion is a problem, but do these parts wear with electronic ignition?

- I removed an took a look at my plugs (currently the Champions). They didn't look fouled, but were blacker than normal, which could have been due to my flooding carburetor. I have read on this site that someone was running a hotter plug, a NKG XR4. Is there any risk to damaging the engine by running this hotter plug?

Thanks for the insight,
Chris

[sastanley]

Chris,
The RJ12C is already a hotter plug than recommended by Universal and MMI (RJ8C). I tried all kinds of different plugs and temps and hunted around and wasted time and $$ at various parts places, and so far am having the best and smoothest running with the good ol' RJ8C's, which I can readily get at Walmart.

I have electronic ignition too and I replace the rotor and cap every few years, but not annually like I probably would if replacing the points/condenser. They can 'wear' from arcing and stuff inside the cap. Any black stuff indicates some arcing inside the cap, and the rotor contact at the top spins around and does wear a little bit.

Plug wires are a slightly different story, but over time can get brittle and crack and 'bleed' spark. The best way to check this is to run the engine in the pitch black and see if you see any arcing on the wires (I've seen some on car engines that look like that old "electricity ball" from Radio Shack!)...or, if you don't know how old they are, I might add them to my next MMI order.

Post up a picture of your plugs! With good compression numbers like that they should be a nice tan color, unless you are getting some oil thru the oil rings, but 1/2 quart doesn't sound excessive to me! I rotate my plugs during the season..I struggle a little bit to keep #4 from fouling due to excessive cylinder wall wear from past water intrusion (keep those intakes closed on extended crank events, and find out what is keeping it from firing up quickly, which it should!

[JOHN COOKSON]

Also service the advance. It's under the breaker plate in the distributor.
If the various parts are not to far gone you could keep them as spares on the boat. If they are still serviceable they should get you home if something fails.

TRUE GRIT

[sastanley]

Originally Posted by JOHN COOKSON

Also service the advance. It's under the breaker plate in the distributor.
If the various parts are not to far gone you could keep them as spares on the boat. If they are still serviceable they should get you home if something fails.

TRUE GRIT

John, thanks for that..Since I forgot to service my own advance weights and they froze up this spring, it is nice that another member remembered to remind me and other members!

[ndutton]

Originally Posted by Chris Simenstad

When I bough the boat back in 2006, I had a mechanic install the MMI/Ignitor electronic ignition kit. It's run great since then: starts easily, and except for my recent fuel problems, has never let me down.

Since then, I have a had a coil failure (I think it was original)

Yup, why am I not surprised? Please describe the replacement coil, where you sourced it, etc.

[Chris Simenstad]

Thanks everyone for the replies.

I'll post photos of the spark plugs later in the weekend. Looking at my maintained logs, I have not changed them since 2013

I have a spare rotor that came with the boat, but the engine had points then. Is the rotor any different with the electronic ignition? I see the igniter rotor on the Moyer site.

The coil failed in 2009. The engine would shut off, like someone turned the key, when I ran at cruising speed and then throttled down to idle. I bought two from Moyer, and still have the spare. My current shutdowns sound different, more like fuel starvation.