Engine coming apart? Starflite 85 has balls on plugs.

[Dewpoint]

Hello, Two separate trips now, twice on one day, I will be powering up for plane, and the engine will start to misfire badly. I stop, and pull the plugs and I find these balls of something on my plugs. I clear them out of the gap and continue on. There doesn't really seem to have a rhyme or reason as to when it happens but I always notice it when powering up. Happened on cylinders 1 and 4. The balls are hard like carbon or a metal and my screwdriver I used to clear the plug has a magnetic end that the ball stuck to so I am thinking it's a ferrous metal. I can smash it between my fingers and it doesn't leave a grease behind.

I just very recently put these new NGK plugs in so maybe I'll put new plugs from the old brand back in and see what happens? I hope I haven't effed up the oiling situation somehow and ruined my motor?! I have a wealth of experience with car engines and race carrs and such and I have never actually encountered this before. Any advice from you boating masters?

1974 Evinrude Starflite 85hp all original engine as far as I know.

 

[F_R]

If you had not said they are magnetic, I would have said it is loose carbon flaking off the cylinder tops and / or heads. But if it is magnetic I suppose you ought to at least pull the bypass covers for a quick inspection. How does the compression check out?

 

[racerone]

I am guessing wrist pin bearings.

 

[jimmbo]

. I can smash it between my fingers and it doesn't leave a grease behind.

By 'smashing' does it crumble?

 

[Dewpoint]

Sorry jimmbo, that's a typo, I can not smash them. They are very hard and trying to cut them with a razor blade just sends them flying. I got a little borescope camera and nothing looks bad but it's a crap camera with terrible detail so... I'm going to put in the old champion brand plugs and see. Going to think about tearing the carbs off and check those but gaskets are expensive.

They are not magnetic after all. and googling around I found a similar issue called "splash fouled". This might be the problem diagnosis but not sure what the main problem is yet.

 

[ricohman]

I have seen these before in old two stroke outboards. And more recently on a newer E-TEC. Some were much larger than what you have pictured.
My engineering buddy at the local heavy oil upgrader states they are from fuel and oil deposits. When I told him they were probably metal he crushed one with a hammer and told me to use my magnet. Sure enough after being smashed to bits the magnet had no effect.

 

[F_R]

Back to carbon fouling. But take the bypass covers off for a peek. It is not all that hard to do. If the pistons and everything look OK, pull the heads and scrape the carbon out. I guess somebody will say use Engine Cleaner and I won't argue. Try it if you want. Personally I think it is over rated.

 

[fireman57]

Use only Champion plugs as these engines were designed around them.

 

[jimmbo]

I remember my friend outboard getting crap in the plug gap years ago. Back in the early 1980s we could still get leaded gasoline, and plug issues were much more common then.

 

[F_R]

I remember my friend outboard getting crap in the plug gap years ago. Back in the early 1980s we could still get leaded gasoline, and plug issues were much more common then.

You got that right. In fact, if you look at an old Evinrude factory service manual, pulling the head and cleaning the carbon out was part of a "Tune-Up" job. And they usually needed it. Unleaded gas and TC-W3 oil isn't all that bad if we look at the big picture.

 

[oldboat1]

Dewpoint, what are you running in the tanks? Particular additive you've been using? Guess you could find some of those issues with extensive trolling, but seems extensive.