Metal shavings in Distributor Cap

[chopperdog]

1988 Bayliner
With OMC 3.0L 4 cyl.

Boat has been running well.
Went to warm it up today before taking it out.
It was running rough, and loud. The engine was vibrating, like it was out of balance, like maybe it was misfiring.
The timing has been fine until now.

I pulled the plugs, they looked clean. I checked connections at the coil, spark plug wires. I checked the carb, choke.

INTERESTING thing, is that I found metal shavings in the Distributor cap. These were clean, fine metal shavings. A pile of them, about the size of 2 quarters stacked together. A pretty good amount. I cleaned out the distributor, thinking that maybe the filings were causing a short.

Problem is still there.

Are the filings a clue as to my problem?

Thanks,

Chopperdog

 

[Gary H NC]

Re: Metal shavings in Distributor Cap

How did the inside of the cap and the tip of the rotor look?
Does it look like it was hitting the contacts inside the cap?

 

[chopperdog]

Re: Metal shavings in Distributor Cap

The rotor tip appears to be brass, and is in good shape. It is scratched a little, so maybe the shavings are from the rotor tip and contacts.

I just pulled the distributor. The shaft looks good, with all the gear teeth in good shape.

Another possibility could be fuel.
We had a huge rain storm yesterday. The gas here contains ethanol.
I run the boat about once a week, but have not had it out in awhile, so the gas is a couple months old.

Could this be the problem?
Can I fix this with a fuel boost additive?

 

[chopperdog]

Re: Metal shavings in Distributor Cap

Just to clarify the symptoms.

It is a little difficult to start, like maybe 3 seconds. Once it does, it runs as though a cylinder isn't firing. It's almost like it's getting ready to backfire.

I felt the oil fill hole on top of the valve cover, and there is quite a bit of air coming out. It had a complete valve job a year ago, and has run fine since.

Thanks for any help.

 

[bds85466]

Re: Metal shavings in Distributor Cap

doubt the shavings themselves are causing the major problem, may be a symptom of another problem though. is the cap seated correctly? is there any wobble in it?

 

[chopperdog]

Re: Metal shavings in Distributor Cap

Cap seems tight.
I've never seen the cap wobble. I run the engine while observing it quite often, just making sure things are as they should be.
I just can't figure it out.

 

[Fishermark]

Re: Metal shavings in Distributor Cap

Check your compression and do a complete tune up.

If you don't have a fuel / water separater, go ahead and install one.

No - don't bother with the fuel additive.

 

[rodbolt]

Re: Metal shavings in Distributor Cap

if its a point type distributer check the mechanical advance set up. sometimes the springs let go and bad things happen.

 

[sethjon]

Re: Metal shavings in Distributor Cap

2 month old gas is fine. Was the metal filings brass? If so, it has to be either rotor or the cap itself?