1991 (B) 70 HP with a miss or something

[Chris73Cobia]

I'm uploading a video so you can see exactly what it's doing. It is about the same in the water and not. You can see in the video it "kicks" intermittently. It seems to smooth out with higher RPM, but at WOT (on the water, not muffs, I know better) it's still audible within the roar. (video to follow, its 54 mb so it's taking it's sweet /-\55 time uploading.

Today I replaced the fuel diaphragm, fuel lines, emptied fuel tank - refilled with fresh gas (plus green stabil). In doing so I eliminated an air leak (air in, no fuel out type leak) but that didn't solve the issue.

Here is a pic of the plugs (new today) top/mid/bot cylinder left to right.

One thing I think could be part of the problem is this plug wire (to the top cylinder)

So what's next ?

 

[jerryjerry05]

Re: 1991 (B) 70 HP with a miss or something

Defiantly replace the plug boot.The plug looks like water fouling.
Do a compression/spark test.Post those results with the movie.
A head gasket can still be leaking water even if the compression is good.I had a bad head gasket and had 150# on all 3 cylinders.Wet plug meant some water was getting in.I removed the head and a small spot was letting water in.J

 

[Chris73Cobia]

Re: 1991 (B) 70 HP with a miss or something

 

[Chris73Cobia]

Re: 1991 (B) 70 HP with a miss or something

Oh I just changed my lower unit oil and there was a "bit" of milkiness. Opening the vent clean oil came out, but when I opened the bottom hole about 1/8th of the fluid was milky, the rest was blue...could that have anything to do with this. Also, how much damage will it do to keep running it the way it is (new plug boot)

 

[Chris73Cobia]

Re: 1991 (B) 70 HP with a miss or something

Sorry i forgot the video, just click the picture and it'll pop and play.

 

[Chris73Cobia]

Re: 1991 (B) 70 HP with a miss or something

Okay, tested the compression and it appears to be 60 PSI on all 3 cylinders.

 

[Chris73Cobia]

Re: 1991 (B) 70 HP with a miss or something

Here are some more pics

There is a bit of corrosion around the bottom coil (where the input wire plugs in), and the boot is torn up on the top (and it doesn't seem like I can just pull out the plug wire and put in a new wire? - any answers on that?)

My compression test above was cold btw, and it starts up like a champ. Also the last few times I put it away I get a few ounces of very oily liquid out of the exhaust (prop) but its not gear lube, its premix (unburnt fuel from the miss or running too rich?)

 

[Chris73Cobia]

Re: 1991 (B) 70 HP with a miss or something

Bump.

 

[jason32038]

Re: 1991 (B) 70 HP with a miss or something

Wrap the plug wire with electrical tape.