One very clean cylinder head and plug

[Odawg753]

Took spark plugs out from last season and top cylinder looked BRAND NEW. Did research n read water may be coming in. I took head off, but was dumb and didn't do compression test prior and these were results, head of top cylinder was very clean but top of piston had good amount of carbon. Now question is if there is no spark in a cylinder would it still be oily in the cylinder since nothing is burning? And if there was spark but no fuel wouldnt the cylinder have friend?

 

[racerone]

You might start with a model # of your motor.-------Make no assumptions.

 

[Odawg753]

 

[Sea Rider]

If that's a 2 strokes engine don't dream about finding all piston heads and internal cylinder head to be even in color, some cylinders darkens, carbons more than others. 2 strokes are disgustingly filthy engines LOL!! Pics were shot as soon cylinder head was disassembled or have been lightly cleaned for presentation?

If water comes in cylinder and depending on how much, engine will miss at speed and spark plug will be foung tip rusted.

Happy Boating

 

[Faztbullet]

That engine has been into as #3 and #5 are .020 OS. I suspect low compression on #1 or reed,ignition issue

 

[F_R]

That engine has been into as #3 and #5 are .020 OS. I suspect low compression on #1 or reed,ignition issue

Yeah, I was wondering why the top one has four prick punch marks like it once was in #4 cylinder. Suspicious, to say the least.

 

[Odawg753]

If that's a 2 strokes engine don't dream about finding all piston heads and internal cylinder head to be even in color, some cylinders darkens, carbons more than others. 2 strokes are disgustingly filthy engines LOL!! Pics were shot as soon cylinder head was disassembled or have been lightly cleaned for presentation?

If water comes in cylinder and depending on how much, engine will miss at speed and spark plug will be foung tip rusted.

Happy Boating

No cleaning at all, that's how it was. Took carb apart looks good. Just gotta put it back together n test compression and spark. I just feel it it was a spark issue it would be very oily

 

[racerone]

Why would it be oily ?-----That cylinder would simply blow the oil / fuel mixture right through like it was running normally.

 

[Odawg753]

Why would it be oily ?-----That cylinder would simply blow the oil / fuel mixture right through like it was running normally.

Because it wouldn't be burning, idk just my thought process. I'll advise tomorrow

 

[Rustywrench]

Looks like water on #1 cylinder to me. That family of engines has a history of that. They can be fixed, but would require a rebuild & pressure test the block to confirm leaking water on #1 cylinder. Only leakage on #1 & sometimes #2 can be repaired. It does look like some hanky pansy has occurred here since top of the piston would be clean too under normal circumstances.

 

[Odawg753]

Hey guys all put back together swapped bottom coil with top and right away while switching them I noticed the coil for that cylinder had a burn mark and a chip in back of it, so I swapped and started and instantly heard sparking so I look n the coil that I moved to bottom was arcing against the aluminum behind it. So looks like it was a spark issue, thanks guys!!