Bad mixture? Help

[mecelprimo]

Motor was running rough
And this is what I found, what is all that on the top of the Pistons

 

[racerone]

Running way too hot.-----Due to preignition.----Lugging with too much pitch on prop.----Timing too far advanced.----Water pump ignored ETC , etc.----Yes lean on oil too.

 

[Redbarron%%]

What you see is melted pistons.

 

[jerryjerry05]

What octane fuel?
Timing set wrong?
Oil mix, 50-1
All three at once, wow.

 

[mecelprimo]

What octane fuel?
Timing set wrong?
Oil mix, 50-1
All three at once, wow.

93 or 87 octane
And the oil mix yes 50:1

 

[Scott Danforth]

when was the last time you went thru the cooling system or maintained the fuel system?

the melted pistons mean rebuild time.

 

[The Force power]

93 or 87 octane
And the oil mix yes 50:1

That leaves you;
- Water temp.
- Timing
- RPMs @ WOT

 

[Scott Danforth]

That leaves you;
- Water temp.
- Timing
- RPMs @ WOT

or running lean from crud in the fuel system
or lugging load from too much pitch on the prop.

 

[jerryjerry05]

Sucking air someplace?

 

[las]

Wow that looks bad!
Cylinder wall doesn't look to bad actually, cooling could be ok? So maybe a lean condition on 1 and 3? Possibly combined with too much advance and "heavy lifting"
But by the looks of it, it must have sounded terrible some time before running rough

 

[mecelprimo]

Wow that looks bad!
Cylinder wall doesn't look to bad actually, cooling could be ok? So maybe a lean condition on 1 and 3? Possibly combined with too much advance and "heavy lifting"
But by the looks of it, it must have sounded terrible some time before running rough

yeah cylinder wall are ok, cooling system is good also fuel system, I think the issue was the timing

 

[Scott Danforth]

either way, if you drop a bore gauge in there, you may find the bores are no longer round, however egg shaped.