What should it look like?

[55'Fleetwin7.5]

I pulled my plugs and took a look into the cylinder... The top of the piston is BLACK and covered with small bumps... is this OK? Normal? what is the deal?

I am taking it out Sunday... If it needs cleaning... how is it done?

 

[jbjennings]

Re: What should it look like?

I think the black piston tops are no problem. Just carbon. You might want to look at the FAQ on decarbonizing your motor using some sea foam. Personally, I'd just run it with 24:1 for a while and then decarb it when you know it's running perfect.
I'm not sure about the "bumps" on the piston. that sounds a little odd. Hopefully someone more knowledgeable than I will give you some ideas on those bumps.
JBJ