Loss of Engine full power, after Overheating and blown headgasket

[pontoonpat]

1989 johnson 60hp...seaweed problem, blocking intake and causing overheating shut-down, while underway. Blown headgasket..replaced, now it seems that engine will not run at full power. checked cylinder firing, by pulling plug wires while underway. Engine hesitation, as each one was pulled and replaced. That, lead me to believe that, cylinders were firing fine. Discovered that, if I depress ignition key and engage choke, engine picks-up alittle speed, but doesn't seem to be running "full-out". Also, pulled and cleaned carbs, still doesn't seem to be running right. Have only run engine, 2hrs. max., since overheating issue. I've noticed two times, engine seemed to briefly start reving real high, like, when out of gear, with no increase in speed. Could it be electronics issue, or still mechanical. Any help, would be Greatly Appreciated. Thanks! Pontoonpat.

 

[Barnacle_Bill]

Re: Loss of Engine full power, after Overheating and blown headgasket

Compression??

 

[pontoonpat]

Re: Loss of Engine full power, after Overheating and blown headgasket

Compression??

I have a compression gauge-set and didn't use it. I thought, since I had spark to the cylinders, that everything was ok. I didn't think it would be compression issue. (Also, bought service manual the very night I posted the issue) I will not be around the boat for a week, to check it out. If it's a compression issue, would it be piston rings or powerhead issue? check both, I, guess? Sorry, Admiral, forgot to thank you for the reply. in-put is much appreciated:joyous: