2001 Johnson 70 Compression 140,120,88

[bambooi]

Engine: JPL70SIS
What could be the next steps and any ideas on cost?

The boat was occasionally bogging down and not running correctly.

I also check the spark and it clears 7/16 fine. I got this boat from my father in law which has been sitting for awhile in the water. I just pulled it out of the water 1 weeks ago. I also looked at the carbs and the high speed orifices looked cleaned. I used a small screw driver to take them out, but this doesn't mean that the other passages are clean.

Based on all that what is the best steps forward? The engine is on a 2000 16' Sea Fox Center Console.

 

[racerone]

Remove the cylinder head for inspection.-----Just a few bolts and it is off.-------Sounds like it needs to be rebuilt.--------If you can do it yourself it is affordable.

 

[bambooi]

I took the head off. I see a bad piston and score cylinder waters. Does it look like a blown HG led to this? Look around the head gasket, cleanish head, and around the top of the cylinder. Should I just get a machine shop to bore it out and put bigger pistons in? I'm not sure if that is a bad head gasket or was it a lean condition. Are there any online guides to removing the engine? Thank you in advance.

 

[racerone]

Not caused by a blown head gasket..---wrong prop perhaps ?---Overheating ?---Oil injection issues.----Preignition perhaps.

 

[bambooi]

When I took the carbs apart I noticed the bowls were not set level when flipped upside down... Therefore maybe not enough fuel when WOT? Their angle were maybe 20/30 degrees higher