View Full Version : 89 190 Not Burning All Fuel

05-23-2013, 09:21 AM
So my summer is sucking at the start. Boat ran fine for a day then died. Carb was rebuilt and is functioning properly but the boat is still not burning fuel well. Mechanic is doing a leak down test. He mentioned the other day he heard something in the motor that sounded like a valve not closing correctly and he doesn't want to give me the boat if it is not running perfectly.

He tried to explain it to me but I build networks, not motors.

Is there anything I should make him aware of based on any of your experiences?

Here is the text of his email - "The carb is performing properly now, but it is not changing the way the engine running. It will only stay running with lots of fuel and throttle.
I am going to test compression and cylinder leakage now. There is way too much unburnt fuel coming out the exhaust. "

Thanks for the help.

05-23-2013, 09:34 AM
Unburnt fuel makes me think that you have one or more spark plugs that aren't firing. So bad plugs, wires or distributor, or some combination of, would be my guess. Plugs and wires are relatively cheap, have they been replaced recently? Are the wires in correct firing order? Loose wires? Bad coil? Just some ideas.

05-24-2013, 10:27 AM
So it looks like it is running OK now after the third sonic cleaning and rebuild but now for the new issue.

From the mechanic:

"Compression is low on all cylinders, some worse than others ranging from 120lbs to 160lbs.
But the leak down test did not do good either. All cylinders leak more than 30%."

Am I getting to the rebuild point yet? Any thoughts on what I should look at next? Thanks everyone. I know it is frustrating talking to someone who doesn't know anything about these motors. Looks like I am about to have a project to learn though.