Im cant figure this out...

Well memorial day i started up the boat let it warm up a little, and then she started smoking alot more then usual so i lifted the box and checked everything out, motor ran silent, all the hoses that should be cold were cold. so we kept going. later on the way back the tempature guage jump way up to 220 then back down to 130 and it just kept doing this. later that night i tested the thermostat and it was sticking so i already ordered the new one. i dropped the boat in today without the thermostat to check things out, and board, and everything ran great except it still smoked, and the tempature guage was bouncing all around, checked everything again, hoses, oil, i put my hand on the manifold and it felt fine, and water was coming out the exhaust. so i dont know what the problem is and thats why i posted. sorry for the long post but i think every detail is closer to figuring out whats wrong. thanks

Are you sure that there is nothing wrong with the gauge. If you say the engine is cold, or at least not scalding hot, then you might have something wrong with the gauge. The electrical connection may be loose or bad... There may be something wrong with the wire. I would begin by testing the back of the gauge with a volt meter. Check to see if the voltage is changing a lot causing the gauge to read the different readings. Next, check to see if the sensor that is giving the voltage to the sensor is OK. I am sure that there will be some more people to post that may have a better idea.

Elo,
Excessive smoking??? Could be a head gasket. Did you take notice if there were any traces of water in the oil?

What color is the smoke?

Over-rich mixtures burn black.

A motor with bad valve guides and/or rings gives off blue.

White is indicative of water loose in the system.

This could point you in the right direction.

You could pull the spark plugs when the motor is cold and see if they are wet. Leak down or compression test would be a good idea.

I thought of compression test but it runs strong and i think it almost runs better then before, (besides the smoke) as for the gauge, i thought that it might have a bad connection, when i use the horn the temp lowers about 5 degress, so thats whats probally up with that. The oil is good, i made sure there was no trace of oil and the smoke is white. so what else should i check? thanks

If the temperature gauge changes when you use the horn (how often do you use the horn????) then I would say that you have a problem in the electrical system. It sounds to me like the voltage getting up to the main panel is bad, probably a bad connection or corroded contact somewhere. What does your volt meter read while this is going on? I will further guess that it is the ground, not the positive, that is having trouble.

White, I would lean towards a head or a gasket. I dont know but you should get it checked out before you put anymore hours on it.

It may be minor but it is surely something that needs to be tended to.

just keep using the horn

head gasket, no doubts....did you get it hot? If so you might have fried the heads! Either way they have to come off. What happens is the water seeps into through the heads and causes steam then escapes through your exhaust. Hope it's just the gasket because if you got her hot this could be expensive and timely.

Yeah a cracked head(which I doubt you have) is extremely expensive. With your temp gauge acting up, it may not be working at all. That could lead to a minor case of overheating which is not good.