New used boat getting the water flowing

[thewallflowers]

So I just bought a 79 Seawirl 19 ft with a 305 chevy. i/o omc . I heard it run for a few moments as the guy I got it from had no way to cool it. I took it home. I started it up with the motor flusher attached. I hooked everything up and started it with water pouring out at the point of where the flusher is slipped on. it started and ran good for a few min then it shut down. My guess is because it was not getting water where it needs it. I took off the thermostat housing and the thermostat was not there. Looked like no water in the motor. Also if I loosen the hose that goes to manifolds and no water. I let the water run for several minutes and no water showed up from where I took of the thermostat housing or any of the hoses.
Should water pour out before I start it and should it stream out of there if I start the motor? Just don't want to overheat this beast. Do I need to drop the outdrive to do this? Thanks.

 

[Bondo]

Ayuh,.... Welcome Aboard,... The raw water pump is in the drive, which moves the water into the motor,.......
I'm guessin' yer raw water pump needs fixin',......

 

[kenny nunez]

With the engine off, put the control in forward then see if you can turn the propeller in either direction.

 

[thewallflowers]

So does this all need to be checked with the outdrive fully down or up?

 

[kenny nunez]

It does not matter which position the drive is in. This test will show if the drive has a broken shaft or stripped gears in the drive.

 

[thewallflowers]

It does not matter which position the drive is in. This test will show if the drive has a broken shaft or stripped gears in the drive.

ok. in gear i can not move the prop. I talked to a local mech that works on these old motors, 1979, and he said that it sounds like the impeller is bad.

 

[thewallflowers]

Okay I found a good mechanic that charged me $250 to replace the bad impeller with the new one that I bought. Took him 2 hours and it works great.
He said that because the water at Lake Mead is fairly warm to leave out the thermostat and it will keep the motor cooler with the high heat here. I hope he is right! Thanks all!!

 

[Scott Danforth]

if its a cobra, its a 20 minute job to replace an impeller (and that is getting beer and finding your socket wrench) if its a stringer, 2 hours is quite fast.

the thermostat needs to be in the water to regulate the water flow thru the motor. anyone who thinks removing a thermostat allows it to cool better has no clue how the cooling system of a motor works.

 

[kenny nunez]

Just like SD said you must have a thermostat. Without it you are getting a false reading, the rear of the engine is much warmer than the front and also you will start seeing white froth in the valve covers because the front of the engine is too cold.
The lake here in New Orleans gets up to low 90s by August and it never causes any heating unless there is something wrong with the cooling system.

 

[Bondo]

Ayuh,..... Welcome Aboard,..... As noted above, the T-stat is a necessary part,....

 

[thewallflowers]

the outdrive was an old OMC 800 (1979). I wish the impeller was at the lower spot like a cobra. So everyone thinks i should put the thermostat in. Ok I picked up a 160 thermostat and the parts guy said just drop the unit in and put the rubber o-ring in and bolt it down( new gasket). I did see one guy said to RTV the thermostat and the o-ring in place. is that a good idea?

 

[kenny nunez]

If you can get a tool like a scribe that is bent at a 90* angle scrape out the receiver groove for the “O” ring. That should hold the thermostat in place if you have the correct “O”ring. I do not think silicone will be any help.
OMC stringer water pumps outlast Mercruiser drive pumps, If the job was done right you not have to worry, they usually last for years. If something catastrophic happens to the drive then it will be time to consider later and a more modern platform.

 

[thewallflowers]

Ok so we were able to take the boat to Lake Mead for a test run. I took the thermostat along with all the tools we needed to drop it in. Because the boat had been sitting for at least 3 years we put in 2 cans of seafoam and grabbed 2 extra filters cartridges' and installed a see thru inline filter. had a real hard time starting it (forgot to install the second battery) and upon almost giving up on it the motor finally kicked over. THERE IS NOTHING BETTER THAT HITTING THE WAVES WITH WATER SPLASHING AROUND YOU!
It ran fine. It is so good to be on the water again. The only problem is this --- As we left the dock it had a real hard time keeping it straight. we must have looked like we were drunk. Once we got it up to speed, 30 knots, it handled fine. It does not have a whale tail and we have one we can install. Can this be a problem with either an old boat, no whale tail, sloppy steering or??? Now you cant get on the lake hardly as they closed most of the ramps. so we have time to do more work on it. Any ideas on the steering problem?

 

[southkogs]

"Bow wander" isn't unusual with I/Os. You may have to learn the boat a little more to minimize it. Sometimes trim can help, but with your steering type if it's fine when you throttle up then what's happening at lower speeds is normal.

Learn to work with it, and try not to over correct. That's when you start lookin' like the drunken sailor.

 

[thewallflowers]

Thanks for the info. So then what good is the "whale tail"? i have one that will fit so should I use it, I don't have a trim set up on this old boat so will it help or? Exactly what is it suppose do?

 

[Scott Danforth]

So then what good is the "whale tail"?

Making your boat perform bad and lining the pocket of the guy that sold it.

 

[southkogs]

^^^ LOL

I'm not a fan of the whale tails. Supposedly, they help lift the stern when you're on plane/planing and stabilize the outdrive. But, bow wander (as such) is normal. Learn how it works with your hull and don't overcorrect.