1980 260 Mercruiser question

[ctparks]

I want to first say that I'm new to the boat owners world and also want to apologize if I ask something that has been covered somewhere else in this great and very informative forum.

I recently purchased a 1980 Century Cortez230 with a 260 Mercruiser engine. I took the boat out to the lake for the first time last weekend. The launch went well and it cranked right up. I creep out of the docks and then bump up the throttle to about half and then to 3/4 and was cruising along nicely. I went to wide open and you could hear the 4 barrel open up and then it sputtered a bit and then died with alot of associated steam coming from the blower vents. It would not crank back up immediately and stay running; after waiting approx. 15-20 mins it cranked back up to idle, however when I put the engine cover back on it died again with steam again. After getting it started again, I left the cover off and limped it back to the ramp where it ran the whole time, however i never tried to go above 1/4 throttle again after that. After i shut down at the ramp, again alot of steam came out of the engine compartment.

Could it be that the motor was either flooded when I went to WOT or not getting enough fuel? Also, does the water get pumped in from the stern drive via the water pump or is there another pump that needs to prime the cooling system with water after you're in the water? I had two switches that I was unfamiliar with...one was the blower switch-which I'm glad I found out what that one was for before I got out and the other is a water pressure switch. In some forums I was reading I was under the assumption this switch was for water pressure for the fresh water tank for the sink, toilet, etc. Again, I apologize if I sound ignorant or asked some stupid questions, but like I said I'm new so please go easy on me. Any help you can provide is greatly appreciated.

 

[Howard Sterndrive]

Re: 1980 260 Mercruiser question

alot of associated steam

steam generally indicates overheating. What was the temp gage reading during this?

How are the exhaust manifolds and risers?
Has a mechanic looked at the boat recently?

does the water get pumped in from the stern drive via the water pump .

yes.. the water pump is in the lower unit of your outdrive and that rubber impeller inside it would be my first suspect

water pressure switch.

That's unrelated - probably for the sink

 

[Bondo]

Re: 1980 260 Mercruiser question

After i shut down at the ramp, again alot of steam came out of the engine compartment.

Ayuh,... Did you Look to see Why and/ or Where the steam was coming from,..??

 

[ctparks]

Re: 1980 260 Mercruiser question

Thanks for the quick replies. Yes, a mechanic has looked at it the week prior to me taking it out and said everything was good. I found the source of the steam...the exhaust manifold hose blew open I couldnt seen where it was coming from the night I was out as it was pitch dark by the time I made it back to the ramp. Would it most likely be the water pump in the stern drive or on the engine? How hard is it to replace the rubber impeller inside the water pump? Should I replace both water pumps and a thermostat as well? Thanks again for all your help.

 

[chiefalen]

Re: 1980 260 Mercruiser question

Did you notice the temp gauge and what it did ?? Won't hurt to put a new t-stat in.

If you want to know how to do a water impeller in the drive go to the top of the forum and click on " Adults only " and click on the manuals and pull the one you need and d/l it. It's free thanks to Don s.

You will need a new hose.

After doing the impeller and t-stat, run it on the water again with a working temp gauge. Watch that gauge if it goes over 180 back off the throttle and if it doest cool quick shut it off and let it cool and limp back in again.

Then it could be alot of other things, you have a heat exchanger, risers clogged, flapper broke off, the last one might have happened already cause of the over heat.

Hows the oil in the motor?

 

[Howard Sterndrive]

Re: 1980 260 Mercruiser question

the exhaust manifold hose blew open

blew open?
or melted?

if blew open - an exhaust shutter most likely fell off and is jammed in the outdrive's exhaust chamber

if melted - raw water pump in outdrive quit pumping

 

[ctparks]

Re: 1980 260 Mercruiser question

Did you notice the temp gauge and what it did ?? Won't hurt to put a new t-stat in.

Yea, the temp guage went to right at 240 and thats when I backed it off. I let it sit for about 30 mins then cranked it and limped back to the ramp with the engine cover open. What degree T-stat needs to be in it? Also, there's 2 hoses that run from the t-stat to both sides of the block and then there's 2 other hoses that are both sides of the t-stat that just loop back around and connect to the other side, like someone had bypassed something at one time. It doesn't look right at all...I will post pics when I get home this evening of what I'm talking about. Do you know the hoses I'm talking about and if this is correct?

Hows the oil in the motor?

The oil looks fine, no evidence of water or looking burnt.

blew open?
or melted?

if blew open - an exhaust shutter most likely fell off and is jammed in the outdrive's exhaust chamber

if melted - raw water pump in outdrive quit pumping

It blew a hole in the side about the size of a quarter. The hoses looked quite old and probably dry rotted. Also, Do you happen to know what size hose I need for my engine? I'm trying to find a replacement for it, but I'm at work at the moment and dont have the specs with me. I'm going to replace both sides while I'm at it cause the other side don't look like its going to last long. Where would I look to see if an exhaust shutter fell off and got jammed in the outdrive exhaust chamber?

 

[Howard Sterndrive]

Re: 1980 260 Mercruiser question

Where would I look to see if an exhaust shutter fell off and got jammed in the outdrive exhaust chamber?

down where the exhaust comes out of the outdrive -
One of the other threads here had this pic of one jammed in...

But while replacing those hoses, you'll be able to do a visual on your shutters. they are right where the hoses go on.

Don't worry about size - order the hose by Merc part number.

 

[ctparks]

Re: 1980 260 Mercruiser question

Ok thanks I will check the exhaust shutter after I go to the boat shop and pick up a couple new hoses and a t-stat. Do you think I may have caused any other damage with it being ran like it did?

 

[mh11]

Re: 1980 260 Mercruiser question

I just bought a 1978 galaxie 22xl with the 260 merc in it a few months back. Same thing happened to me at the lake the third time out. I was by myself, out for an hour or testing a new prop, and smoke starts coming out from my leg by the throttle control........needless to say, I look at the dock about a mile away, and I am thinking I am burning the boat to the water, good oil pressure, temp round 180, but smoke coming when full throttle, none when back off.........

You should need the 3"-4" inch rubber bellows if I remember correctly, mine didn't blow, but split about an inch long crack which is where the steam was coming from..

You said temp hit 240????? That is not right, post that pic that you have.

Think this is the merc number you need. 70981A3

 

[ctparks]

Re: 1980 260 Mercruiser question

Thanks mh11 for the info, however the part# you listed is for the exhaust bellows and that is not what blew on me. i have a 3" marine exhaust hose that comes off the back of the exhaust manifold elbow thats about a foot long that goes straight back to an exhaust elbow down to the exhaust bellows on both sides. After going to the marine shop the parts guy said that my motor has been modified and that is not how he shows my motor to be routed. After researching in the service manual it appears that I have 260R exhaust manifolds and a 260 t-stat housing so the hoses I mentioned earlier that comes out of the t-stat housing and loops back around back into the housing is supposed to go the front and back of a 260 exhaust manifold. On the 260R it just has a T fitting where the hoses just route to the front of the exhaust manifold elbow and goes overboard where mine has a plug installed in it. Could I take the hose with water flowing out to the elbow and cap off the other port on the t-stat housing thats not used on the 260R. Thanks again for all replies and info provided.

 

[Bondo]

Re: 1980 260 Mercruiser question

After researching in the service manual it appears that I have 260R exhaust manifolds and a 260 t-stat housing so the hoses I mentioned earlier that comes out of the t-stat housing and loops back around back into the housing is supposed to go the front and back of a 260 exhaust manifold. On the 260R it just has a T fitting where the hoses just route to the front of the exhaust manifold elbow and goes overboard where mine has a plug installed in it. Could I take the hose with water flowing out to the elbow and cap off the other port on the t-stat housing thats not used on the 260R. Thanks again for all replies and info provided.

Ayuh,... Got Pictures of what you've got going on,..??

 

[ctparks]

Re: 1980 260 Mercruiser question

Ayuh,... Got Pictures of what you've got going on,..??

I've got pics, but I'm currently at work and the pics want upload. I will post pics this evening.