OMC Overheating issue 120hp help

[2fast4u_evinrude]

Hey there I have a sea ray 16 ft boat with inboard 4 cylinder OMC engine inboard. I belive its a 1.8L 120hp from 1979. Took it to the water and noticed the temperature was goin passed the middle and then to the "hot" temp. Started to smell and smoke so I shut it off. Jump into the water and see that there was like lots and lots of sea weed caught on it. got it all removed and cruised my way back to the dock. Temp was fine on the way back to the dock reving about 2500rpm. Cruised for about 10 min and then the temp shot up again. So I shut it off didnt bother driving it anymore. I got someone to tow me back to shore. When we unloaded the boat there was like tons of seaweed caught on the propeller. Im talking its wraped in there where there is lots of restritions on the propeller when you spin it. I took it home and ran a garden hose through it and it ran fine no overheating. Would the seaweed be the reason for the over heating? Since I overheated it twice is there something I should check to make sure every thing is ok? Head gasket etc? THanks

 

[Howard Sterndrive]

Re: OMC Overheating issue 120hp help

120HP is a 2.5L

sounds like both overheats were from weeds blocking the water intake screen

I wouldn't worry about the head gasket too much, but compression test the engine to check it

If the boat is new to you, you want to change the impeller in the outdrive a.s.a.p., mainly so you can grease the water pump shaft splines

the impeller is less than $20- so not worth taking chances on

shifting to neutral. then to reverse and giving a quick throttle usually clears millfoil weeds, but where are you boating?
Even Scugog isn't that bad...

 

[2fast4u_evinrude]

Re: OMC Overheating issue 120hp help

120HP is a 2.5L

sounds like both overheats were from weeds blocking the water intake screen

I wouldn't worry about the head gasket too much, but compression test the engine to check it

If the boat is new to you, you want to change the impeller in the outdrive a.s.a.p., mainly so you can grease the water pump shaft splines

the impeller is less than $20- so not worth taking chances on

shifting to neutral. then to reverse and giving a quick throttle usually clears millfoil weeds, but where are you boating?
Even Scugog isn't that bad...

Thanks for the info. I assuming that the engine starts no prob means that my motor is ok. I dont know much about boats. I am not sure what part # for the impeller and where to locate parts for this boat. If I post some pics would that help? I want to take this on another run but afraid it will smoke and overheat again. Should I look at thermo stats or water pump? It was at mission lake in saskatchewan. Seaweed galore. Went int this tight spot to cross over to another lake and there was lots of seaweeds too. Parts of the lake was like 3 feet deep and u can see lots of sea weed.

 

[Howard Sterndrive]

Re: OMC Overheating issue 120hp help

the first part you need is a service manual. You can buy the original manual on eBay or new from Ken Cook publications.

You can buy the impeller at ANY place selling boat parts, and most NAPA auto parts stores if the guys at the counter have half a clue. You can order it from iboats.

If you want original quality- go to an Evinrude dealer, or shop.evinrude.com (you can look at parts breakdowns there, but they do not ship to Canada)
Impeller is rubber and needs to be replaced every few seasons, and especially after the torture it just endured.

 

[2fast4u_evinrude]

Re: OMC Overheating issue 120hp help

Ok ill go check out the parts at a local dealer today. Someone told me becuase I overheated the motor I might want to change the valve cover gasket becuase I would of melted/dired it out

 

[Howard Sterndrive]

Re: OMC Overheating issue 120hp help

you don't need a valve cover gasket, but that is MY OPINION, of course

this is a modern dilemma... "so and so told me this", "and I read that on "chevytechdudes.com", and I read another thing in a forum

Can you give me a 12th opinion???

it seems quite common with old OMC powered boats, because they are cheap or free, and no one wants to spend more on the manual than the boat, but unless you want to turn what you have into a pile of scrap, go read a manual

that's the only advice that you should take with 100% credibility

The factory manual was produced by the guys who designed and made your drive system and they really had a vested interest in seeing it survive at the time of publication

the manual doesn't tell you everything and that's where iboats kicks butt. Guys here can put the technical terms into perspective.

 

[2fast4u_evinrude]

Re: OMC Overheating issue 120hp help

so would this be the service manual I need?

http://cgi.ebay.ca/OMC-stern-drive-...Motors_Manuals_Literature&hash=item3f01aba8b0

 

[Howard Sterndrive]

Re: OMC Overheating issue 120hp help

so would this be the service manual I need?

http://cgi.ebay.ca/OMC-stern-drive-...Motors_Manuals_Literature&hash=item3f01aba8b0

that's a stolen copy of an aftermarket manual that someone is selling

if you are going to steal it- don't pay him for it - visit the adults only thread at this site and oddly, most public libraries have it

I recommend the factory manual. You need to find out the year and model of your rig to get the right one.
The Seloc manual (stolen one floating around) will help you identify your proper year and model, and it is "ok" for water pump impeller instructions

this sort of thing, but for your year and model
http://cgi.ebay.ca/1971-OMC-Stern-D...Motors_Manuals_Literature&hash=item1c0a6ace95

 

[2fast4u_evinrude]

Re: OMC Overheating issue 120hp help

Do you know where I can find out what year the boat will be? I think the name of the boat is either sunray or searay. Model is SV 156. Trailer is registered as 1978 so im guessing somewhere around that year. I did see 1971 with a bunch of writing on the valve cover but that might be the established date of something

 

[Howard Sterndrive]

Re: OMC Overheating issue 120hp help

boats aren't registered or insured in that province?

check for a hull ID number starboard side of hull on transom just below the rub rail - last 2 digits are the year

a pic of the drive would help (i.e. read the Seloc manual) as 1977 and 1978 are 2 quite different drive systems

oh, and read the manual

 

[2fast4u_evinrude]

Re: OMC Overheating issue 120hp help

There is a number on my boat, I just have to go home and check it later. Ill also post some pics to show what I have. We just register the trailers and not the boats in this province.

 

[2fast4u_evinrude]

Re: OMC Overheating issue 120hp help

here are the pics

 

[Howard Sterndrive]

Re: OMC Overheating issue 120hp help

that is a low profile, electric shift drive
1973-1977 is as close as I can get from the pics

it's not older than 73 (73 first year of low profile)
not newer than 77 (77 was last year of electric shift drives)

an OEM manual for any year 73-77 would work

 

[2fast4u_evinrude]

Re: OMC Overheating issue 120hp help

that is a low profile, electric shift drive
1973-1977 is as close as I can get from the pics

it's not older than 73 (73 first year of low profile)
not newer than 77 (77 was last year of electric shift drives)

an OEM manual for any year 73-77 would work

Theres a number on my boat ending with 74 so that means its a 74. So do you know lots about this motor? Is it solid? Good bad? Anything I should know besides getting the service manual? I mean overheated this this to the red line twice.

 

[Howard Sterndrive]

Re: OMC Overheating issue 120hp help

Is it solid? Good bad? .

compression test it

by design it is reliable, simple and of a family used in millions of boats...still used today by Mercruiser and Volvo penta in it's bored out 3.0L version

 

[2fast4u_evinrude]

Re: OMC Overheating issue 120hp help

Came home and started it today for about 10 min with the garden hose to it. I noticed that the needle on the temp gauge did not move at all. I dont even see the needle at all. Wonder if I burnt out the temp sensor or something? Also How would you check the impeller if its functioning? I went to a local boat shop today and they says that to replace it will be 2 hour @ $95/hour plus part. I would attemp to do it myself but they say that I will most likely mess it up.

 

[Howard Sterndrive]

Re: OMC Overheating issue 120hp help

How would you check the impeller if its functioning?

look at it after you put the new one in just before you throw it away

I went to a local boat shop today and they says that to replace it will be 2 hour @ $95/hour plus part.

that's pretty fair

ask how much extra it will be if you watch

 

[2fast4u_evinrude]

Re: OMC Overheating issue 120hp help

So what would be the chance of me having a destroyed Impeller? I want to take the boat out this weekend, not sure if its worth the risk

 

[KRH1326]

Re: OMC Overheating issue 120hp help

These are the files that I supplied for the Adults only sticky. The links are gone now but the files are still there.

1964-1986 OMC sterndrive manual:

http://www.4shared.com/file/zF-DZrvB/1964_-_1986_OMC_Sterndrive_Man.html

1987-1998 OMC sterndrive manuals:

http://www.4shared.com/file/2Vy3uORd/1986_-_1998_OMC_Sterndrive_Man.html

1964-1998 OMC wiring diagrams:

http://www.4shared.com/file/K3ct2McS/1964_-_1998_OMC_Wiring_Diagram.html


Good Luck

 

[2fast4u_evinrude]

Re: OMC Overheating issue 120hp help

These are the files that I supplied for the Adults only sticky. The links are gone now but the files are still there.

1964-1986 OMC sterndrive manual:

http://www.4shared.com/file/zF-DZrvB/1964_-_1986_OMC_Sterndrive_Man.html

1987-1998 OMC sterndrive manuals:

http://www.4shared.com/file/2Vy3uORd/1986_-_1998_OMC_Sterndrive_Man.html

1964-1998 OMC wiring diagrams:

http://www.4shared.com/file/K3ct2McS/1964_-_1998_OMC_Wiring_Diagram.html


Good Luck

Awsome thanks for the great info