Normal operating temp for OMC???

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milkmade61

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I finally got the boat in the water. It is smooth running, but seems to be running a little hot (190-200 degrees F). Of course the water temp of the river is probably over 100 degrees F. Is this a normal operating temperature. Seems to me it usually runs around 160 degrees F. Do I have a problem? If so, what do you think it could be?

3.0 L 140 HP OMC
 
Don S

Don S

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Re: Normal operating temp for OMC???

160 to 180 is normal, 190 to 200 is way over the limit.
When was the last time the impeller was changed.

Of course the water temp of the river is probably over 100 degrees F
Click to expand...

I find that very hard to believe.
 
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milkmade61

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Re: Normal operating temp for OMC???

I just put a rebuilt outdrive on it in June. I have a call to the seller as to when the impeller was replaced. I put a new tstat (160) on as well.

As far as the water temp, the air temp here has been over 95 for a week. My Dad( a 76 y.o. river rat has a thermometer he keeps on the pier).

milkmade
 
chiefalen

chiefalen

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Re: Normal operating temp for OMC???

May I ask what year is the boat? Good sound advise about the impeller.

If the oudrive were rebuilt than it's a moot question.

Ask him when the risers were changed last, or at least checked as well the manifolds.

Also when was the engine mounted water pump changed or checked last.

Was this boat ever used in saltwater?
 
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milkmade61

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Re: Normal operating temp for OMC???

1986 17 ft Rinker, OMC 3.0 140 HP................never been in Salt water as far as I know(I bought it from my uncle w/50 hours on it).

It has a "new" (rebuilt) out drive(this spring) and a new shortblock 2 years ago. It has always been winterized.

I have owned it since 96. I have not done much(other than stated above) except for oil changes, and occasional tune up, fuel pump,new 160 tstat and winterization.

Every spring it starts right up and runs great. I am worried that the 180-200 F operating temp is too high. Prior to replacing out drive it ran at 160. Last year it quit on me after getting up to temp, I took it to mechanic who tried to check impeller and he said it was too corroded to get into to even look at. He told me to junk it. I found outdrive on craigslist this spring and turns out the seller is a boat mechanic, so I hired him to replace the outdrive.

Since I have a replaced the out drive and short block I would hate to ruin either.

Any advice will be appreciated.

Thanks,
milkmade
 
Don S

Don S

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Re: Normal operating temp for OMC???

Do you have a Cobra or Stringer outdrive?
 
chiefalen

chiefalen

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Re: Normal operating temp for OMC???

Still has the original engine mounted water pump? Could be that.

Still has the original riser? Could be that.

Still has the original manifold? Could be that.
 
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1976 Slickcraft

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Re: Normal operating temp for OMC???

When the rebuilt drive was installed did you grease the zirk fitting for the steering swivel. I heard a long time ago that no grease there causes a leak and not all the water from the raw water pump gets to the engine. I usually grease mine a couple of times a season. Also check the seals under the trunion caps they can leak also.
Don`t know what river in MD you go to, but the Potomac at Dam 4 has been running about 86-88 degrees.
Jesse
 
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milkmade61

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Re: Normal operating temp for OMC???

I will grease the fitting today. Also, I will do a water test to see how much is circulating. I am learning a lot on this forum. Keep up with then ideas~

Thank you
 
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1976 Slickcraft

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Re: Normal operating temp for OMC???

You can take the hose that goes from your intermediate housing to the thermostat housing off at the thermostat housing. Start the engine and see how much water comes out. My stringer pumps more than a garden hose does.
Jesse
 
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milkmade61

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Re: Normal operating temp for OMC???

I did the water test and the thing is pumping water like crazy. What about a IR thermometer on the block to see what the actual temp. is? The guage says 190.............could my guage be bad?
 
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1976 Slickcraft

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Re: Normal operating temp for OMC???

I guess the gauge could be bad. Try a mechanical temp gauge. I doubt the outside temp of the block will be the same as the cooling water inside. I don`t know for shure, never thought about it before.
Could be a small rock or piece of impeller or some other crud holding thermostat partially closed.
Jesse
 
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1976 Slickcraft

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Re: Normal operating temp for OMC???

You are getting good flow in, now you have to be sure you have proper circulation and good flow out.
You said last year it quit on you after getting up to temp. What temp did it get up to?
Jesse
 
chiefalen

chiefalen

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Re: Normal operating temp for OMC???

I have the same setup as you. 86 didn't come with a flapper.

Mine don't have a flapper. However I heard stories that 85 motors and outdrives where used in 86 to get rid of all the stringer stuff when they came out with cobra. Actually was supposed to stop using stringer in 85. But the marinas went ape s---t and they had all this inventory of parts and drives. omc held off till 86, And than put out the cobras.

Anyway you could have had a flapper and it broke lose and clogged ya exhaust pipe after the riser way low.

The flapper is there to prevent water from flowing backwards into the riser when you stop and a wake hits you in the back.

Raise the drive all the way up. Look it that big fat hole in the middle of the intermediate housing. Shine a light in there. See a big rubber flapper like in a toilet holding tank? How about in the back of the drive?
 
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milkmade61

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Re: Normal operating temp for OMC???

1976 Slickcraft said:
You are getting good flow in, now you have to be sure you have proper circulation and good flow out.
You said last year it quit on you after getting up to temp. What temp did it get up to?
Jesse
Click to expand...

Jessie- I think 190 or 200. The boat would also just up and quit and after 10 minutes I could get it started and limp back to the dock. I know I have good water flow in. It is stayng at 189 so far this year(too hot). I suppose that if the impeller went up last year a piece could be stuck somewhere. Remember I did replace the tstat.
milkmade
 
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milkmade61

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Re: Normal operating temp for OMC???

chiefalen said:
I have the same setup as you. 86 didn't come with a flapper.

Anyway you could have had a flapper and it broke lose and clogged ya exhaust pipe after the riser way low.

The flapper is there to prevent water from flowing backwards into the riser when you stop and a wake hits you in the back.

Raise the drive all the way up. Look it that big fat hole in the middle of the intermediate housing. Shine a light in there. See a big rubber flapper like in a toilet holding tank? How about in the back of the drive?
Click to expand...

Ok, I can do that......will have to trailer the boat to do so..........
 
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milkmade61

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