Engine Temp.

[Cricket Too]

Just looking for a quick verification on the general rule of thumb of what temp most OMC's should be running. I know the general shade tree rule is, that you should be able to keep your hand/fingers on the engine for about 2 or 3 seconds, before having to take them off. Wondering if that is correct or not.<br /><br />Have my 115 back to the shop I bought it off of, because in my opinion it runs cold, since I can leave my hand on it all day and it barely gets warm. The t-stats are one of the things I specifically asked the shop about when I bought it since it's a bubbleback, and I wanted them done before I bought it, as not to have to deal with it myself until I need to. They told me they were done and good. I don't want to run into a cold sieze situation, so I took it back. Was told by one of the mechanics at the shop that you "should" be able to keep your hand on it all day, and if you have to take your hand of after a couple of seconds, that it's running too hot. Everything I have ever been told or read here, has said the opposite, so I just wanted to know where I stood, before I go back to talk to the owner of the shop. Thanks.

 

[DHPMARINE]

Re: Engine Temp.

There are wax crayons for measuring your engine temp.The 'orange' one should melt (125 degrees).<br />The 'blue' one should not melt (163 degrees). Around 140 - 145 degrees is a good norm.I can't think of much else that would make it run cold,except thermostats (or lack of them).<br /><br />DHP

 

[OBJ]

Re: Engine Temp.

Hey Cricket.....<br /><br />Trust this.....on the flat area on top of the block just forward of the heads, with the engine at idle and being warmed up, you should be able to lay your fingers on the flat areas for several seconds before you have to move them off. This is about 140 to 143*F. It will get uncomfortable after several seconds. But not to the point it will burn you. At above idle and WOT, it will get up towards 150* area. This is normal.<br /><br />If the "person" at that shop said you should be able to leave your fingers there all day....find another wrench.<br /><br />EDIT: And yes...what DHP said. He just types quickerer than me.....

 

[DHPMARINE]

Re: Engine Temp.

Heck OBJ,I had a 4 minute head start.<br /><br />Cricket Too,tell us what the selling shop says.Also what year is this motor ?<br /><br />DHP

 

[reeldutch]

Re: Engine Temp.

probbebly your tstats are stuck open.<br /><br />there are several posts on tstat replacement.<br /><br />if you go to a dealer and ask him to do the stats,<br />you wil get a bill of about 400 dollars to replace a part of 30 dollars.<br /><br />they will lift your power head to get to the t stats.<br /><br />but if you do it yourself you can do it leaving the ph on.<br />it aint fun but it is possible.<br /><br />and yes if you can hold your hand on it all day something is wrong with the tstat assy.<br /><br />good luck

 

[Cricket Too]

Re: Engine Temp.

Hey guys, thanks for the answers. The engine is a 1976 115, but the powerhead was replaced in 1997 with a PMC powerhead. The guy at the shop who said that is the one who usually works on the Merc's, so I don't know if Merc's run a lot cooler than OMC's, but I doubt it. When he said it I just kind of yessed him and changed the subject. He won't be the one working on the engine anyway, so it didn't really matter to me, just got me thinking. Thanks, I let you know what they say.

 

[Cricket Too]

Re: Engine Temp.

Thanks reel dutch, I figured as much. I just bought the engine a couple of months ago, so they won't charge me to do the stats. I have done them before on a bubbleback, which is why I wanted them done before I bought it, so I won't have to do it again for a little while.

 

[OBJ]

Re: Engine Temp.

Problem with a bubbleback....you either have to pull the powerhead or.....pull the powerhead. The bolts that hold the bottom of the exhaust cover on (bubble back) are just near impossible to get to to remove and losing the lower pan just don't give any more room to work in. So....with a bubbleback, it's really more efficient time wise to pull the power head.

 

[b.gagnon]

Re: Engine Temp.

What does the water output feel like? The air temp may make the engine feel cold....

 

[reeldutch]

Re: Engine Temp.

you dont have to lift the powerhead.<br /><br />those tstats wil need the be servised every 5 years if your lucky.<br />i drilled 3 wholes in the pan to acces the bolts.<br />look:<br /> http://groups.msn.com/outboardpictures/shoebox.msnw?action=ShowPhoto&PhotoID=10 <br /><br />and after your done you fill the wholes whit a metal putty or bondo some spraypaint and you saved yourself 350 dollars.<br /><br />its up to you.

 

[OBJ]

Re: Engine Temp.

Well, that's one way to do it reeldutch. But most engine owners don't want holes drilled in their pans.....but as you said, it's up to the owner.

 

[Solittle]

Re: Engine Temp.

Replacing the thermostats on crossflow bubblebacks can be done without dropping the pan or pulling the powerhead. I have twin 87s & have done it. I have one 7/16" box that fits the two outer bolts. I can turn the bolt just a little bit and then must flip the wrench over. Once the tension is off I have a 1/4" drive socket with a universal and extra long (12") extension that gets the bolts the rest of the way. It ain't fun but can be done.

 

[Cricket Too]

Re: Engine Temp.

Reeldutch..That's actually the way I did it on my old '76 140. Have tried your way too SoLittle, but got frustrated and drilled the holes, never really got them filled in the way I'd like though. Reeldutch what did you use that would stay in the hole? How did you get Bondo to stay in the hole, without popping out? That's where I had the most trouble. <br /><br />Only reason I brought it back to get done was because I just bought it from this shop. If I had bought it from a guy who had it on the side of his house, you can bet I'd be drilling holes in it right now and doing it myself. At least this way I won't have to bother for a few years.

 

[reeldutch]

Re: Engine Temp.

i used a plummers metal putty.<br />you can get it at home depot its in a small tube.<br />sand the inside and outside for better adhesion.<br />let it harden for a day an sand it down.<br />thats what i did.<br /><br />some people glas a strip of fiberglas inside and use bondo on the outside.<br /><br />i dont realy like the messy fiberglas in side the pan.

 

[Walker]

Re: Engine Temp.

If you drill holes then go to an auto supply and look for those plastic plugs the put in car door panels. You know, the kind that sorta snap in. Get the plugs before you drill so you know waht size hole to drill.

 

[Silvertip]

Re: Engine Temp.

And then paint the plugs so they look a little less obvious.

 

[reeldutch]

Re: Engine Temp.

here is a picture with the plummers putty<br /><br /> http://groups.msn.com/outboardpictures/shoebox.msnw?action=ShowPhoto&PhotoID=22 <br /><br />thats totaly waterproof and doesnt look to bad i think.<br /><br />good luck

 

[dsujen]

Re: Engine Temp.

I have a 1986 110hp evinrude. Trying to do the thermostats. I'm going to cut a rectangular piece out of the lower pan and then mig weld it back. I've tried to lower the pan, but it didn't help. I had no problem getting all of the bolts out and the thermostat hosing and spacer out because there was nothing inside. When I tried to re install with the guts inside I realized it would be impossible. I don't want to remove the powerhead because i feel like i'm going to open up a can of worms. Plus I would have to make something to lift the motor off with my chain hoist. It's easier just to cut and patch I think. I can't believe this motor was designed this way.

 

[DHPMARINE]

Re: Engine Temp.

sujend14,<br /><br />If you assemble all the parts together (thermostat body,valve body,therms,relief valves) using type 'M' sealer,and let it set up in a vice or even bolted together,you can then install as an assembly.The springs are a bit hard to deal with,but it's do-able.And beats a square hole in the belly pan.<br /><br />DHP

 

[Cricket Too]

Re: Engine Temp.

Hey Guys, so just an update on my '76 115. I got a call from the shop late last week. And the guy is trying to tell me that the t-stats are fine. I told him I thought it was running too cold since at idle I can hold my fingers on there all day. I told him that I didn't use any wax sticks on it, but that it's nowhere near the 140+ that it's supposed to be if I can hold my fingers on the heads. <br /><br />He told me that he can tell it's opening by looking at the lower unit. Not sure what he means, but I guess there is something that opens with the t-stat and flows water through the lower unit, and he can see water coming out of it, so he's telling me the t-stat is opening, but to me that just proves that the t-stat is open, and my whole point is that it's stuck open and running cold, so that seems like a BS answer to me. Then he told me that older models used to run cooler than the newer ones and that the fingers on the head rule only applies to newer motors. Again I believe this to be BS, as I have a '75 70hp Johnson, that at idle, no matter what time of year, I can only hold my fingers in for 2 or 3 seconds. He's trying to tell me that the engine only uses the t-stat at idle anyway, and that whenever your off idle the t-stat is wide open and doing nothing, but I am almost boggled by this answer, because it seems to me that the t-stat is there to regulates temp and pressure, and even if it was wide open, it would still create some resistance to keep the engine at a certain temp. <br /><br />Am I correct here? Because my next step is to go directly to the owner and start raising my voice, my patience is wearing thin, and the last thing I'm gonna do is get taken for a ride. So I really need to know if I have a leg to stand on here. Has anybody ever heard of older engines running cold, being normal??? I seriously suspect this guy of being too lazy to do the right thing. I really need to know if this engine is supposed to be running around 140 degrees, if so I want to see him hold his hand on 140 and hold it there all day. I know a lot of you guys out there are professionals, so that's why I ask, so that I know for sure if I go in there with this argument, that it's solid and not just hearsay. Thanks a lot, Mike.