OK so the over heating continues OMC

[Alexo1us]

Re: OK so the over heating continues OMC

Thanx for the input.<br /> I'm not sure if it was freezing that caused the cracks in the manifold I assumed it was, you know how Cast is it could be just as easy been the Overheat caused them. The plug just came out sort of popped out after I had repaired the lower unit, which was leaking at the side covers and the water started to get in the block before the thermostat opened. Is there away to tell about cracks. I.e. if I ran clear hoses would this indicate air or something.<br /> I did a compression check last year all were in the 125-130 range I would think a blown Head gasket would show here. Also would there not be some indication of water in the oil. In mine even though she indicates overheat the oil is still the same color as it was when it went in and no water in it.<br /><br />I think she will be a very good boat when I get this problem sorted out and I will eventually if the RPM is suppose to run in the 4200-4600 range then I’m not far off next prop I get will be lower pitch but this shouldn’t be a problem since I’m not far off the mark.<br /><br />I will keep trying to track it down with help from here. If nothing else I can still use her although not fast she still can get around and if I must pull the engine in the fall and have it checked and re sealed I will leave this to then since. I really do not have the cash for this at this time. But it may come down to it. I just can’t get over the symptom of the thing stopping the Over heat when lifted slightly. This just doesn’t make any sense. Unless there is some sort of blockage in the lower unit. I really do not want to try it my self. Ball gears are just about shot now. And I was going to replace them over winter since I will need to have the lower unit off to fix all the stripped bolts holes ruined by the ***** who has been working on it before.<br /><br />Thanx again Alex

 

[Boatist]

Re: OK so the over heating continues OMC

Alex<br />On my 3.0 when I put a hose on the output of the thermostat it looked like a garden hose with 25 psi and engine cooled down very fast. If you do this also tilt your motor a little and see if it affects the flow. You could still have a problem in the pivot pin area.<br /><br />One thing you could do before you go to the water is hook a garden hose up to the manifold where the thermostat output goes and turn the water on. See if it runs out the prop at a high rate, if not tilt your motor and see what happends. You do not need the motor tunning to do this test.

 

[Alexo1us]

Re: OK so the over heating continues OMC

I haven't had her out yet but a problem I found caused by my desire of not putting too much stressed on the weaker bolts and stuff I managed to put too much of the silicone on and found the thermostat to be partially blocked. And me shooting my mouth of about the others who have worked on it. Boy do I feel dumb now. And I did the same in the pivot area as well so I just may pull these as well but I may wait till I see what happens with the thermostat out besides I will grab a hose and hook it up and see if it cools down fast then I know it still in the exhaust side. <br />No sense in disturbing them unless I need to and I do know that when I did the work in that area it increased the pressure enough to start blowing out loose hoses and that one freeze plug. <br />The guy that gave her to me said that I have come along way he said that last year it would over heat just above idle and there would be no way he have even got her on plan with tilting the drive. So at least I can say I have done something. <br />He always had to take the breather off to open the butterfly just to get her started. I have her running well she starts first time every time with just 1 pump to set it and will idle even if I do not increase the throttle. First time he saw this I thought he was going to fall over. He says except for the overheating she runs better then his new one. And he is sure I get this fixed as well.<br /><br />Thanx for the test I will try this out to how much of the water run out the back from the hose.<br /><br />On another note what is the issue with a name change I can't make out what is was I know she is just a small boat but I was thinking about calling her Second Chance.<br />For many reasons but most importantly if I had not accepted her she would have most likely sat and rotted. And is a lot better name then my wife has been using Hopeit just doesn’t do it for me.<br />Alex

 

[Alexo1us]

Re: OK so the over heating continues OMC

Update:<br />Didn't get time to get her out today weather not good. But I tryed your sugestion of hooking the hose to the to the out side of the manifold with a little twist since I have the thermostat out I hooked to the input of the housing and turned on the hose after short time water comming out the back I would say about the same as going in from the hose. No Problems seen. I hooked up to the input from the intermediate housing to riser. turn the water back on again again flowing out back. this time though I notice water leaking from the hole in the from manifold cover water leaking though to the exhaust chamber of the manifold. discovered the end plate bolts loose and when I got it off I could see on the gasket where it was seaping past.<br />But is starting to look like I could need a new manifold.<br /><br />I also thought I could use the gaskets here with out sealer but before installing them back I used sealer since a closer inspection of the plate showed some imperfections in the sealing areas. bottom line is if the exhaust fills up again I will know there is a crack in the input side of the manifold since the end cap will be sealed. but if the test holds then I going to run the water back out the riser hose though the outdrive see what happens. I guess with the engine running the exhaust was going in the water and since there was no pressure when off the water wouldn't flow back. will be back tomorow after I let the sealer setup over night.<br /><br />Thanx Again Alex

 

[steve n carol]

Re: OK so the over heating continues OMC

alex, have you thought about a cooling hose de-laminating on the inside? <br />also you can pressure test your exhaust manifolds and risers.

 

[Alexo1us]

Re: OK so the over heating continues OMC

Ok so after several more hours of testing I have discovered that the input flow of the water gallery in the manifold has the leak into the exhaust good thing it didn't leak into the exhaust while running could have been bad getting water into the engine. As luck would have it, it didn't so now I'm going on a manifold hunt but in the mean time. I'm going to try and by pass this area looking in the manifold is more for water passage. The area internally that it flows though only covers less then the bottom inside corner of the manifold the riser needs covers more. Bottom line is I know I have to replace manifold I just want to see if I can use it in the meantime. I will keep a close eye on the riser and manifold. <br /><br />Most likely I’ll have to wait until I come up with one but it is worth a shot <br />Alex

 

[Alexo1us]

Re: OK so the over heating continues OMC

Hey for those followed this process <br />Got the Overheating fixed. <br />Well sort of waiting to source a new manifold but with the hose bypassed to thermostat housing she runs at just a shade over 160 WOT. I was concerned about the heat in the riser but it didn't get hotter then the rest of it so I really do not think it is a big issue and will replace the manifold as soom as I can find one the only steam came out of the nipples for the input side of the manifold until the water was gone, But you can tell there is a crack in there I will need to ether vent it out or plug them since I do not want exhaust in the cover. During this time I'll stick in close, just in case. But for now I feel it will run ok for now.I won't run her hard I do not mind crusin at 1/2 very nice ride.<br />Now I have time to fix the other stuff like tilt and trim motors lights on the boat and trailer.<br />and restitch some zippers on the top. <br />Thanx again for all the help I'm sure I will be here again for questions<br /><br />Alex

 

[Alexo1us]

Re: OK so the over heating continues OMC

While never thought I would be back for this post <br />But here it is all went well or so I thought, never got her out but a few times due to time. But dam if she starts it all over again.<br />This time I get pissed and start pulling the engine apart, head gasket blown. Between 2-3 and into some of the water passages. Figured OK another problem found hope it is the last one get her out and she has never ran better at less then 2250 RPM we went out and finished the day crusin around she never skipped a beat.<br />But before I take her out this time I go to home Depot and get 10' of clear hose 5/8 run 1 from the water inlet to the top tube of the thermostat housing by passing the water inlet side of the manifold since it is cracked 1 from the return to the exhaust side of the manifold.<br />Looked pretty cool too I can keep an eye on the flow in real time. All went well at about 2000 rpm the flow starts to build bubbles in the inlet side direct from out drive. Until the flow stops altogether above 2250 drop the revs down to 2000 and the flows starts again. Dam I say to my self it is in the out drive If I hadn't seen where the flow stopped I would have pull the engine I was so sure. But it sure explains why it would cool when slightly tilted up Not recommended btw it really screws up the ball gears.<br />Anyway here is what was done <br /><br />Took off the lower unit to service the swivel housing. There is a lip the runs around the outside on the bottom of housing where it slips into the lower unit casing. Someone before while trying to do something that required removal of the swivel housing broke the lower unit casing, small piece can be fixed with liquid metal of some sort.<br /> Looks like what was happing was the water pump most likely pulled the old silicone though the hole that was left at higher revs in turn allowed the exhaust to flow into the hole as well or it was the exhaust pressure it self ether case the hole was uncovered at higher revs the cavity that the exhaust was getting into was right at the water inlet on the sides (where the muffs sit) Now I not 100% sure this will solve the issue but I’m almost certain enough to replace the thermostat well ok only if time allows before I test it hopefully tomorrow night. Should have seen this before but who ever did this wanted to make sure to cover his tracks he even painted the sillycone after the fact.<br /><br />Will let you know what happens Although In hind site I should mabey wait until I do a test to see don’t want to jinks it.<br />Oh heck Knock on wood!!<br />Alex

 

[cobra 3.0]

Re: OK so the over heating continues OMC

If it still doesn't cure your problem you may wish to buy yourself a mechanical heat guage that you can get for a car. I bought one at Walmart for around $11.00 Can.. I removed the temp sensor and installed this unit instead. Guess what? I never had a heat problem! It was my darn guage playing tricks on me!<br /><br />I had replaced all kinds of parts and spent many hours trying to figure out what was wrong.<br /><br />I took off my manifold that had a long thin crack slightly dripping and running along the belly of the manifold. I grinded the crack open with a Dremel and patched it with metal epoxy (which is holding up nicely), changed the temp. sensor, thermostat, the water impeller kit with casing, undid and flushed every hose, and took off the riser to check if it was clogged...<br /><br />..all that time it was the darn guage!<br /><br />I'm glad I went through the whole process, because I bought this boat last year and didn't know any of its history (It's a 1986).<br /><br />Finally, I have peace of mind. Don't give up!

 

[Alexo1us]

Re: OK so the over heating continues OMC

Thanx for the thought but did that one out first.<br />Didn’t get to even fix it yet. But got all the supplies to do it. Going to try for tomorrow again. For the fixing but should let it sit for a night before I put it into service. I like this cold weld stuff it working on my manifold too but I got a crack on the inside of the inlet side to exhaust so I had to bypass it seems to work all right. No matter which brand of out drive is used the older they get the harder it will be to find parts. And I find that more of these parts are interchangeable then you would think..<br />Anyway this problem just makes sense the more I look at the manual and read about over heating. My out drive pump is working just fine until the flow stops. When running other wise the pressure in the hose is enough that you can't squeeze the hoses. And as long as the flow it there it always runs below 100 since for now I have the thermostat out. <br />But this one is a keeper she runs very nice for the short time I have been able to get her up and moving but it is a very nice cruise at all speeds, like you I do not know the history of mine other then to say she wasn't repaired well in the past. I not saying I don't make mistakes but at least I'm paying for mine instead of someone else’s Hell at least I'm having all the fun!!! <br /><br />I learned not to believe all I have read about OMC being junk they are not.. The only thing I can say is they are little fussier to mistakes then the others they just require more attention to details.<br />Thanx for the encouragement <br />Alex

 

[Alexo1us]

Re: OK so the over heating continues OMC

I got her together during the cleanup of the parts I also discovered that the F##*ing nutbar that did the repair work put washer on the upper seal housing in the lower gear case which intern left a gap at the front of the housing big leak.<br />anyway I used some JB weld to build up the gap held great wasn't a big gap anyway. replaced the washers adjust the repair for fit and gasket maker. Waited over night for the sealer to harden. Got her out this morning and no more over heat the temp gauge didn't move I know I got to put the thermostat back. ran for 2 hrs on plane full flow up the tube. and she ran great..... <br />Now I need to get some the other stuff done like find out why no lights and give her a good cleaning.<br />Thanx for the help <br />alex <br />Got to go Wife now wants a ride.

 

[marinemech]

Re: OK so the over heating continues OMC

hi one thing often f**ked up with these units is the plates on the pivot pin being installed upside down this will give a high rpm over heat problem on any stringer drives <br />just a thought and good luck

 

[Alexo1us]

Re: OK so the over heating continues OMC

Originally posted by marinemech:<br /> hi one thing often f**ked up with these units is the plates on the pivot pin being installed upside down this will give a high rpm over heat problem on any stringer drives <br />just a thought and good luck

Yep I found this two the whole thing had something that needed fixing. On the secound trip She ran just as well as she did this morning.