165HP IL6 Mercruiser overheating???

[Skipster1]

What might be the basic causes of my 165hp InLine6 I/O suddenly overheating?<br />It has never overheated before, has just been tuned up and running real good.<br />I had her tied up to the dock and was warming up the engine when she just kept getting hotter - over 180. The outdrive was totally immersed in the water.<br />I'm hoping it's basic and would appreciate some starting points to look at.

 

[Bondo]

Re: 165HP IL6 Mercruiser overheating???

Pull the "Incoming" hose off the T-stat housing,+ Crank it Up........ You Should have a Good Solid Flow from the outdrive.......<br />Next is the T-stat.....<br />Then the Riser........

 

[Skipster1]

Re: 165HP IL6 Mercruiser overheating???

Sorry Bondo, I wouldn't know which hose that is nor where it's located?<br />And when do I hook that hose back up???

 

[FreeBeeTony]

Re: 165HP IL6 Mercruiser overheating???

The hose bondo is refering to is coming from the gimbal housing inside the boat and going to the thermostat housing. It probably runs inbetween the valve cover and the carb. Disconnect it from the thermo housing before starting the engine, you could put the hose into a bucket if you want. You should have a good stream of water as soon as the engine starts. You don't have to run it long. If the water is there, shut it off and take the thermostat housing off to inspect the thermostat.

 

[Skipster1]

Re: 165HP IL6 Mercruiser overheating???

Okay, thanks. The question still stands... when do I hook the hose back up????<br />And what might be causing the overheating?

 

[tommays]

Re: 165HP IL6 Mercruiser overheating???

I think they said if water is flowing shut it off 20 seconds should be plenty of time<br /><br />i thing you would find a servic manual very helpfull it will show all the parts and tell how to test each one at 35 dollars its one of the cheapest tools you can own<br /><br />quite honestly allmost anything in the cooling system from the water pump inpeller at the begining to a cloged exaust ellbow at the end could make the motor overheat<br /><br />the only way for you or a pro to fix it is to check each part of the system in logical steps until the item that is not working is found <br /><br />it takes time to gain the no how to save money <br /><br /><br />tommays

 

[Don S]

Re: 165HP IL6 Mercruiser overheating???

Bondo is right, in the first reply you received. Some things to think about. The impeller in the outdrive should be replace every 2 to 3 years at least. They are rubber and develop a set and are a maintenance item. Thermostats on closed cooling systems don't go bad very often. Risers and manifolds last 5 to 8 years and on some occasions even more before they get clogged and need replace. Since the 165 haven't been used for a while now, I would suspect if nothing has been done in a few year, it's time to start looking at everything. If you just got the boat, a manual is now a manditory tool for your tool box.

 

[Bondo]

Re: 165HP IL6 Mercruiser overheating???

I wouldn't know which hose that is nor where it's located?

In that case,<br />Bring it to a Marina.....................<br /><br />If you have No Clue as to What is Where ........<br />There's Really Nothing any of Us can do or say to Help you...................<br /><br />At this point,<br /> You've either got to Learn What's, Where........(Manual ?????)<br />Or,<br />Bring it to Someone who Does Know..........

 

[Skipster1]

Re: 165HP IL6 Mercruiser overheating???

Bondo... I know enough to know that you're right.<br />However, I have a serious family problem that needs taking care of and I have this boat up for sale on eBay (19' Galaxy fishing boat) so I simply don't have the time needed to spend on fixing the boat.<br />All I know is that she was running perfect after a good mechanic tuned it up and checked her out.<br />Now, all of a sudden, the OD won't rise and she overheats.<br />May be wishful thinking but I figure this is something simple but I don't know enough about this system to know where to look. Assuming I am right - that there is something simple causing these two problems - what might it be???<br />Thanks,<br />Skip

 

[Bondo]

Re: 165HP IL6 Mercruiser overheating???

Skiph,<br />I'm truly sorry to hear of your misfortune.......<br /><br />I can't think of a Single thing that would cause Both of your problems........<br />Seeing that Your time is limited,+ The boat is For Sale.......<br />I would think that a call to the good mechanic is in order.......<br />After all, He's the 1 who just finished your Tune-up..... If the issues are Related to His work, I'm sure he'll be accommodating.... <br />If Not, You still get the boat Fixed,+ will be able to sell it as a Running Boat........<br />My 1st reply to your thread is the sequence to diagnose the Cooling Issue..........<br />For the Trim, Start with Power to the Pump Circuit...... And Go from There.........<br /><br />Good Luck, with both the Family,+ the boat......