mercruiser 4.3 1989 on a sea ray overheating

[bajamovil]

Hi guys i just bought my first boat and took it to the sea, I did a tune up before, I changed the water pump, spark plugs and engine oil, after a few minutes of running in the water the alarm sounded and noticed that the temp was almost reaching 200 so i turned it off and had to tow it back to land, Im very familiar with auto mechanics but total newbie when it comes to marine stuff, I took the cooling system apart today looking for something wrong in the system, I thought maybe a stuck thermostat or something like that was causing the prob. I was reading in the posts about impellers, does my engine on the outside part have an impeller? or only the water pump?, i noticed 2 bilgie pumps 1 its on the floor below the engine i turn it on and it takes the water of this compartment and there's another one out side the boat close to the outside part of the engine, what it this pump for? its not conected to n e switch it runs 2 cables to the batery compartment with little pliers, all the help will be greatly appreciated, i dorve 2 hours to put it in the water and the 1st experiance was a failure, I have the boat in my shop and puted a big tank and sumerged the peropeller inside the tank how do i test the cooling system with out going to the sea again?

 

[bob58]

Re: mercruiser 4.3 1989 on a sea ray overheating

The best thing you can do is buy a Repair Manual for your Motor/outdrive HERE <br />It will show you how to replace your impeller, plus so much more. They are worth there weight in gold!<br />The impeller should be replaced every couple of seasons.<br />If the boat is started out of the water, you will toast the impeller in seconds!

 

[rodbolt]

Re: mercruiser 4.3 1989 on a sea ray overheating

hello<br /> yep if you started it on the trailer for just a min to see how it ran the impeller is toast as well as the upper and lower housings. buy the upeer and lower pump kit replace it and keep cruising. but you may wish to buy and study the manual. next post someone may ask what the part number is for your manual so they can help<br /> good luck and keep posting

 

[JB]

Re: mercruiser 4.3 1989 on a sea ray overheating

Moving to I/O

 

[crazy charlie]

Re: mercruiser 4.3 1989 on a sea ray overheating

If your outdrive is an Alpha it will be easy to replace the impeller,though you may have to chisel it off depending on how long it was run dry.As others have stated,the manual will make this simple.Charlie

 

[cuzner]

Re: mercruiser 4.3 1989 on a sea ray overheating

I would suggest you invest in a flushing attatchment before you buy anything.It attatches to the water intake at the bottom of your stern drive,you hook a garden hose and run the water before you start the engine.Its not a good idea to NOT rev engine to high when you do this. sounds like your talking about your bilge pump on the bottom of bilge,it has nothing to do with the cooling system,it only drains any water that finds its way into your boat.The other thing you mentioned sounds like the bilge or engine compartment blower,it also has nothing to do with the cooling system it is to pump out any gas fumes that build up in your engine compartment. BEFORE you start your engine,its a good idea to turn it on for a couple of minutes. Gas fumes can explode.Your overheating problem sounds the impeller. Its located near the bottom of your stern drive.I can't help you with that,once you figure out what your problem is there are alot of people who will answer any questions you post. Its amazing how much info you can learn from this forum. I would suggest you get hands on a seloc repair manual .Good luck<br /><br /> Jim