89' SunBird 5.0 OMC I/O overheating issues

[dolphins7272]

Ok, I have done some extensive trouble shooting and still stumped! I believe the problem is that its not getting enough water! I have tested the intake of water flow from the intake hose to the water pump on the motor it self, I believe its not getting enough! There isn't any water until I self Prime the water pump on the lower unit. I can blow thru the primer hose and its not blocked. After self priming the water pump, I started the motor up with the 'muffs' and disconnected the hose to the manafoldes and strangly enough there is water isn't going into it until a gasp of air is released. then flow is weak and spirts "not a clean flow". I just got the boat back from the Marina for repairs. They have replace the impeler and gaskets. I beleive its located in the lower end. I fear they have done an inadiquit job. Please help with any suggestion

 

[Lou C]

Re: 89' SunBird 5.0 OMC I/O overheating issues

Sounds like they did not seal up the impeller housing right, it may be sucking air.<br />It is not a hard job to do yourself if you have an OMC manual.

 

[dolphins7272]

Re: 89' SunBird 5.0 OMC I/O overheating issues

where can I get a OMC manual? or a diagram ?

 

[Lou C]

Re: 89' SunBird 5.0 OMC I/O overheating issues

Check with an Evinrude/Johnson dealer, they can still get OMC Cobra sterndrive parts.<br />You can also get the aftermarket manuals like Seloc and others.<br />for a diagram go to <br />www.dougrussell.com <br />they have all the diagrams and also sell the parts you need.<br />I did mine last spring and if I recall the whole impeller repair kit is pretty cheap, if you are mechanically inclined it takes about an hour to do.<br />The impeller in the Cobra is behind the plastic cover that is at the rear of the upper gear housing.

 

[dolphins7272]

Re: 89' SunBird 5.0 OMC I/O overheating issues

OK, Another issue I think, After dropping the upper gear housing from the Transom mount and making sure all the seals are tight. Making sure there isn't any air leaking from the gasket for the Upper gear housing to the Transom. I also made sure that the O'ring on the sleeve for the impeller to be in good shape. Also The impeller is brand new. I removed the impeller and primed the cavities. I also resealed the impeller housing, making sure now air leaks. Please any advice woould be greatly appriciated. I'm pulling the Lower gear case off tomorrow. Something isn't letting the water get to the impeller to push it into the weater pump on the motor. Maybe another water pump somewhere? Machanicaly inclined , but my first boat!

 

[ZZ3Astro]

Re: 89' SunBird 5.0 OMC I/O overheating issues

I just dealt with a similar problem on my 96 Volvo SX 5.0. In the following diagram, the part marked #18 (raw water hose nipple) was cracked almost all the way around, letting air in.<br /><br />OMC Transom Mount Diagram <br /><br />Of course I guess on the OMC the impeller is on the drive so the nipple would be a positive pressure area... So maybe this won't help at all!<br /><br /><br />Mine works great now after replacing the nipple and all the seals and hose.<br /><br />steve

 

[dolphins7272]

Re: 89' SunBird 5.0 OMC I/O overheating issues

I have inspected this part also when I removed the upper gear housing from the transom. The nipple was in good working order. I even applied air pressure to that point and no leaks. Is there another pump that may be misfunctioning? Or a another point of failure?

 

[Lou C]

Re: 89' SunBird 5.0 OMC I/O overheating issues

There is a water transfer tube in the lower unit that has seals on it that can leak. Go over to <br /><br />www.dougrussell.com and look at their diagrams, but before you start pulling off the lower, get a manual!