OMC Cobra

[aydemir]

Good evening,<br />I've just a bought a used boat with an OMC Cobra (Ford 2.3). I am quite new to boating (first boat) and also nervous about taking the boat in the water without testing the engine first. Is there a way to test this engine on my drive way? Is there a coolant port for this engine that I can attach a garden hose for example? At the water pump inlet? I don't want to do something wrong and ruin the engine, any help will be much appreciated.<br /><br />N. Aydemir

 

[Lou C]

Re: OMC Cobra

You can run it on the hose in the driveway at home, you need to get a good set of "earmuffs", these slip over the intake ports on the outdrive, get the good kind with the hose inlet at the end of a tube that goes into both of the muffs instead of just one as on cheaper muffs. Hook up your hose to the muffs, (MAKE SURE NO ONE AT HOME IS USING THE WATER IN THE HOUSE OR YOU CAN OVERHEAT THE MOTOR!!!), make sure the drive is as far down as you can get it (remove prop to be on the safe side) and you are ready to run it. I run the blower before starting just as you would in the water. First turn on the water, then crank the motor to start. After it starts, reduce idle speed a bit, get off the boat and make sure the muffs are still on, and make sure there are no kinks in the hose. Water should be exiting from the drive (look up under the transom mount, near the bellows). Carefully watch the temp gauge to make sure it does not overheat. Most engines will not overheat at idle speeds, but if you run it faster than that the hose may not be able to supply enough water and it could overheat. Normal temp on an OMC with a 160 thermostat is about 160-175 or so. When shutting off, first turn off the motor, then turn off the hose.

 

[aydemir]

Re: OMC Cobra

Thanks. So I understand that outdrive is where I'll be attaching the "ear muffs". just curious...where is the recirculating water going to be coming out of? Outdrive as well? There must be a different exit for the (now hot) water. I've just ordered a shop manual so hopefully I won't be asking these ignorent questions once I read up on this engine.<br /><br />Thanks again,<br />N. Aydemir

 

[Lou C]

Re: OMC Cobra

For one thing get an OE OMC manual, you can still get them from dealers that sell Johnson/Evinrudes.. the oe manual is far better than aftermarket.<br />The water exit on the Cobra with the OE sealed exhaust bellows is from holes in the lower unit of the outdrive (little holes that are near the aft end of the lower unit) and the prop itself at higher speeds. Many cobras have an after market exhaust bellows that is slit on the bottom to let the exhaust out faster, mine has this and that is where most of the water comes out.<br />Like I said you have to be careful doing this, it is a good idea to remove the prop just in case, and make sure no one in the house uses the water, and also check to make sure that the muffs have not slipped off and the hose is not kinked. Don't forget that the hose can only supply enough water to run at idle (600-700rpms) not at higher speeds. To see the bellows I am talking about you need to tilt the outdrive all the way up and look between the drive and the mount on the transom. But do not run the engine with it up like that, it will be hard on the ujoints, always try to keep it as low down as you can .

 

[aydemir]

Re: OMC Cobra

Lou C,<br />Thank you very much for informative explanations, much appreciated.<br /><br />N. Aydemir

 

[Lou C]

Re: OMC Cobra

My pleasure, you will see if you get the OMC manual the way the cooling system works is nicely laid out and it will be easy to understand with the diagrams provided.<br />I learned all this in the last 8 months or so, never worked on a marine engine before but have had lots of experience with cars, that's why I like inboards and stern drives.