1995 4.3GL Liter OMC cobra

[Shade Tree boy]

Hello,

I plan to winterize my boat soon. I have a service manual so I am comfortable about everything except the drain plugs in the engine block. I think mine only has 2. One on each exhaust riser. Does this sound right for my particular engine?? I know that the 4.3 liter mercruisers have 4 plugs and so I am concerned that maybe there are additional drain plugs that I am unaware of. All tips for winterizing this type of engine are much appreciated.

 

[a70eliminator]

Re: 1995 4.3GL Liter OMC cobra

you 4.3 has 4 drain petcocks, one on each manifold and one on each side cylinder engine block, you'll want to diconnect the big hose from your waterpump, and the long smaller hose at the t-stat and lay it down low to drain, this should also take of your p/s oil cooler if it's mounted right. Also when draining petcocks make sure they aren't plugged with rust and sediment, you can just unscrew them all the way out and shove a piece of wire up through to make sure it's clear of debri.

 

[Shade Tree boy]

Re: 1995 4.3GL Liter OMC cobra

Thank you Captain Eliminator! I assume all these plugs will be accessable at the rear of the engine. Is this correct? Are there any other concerns about freezing with these engines that I should know about?

 

[a70eliminator]

Re: 1995 4.3GL Liter OMC cobra

There's one right next to the starter on the starboard side, the port side is just to the rear of the oil filter, the manifold drains are at the bottom of the manifolds, access to the drains depends on how much room you get once with engine cover off, some boats are easy, some are more challenging.

 

[Shade Tree boy]

Re: 1995 4.3GL Liter OMC cobra

Captain Eliminator... I haven't found 4 petcocks. I have, however, found two petcocks. One on the port and one on the starboard cylinder block. The exhaust manifolds have what I would call caps at the rear. They are nothing more than a rubber cap attached to the rear of the manifold with a hose clamp. Are these the manifold drains you speak of??? The petcocks look completely different. They appear to be brass and they stick out of the block walls about 2 inches.

 

[Don S]

Re: 1995 4.3GL Liter OMC cobra

The rubber caps are how you drain the manifolds. Use a wire to clean them out, rust and dirt tends to plug up the holes.
The petcocks may even be plugs, remove them completely so you can clean the holes to make sure the block is drained and not plugged up. (both sides)
Remove the hose on the engines circulation pump and drain. Drain the power steering pump cooler if you power steering.