Mercruisier 350 MPI Draining

[Laddies]

I have a Mercrusier 350 MPI V drive to drain and have not been able to find out the number of plugs and location, it's a 2004 single pt drain system, the engine is buried and I belive I have found all the plugs, But wondered if any of you have drained one, no one up here in the sticks has a manual or seen one. Guess I'm the lucky one. Help---Bob

 

[Laddies]

Re: Mercruisier 350 MPI Draining

Come on guys is this the only one in the world, has anyone a manual or drained one---Bob

 

[Don S]

Re: Mercruisier 350 MPI Draining

Is that the air actuated system, or the manual, is it raw or fresh water cooled?<br />With the single point drain system, you only have one place to drain it. That's why they call it "Single Point Drain".

 

[imported_wildcat]

Re: Mercruisier 350 MPI Draining

I have the 305 MPI single point drain system. Just open the valve and let it drain. The check valve will open to drain the power steering cooler.<br /><br />This is always a controversial topic, but I then remove the coolant line from the riser (highest point) and the large hose from thermostat. I fill the riser hose with PG until it appears at thermostat. I then reattach the large thermo hose, plug the riser port, and continue filling removed riser hose until PG comes out transom.<br /><br />I know air doesn't freeze, but I like to keep interior of block less susceptible to corrosion.

 

[tommays]

Re: Mercruisier 350 MPI Draining

do you really trust a single point drain system to not clog up with scale ? at some point<br /><br /><br />tommays

 

[Laddies]

Re: Mercruisier 350 MPI Draining

Thanks guys,<br />Don, it's not air actuated, but I found 4 plugs, 1 on the pump intake, 1 on the pump outlet, 1 on the collector unit and 1 on the thermostat hsg, I think you charge the system with air thru that one?<br /><br />Tommays, I hate anti freeze it will always wind up in the ground water, here in fresh water we don't seem to have the scale problems that comes with salt or brackish water. I always run them and open the drains 1 at a time to flush mud and etc. out been doing it that way for 45 years with a couple exceptions that simply don't drain well.<br /><br />Wildcat, thanks for your responce, thats what makes this a great foram, the sharing of ideas---Bob

 

[Don S]

Re: Mercruisier 350 MPI Draining

If you have an air actualted system, there is a small hand pump on the engine and a valve (like a tire valve) you pump up, plus pins that pop out to show the system is opened. The manual system only has a valve to turn.<br />On that engine, they also have a 7 point drain, not sure if they are all there or not when it's set up as a single point drain system, but you can check.<br /><br />

 

[Laddies]

Re: Mercruisier 350 MPI Draining

Thanks Don and everyone else I finally called Tige the boat builder and talked to a service rep. and he says the the 4 drains I found are all there is on the engine, I would feel better if it were the old system, he says it works great maybe so while it's new, next fall I will try to convice the owner to go back to the old system or go some where else, Thanks again guys---Bob

 

[imported_wildcat]

Re: Mercruisier 350 MPI Draining

tommays,<br />great point about the new merc single point drain system possibly clogging at some location. Merc dealer stated that only time will tell if salt water operation will block lines. Merc states that as long as the water is cooling the block, risers, manifolds, then it will drain because it drains the opposite way.<br /><br />Only time will tell.<br /><br />laddies,<br />merc now offers 7 point drain system (normal system), multi-point (your engine), and the single point (which actually has 2 drain plugs if anything gets blocked).