Merc 4.3L MPI Overheated on Driveway

[Sirovc2]

2015 Four Winn's 180 with Merc 4.3L MPI. I was doing oil change, put on rabbit ears, started her up to warm the oil. It ran for probably 7ish mins and the overheating alarm went off. I quickly turned it off and went and did my oil change.

But now I'm worried. Did I do any damage? Is there a different issue I need to address? I've been reading up wondering if I need to change my impeller? It's never been done. I'm a DIY guy as best I can be but really nervous to try and tackle an impeller change.

Maybe I take her out on the water and see how it all goes. Boat/engine has been flawless since day 1.

Thoughts?

 

[alldodge]

I've been reading up wondering if I need to change my impeller? It's never been done

Yes impeller needs to be changed

Maybe I take her out on the water and see how it all goes.

:nono: don't do that before impeller has been changed

Its not that hard, and not doing this one, kind of tells me there might be other things that need to be looked at

Is this a Alpha or Bravo drive?

 

[Sirovc2]

Yes impeller needs to be changed



:nono: don't do that before impeller has been changed

Its not that hard, and not doing this one, kind of tells me there might be other things that need to be looked at

Is this a Alpha or Bravo drive?

It is Alpha One drive

 

[Rick Stephens]

Did you look to see if water was flowing out of the gimbal housing after a couple minutes? That's the all important question whenever you start up on muffs. Go back and look. Within a couple minutes water should start coming out the pressure relief ports in the gimbal housing.

Annual maintenance requires removing the drive, inspecting and greasing u-joints and gimbal bearing, inspection condition of bellows and then changing oil in the drive. It is not that much further to split the cases on Alpha drives and changing the impeller. A couple hour job that save you a lot on labor and time at a mechanic.

 

[Sirovc2]

What kit do I use for this drive?

 

[alldodge]

The impeller kit is 47-43026Q06

Complete rebuild kit is 817275Q05

 

[Sirovc2]

Wish me luck!!!

 

[alldodge]

That's just the impeller, do you have the gaskets?

 

[Sirovc2]

That's just the impeller, do you have the gaskets?

This is what is in the package. I think this is everything?

 

[alldodge]

Cool :thumb:

So long as the pump housing is not damaged you should be good to go

 

[achris]

This is what is in the package. I think this is everything?

'Tis...

You'll need some gear oil too. Merc recommend only using their High Performance Gear Lube. And for reasons I have witnessed, so do I...

Chris....

 

[Sirovc2]

Got the impeller swapped out, new gasket etc. I can't get the damn drive back on. Does the boat need to be in forward gear at the throttle? I read two different things, leave it in neutral or can be in forward drive. I left it in neutral... Think I messed that up. Can I put the throttle in forward drive and try to put it on again?

 

[achris]

Did you remove the whole drive, or just the lower half? If lower half, any gear is ok as long as you line up the lower and upper shift shafts. Whole drive, it MUST be in forward to both remove and refit.

Chris.....

 

[Sirovc2]

Did you remove the whole drive, or just the lower half? If lower half, any gear is ok as long as you line up the lower and upper shift shafts. Whole drive, it MUST be in forward to both remove and refit.

Chris.....

Just the lower half. Pics below. I searched the forum and found a few threads on others with similar challenges. Spent two hours last night trying to get it back on. Going to try again today.

 

[alldodge]

It is a bugger getting it back together the way your doing it. I've done it but last time a friend called me over to help and I said nope, not this time. He didn't have a new gasket so we went and got one. Pulled drive, turned upside down, then slid the bottom onto the top. Took 30 seconds and were bolting it together

As Chris said, move throttle into forward gear before remove or install

 

[Rick Stephens]

I'm with AD. No way I'm lifting the lower up to reinstall.

And wow - been like forever since I had a pretty new looking outdrive like that!

 

[Sirovc2]

Got it on! That's wasn't fun.
What should I look out for when I take her out for any errors in my re-install? Biggest one I've read is it stays in neutral?

PS- Thanks for all the help. Couldn't have done this without you guys

 

[alldodge]

You should be good if you fired it up and have water coming out the exhaust and not pouring out between the halves

 

[Sirovc2]

You should be good if you fired it up and have water coming out the exhaust and not pouring out between the halves

Too scared to fire it up on the driveway now ... I'll take her to the lake down the road and test it out I guess.

 

[havoc_squad]

I'm with AD. No way I'm lifting the lower up to reinstall.

I thought I was weakling wimp back about 4 years for struggling to get my Gen 2 lower on from an impeller change.

If I had issues with spline alignment, I just put it back on my DIY stand and used the prop while the lower was in forward gear to make small adjustments.

The first bolt/nut is the hardest so that the weight is supported. After that, it's all gravy.

Sirvoc2, did you check verify the old lube did not have water intrusion?

Did you verify that the lube hole o-ring between the upper and lower was properly in place and not damaged or warped? That is a part included when you get the impeller assembly kit, not just the impeller.

With the drive as level/down as possible, did you fill high performance gear lube from the bottom hole until it comes out of the top vent hole, close the vent hole, then unscrew the lube reservoir monitor and keep filling until it reaches the fill line?

Did you do a basic water pump check with muffs on a hose that supplies sufficient water pressure? You should at least be able to reach and maintain safe operating temperature on the engine and manifolds and hold that for 700 rpm idle.

Any further tests would need to be made on the water under load or with a dyno that supplies high enough water flow/pressure.