Can't get lower unit loose

[Revtro]

I need to change my impeller on my 2003 Merc 200 EFI.  I loosened all 5 bolts, plus the anode and I can't get the lower unit to separate at all.  It's like it's stuck.  I hasn't moved a millimeter.  I knocked on it with a rubber mallet and tried a little prying with a 2x4.. no luck.  I'm afraid to give it too much pressure.  Any ideas?

[Waterfoul]

Trim the motor up and try to rock it off... you can get better leverage. 

2 nuts on each side.  One front and center.  One more above the prop PLUS the anode.  Are you sure you got the one above the prop...?

[Revtro]

There was one up front, two along the side, two underneath above the prop, and the one for the anode.  That should be it right?

[Waterfoul]

Yup, that's it.  It "should" come off now.  Never had one stick though... at least not like you are describing.  I'd try what I suggested before... leverage.  Avoid trying to pry it off... you'll scratch/ding/make a mess.

[Revtro]

No dice.  It doesn't move at all.  I tried prying with a 2x4, banging on it with a mallet, dropping the motor all the way down onto a 4x4 and bumping it, can't think of what else to do.  I downloaded a manual and verified that there are no other bolts.  I doubt the driveshaft is seized up because it doesn't even crack loose at the seam.  I don't want to pry and I don't want to apply heat.  I sprayed some PB Blaster and tried an hour later... nothing.  Brute Force??

[Waterfoul]

Wow.  That's all I have left to say.  Can't believe it won't come off.

[rkillick]

your gonna go check it in the morning and it will be laying on the ground...I have only pulled one and it was on a 72' johnson 50 hp it came off easy...

[mikballa]

hey tom mike here did you try putting the boat in forward gear sometime this will work is the boat over heating let me know mike.

[Revtro]

your gonna go check it in the morning and it will be laying on the ground...I have only pulled one and it was on a 72' johnson 50 hp it came off easy...

I thought of that...I bolted it back up just in case.   I'm gonna let the PB Blaster work overnight and see if that helps.  In the morning, I plan to go give it another try.  One suggestion I heard is to start the boat up and have the bolts half loosened and shift it back and forth a few times.  I'll try to muscle it off first.  Yeah, Mike it overheated today.  Just for a few seconds.  When I gave it gas, it started pulling water and the temp went down.  Fun times.  :/

I'm open to any other suggestions.  I have heard of people putting heat to the bolts...not sure how I feel about that.

[dartag]

There are some good you tube videos on getting if off.  Also check the thermostats.  There should be one on the top of each bank of cylinders.

[Revtro]

Grr.  Tried YouTube.  Not too many people have it stuck this way.  :/  It's definitely the impeller.  At idle, it isn't spitting water, give it just a little gas and it starts spitting.  What I don't know is if there is a seal where the lower and upper units come together.  Will I do damage if I pry?  I am afraid to apply heat because I don't want to ruin the black finish on the LU.  I tried tapping on the most forward bolt with a hammer but I don't want to ruin that bolt.  Hmm.

[djkimmel]

I've learned the hard way more than once that our 'brute force' methods are often the wrong way to go! I would think there is a seal but others on here will know for sure.

[Cy]

Rev,

Go to the auto parts store and get some PB Blaster.  It is he best penetrating oil in the world.  Spray the seam liberally and wait a half hour.  Then tap it with a dead blow hammer and it is doesn't come off spray it again and wait.  It should do the trick!

http://www.blastercorporation.com/PB_Blaster.html

Cy

[Mini]

There should be no gasket or seal between the LU and the Mid Section (at least I have not seen one). I have a 2001 225EFI and mine came off easy when I first pulled it (a few years back).

Are you the original owner? I would hope the impeller had been changed at least 3 times by now! If you are not the original owner it is possible that the backyard mechanic that owned it before you put somekind of "make a gasket" on there first....

When removing you "should" put it in forward gear. And leave both the LU and the Engine in gear until you remount it.

If you cannot get it to move still you may want to post on BassBoat Central in the Mercury forum. There are a couple of REALLY good master mechanics that frequent there and give out all kinds of advice to the do it yourselfers like us. Sherms Marine moderates the forum and European Marine also give plenty of great advice. I would try searching for an answer first before posting....iBoats would be another source of information.

Good luck! I am going to go over there and look too because I find it hard to believe that you are the only person to ever have this happen to!

[Revtro]

Success.  It took some elbow grease, but it finally came off.  I guess I was just a little worried about breaking something.  The rest of the repair went smoothly.  Thanks all for the suggestions. 

[dartag]

Hope that fixes.it.  I had a thermostat freeze up on mine. It would.overheat at idle when you give it gas there is a bypass so it would cool down. 

[Revtro]

Good advice.  I'll definitely keep an eye on it.  On the plus side, it peed water at idle after I changed it whereas it didn't on the water yesterday.  So hopefully I'm good to go.  I have an outing in the am, so I'll "road test" it in the am.  Or should I say "water test"...

[Revtro]

Did I mention that I love being a part of this online community?  Some good folks here. 

[djkimmel]

Glad you got it taken care of.

I wasn't sure about the gasket or seal. Good to know and also a good idea to think about a previous owner possibly adding their own 'seal' to make things more challenging for those this might apply to.

I may have to replace my impeller one of these days. Not sure I'm brave enough to do it myself.

[motocross269]

I have mine done every other year when I winterize....I run in alot of sand and it chews them up...Guys that run alot of hours should probably do it every year...

I had an impellar go out on me while prefishing for a tournament up north...It cost me two days of fishing to get it fixed...So I just do it now for cheap insurance...