A little frightened to drop the lower unit on my 85HP Force

[fishthebay]

I have an 85HP FORCE 1987 model. I feel its time to replace the waterpump. I had this done a few years ago at a shop for about $250.00.<br /><br />I am pretty mechanically inclined, but don't want to mess anything up, as the motor runs great and is pumping good water.<br /><br />From what I have read its bascially 6 bolts and the shift linkage held by the cotter pin, which I can see.<br /><br />My first question is is this lower unit HEAVY?<br /><br />Do put some blocks under the lower unit, unbolt the bolts and then take the pin out and then move the blocks and let it drop slowly?<br /><br />Is that all there is to it???<br /><br />After I get it out will I see the waterpump housing?<br /><br />Is it just a matter of taking apart the housing and putting in a new impleller?<br /><br />I have a manual, but its not as specific as I would like.<br /><br />Can I do this myself or should I take it to a shop.<br /><br />The mobil mechanic said he would charge $100 and come to my house. He said the job was 2 hours and I should buy a complte waterpump with new housing and thermostat.<br /><br />Thanks everyone...

 

[scubaman67]

Re: A little frightened to drop the lower unit on my 85HP Force

Just replaced my waterpump on a force 125. Yes it is heavy, but I was able to handle it with one hand as I loosened the final bolt with the other. Water pump housing should be right in front of you as soon as you drop the lower unit. pretty easy to access. My lower unit actually has seven bolts. one hidden under the exhaust plate. be careful of the shift linkage. bending it will cause you a major headache.

 

[jrbpit1]

Re: A little frightened to drop the lower unit on my 85HP Force

My neigbor and I replaced the water pump in my '84 75hp Chrylser, which I think is very similar to your Force. 6 bolts, an allen head bolt behind the exhaust port, and the shift linkage is all that holds it on. My neighbor is a master mechanic so that helps, but it was not as bad as I thought it was going to be. Make sure you have some emery cloth and a little grease to help slide the impeller in. Oh and a rubber mallet to knock the lower unit loose if needed. Good luck.

 

[suzukidave]

Re: A little frightened to drop the lower unit on my 85HP Force

It ain't that bad a job fishthebay and you'll feel like a real mechanic when you're done . Watch for a hidden bolt underneath (usually near the adjustable trim tab but I don't know your motor). You may have to tilt the leg up after you drop it to slide the drive shaft out so it's best to have a second set of hands around. You can just lay the leg down on a piece of cardboard to work on it. Remember to turn the flywheel or prop to get the drive shaft to slot back in after and don't force the gear linkage. Also don't grease the very top of the drive shaft, just the splines.

 

[blew bayou]

Re: A little frightened to drop the lower unit on my 85HP Force

I have a Force 125Hp I just replaced an impeller in two weekends ago. It cost me 2 hours and $14. Taking the foot off is the easy part. Remove the cotter pin on the shift linkage, remove the 6 bolts, and there are two more bolts under the second exhaust tab(the aft bolt is an allen head). Installed impeller in water pump with grease and lined up splines for the next hour. The foot is heavy but, I did it myself with the S.S. prop still installed.

 

[fishthebay]

Re: A little frightened to drop the lower unit on my 85HP Force

Thanks for all the great suggestions.<br /><br />Do you guys recommend changing the waterpump housing or just the impleller?<br /><br />Also, what do you lube the impeller with when installing?<br /><br />Is it hard putting the lower unit back up in? Someone suggested turning the flywheel or prop. Do I do this before trying to slide the unit back up?<br /><br />Thanks again everyone.

 

[Spidybot]

Re: A little frightened to drop the lower unit on my 85HP Force

Consider the extra cost and the work - I'm sure you'll replace the complete thing if there's just the slightest trace of wear in the housing.<br /><br />You can lube it with whatever you want (just not water-resistant grease). This impeller runs in seawater all the time and whatever you decide to put in will be blown out right away upon first start. If you need some lube to slide it in place, use standard/dishwash/household soap.

 

[Bear]

Re: A little frightened to drop the lower unit on my 85HP Force

Take a look at it here:<br /> http://www.mercruiserparts.com/select_docs3a.asp?doc_nbr=FOB4100++ <br /><br />Maybe it is the same picture as in your manual?<br /><br />Good luck!

 

[tjthorson]

Re: A little frightened to drop the lower unit on my 85HP Force

If you use soap for assembly, be sure to run water through it after, so it doesn't dry and get sticky. I did my 125 by myself, its not that heavy.<br /><br />One thing I wanted to add - my LU drain plug was stripped, so while I had the LU off, I pulled the fill plugs and set it upside down over a drain pan. I put it on a workbench so the shaft didn't hit the ground at all. Just might want to check yours to be sure it can loosen.<br /><br />Only other thing I can add is to be careful which way you spin the motor to get the splines to line up. Always spin it in the direction the motor runs at. If you are not sure, bump the starter before disassembly and make an arrow on the flywheel. You don't want to spin it backwards and bend the impeller the other way.

 

[12Footer]

Re: A little frightened to drop the lower unit on my 85HP Force

These guys are good.I can't add to this, except to sugjest you remove your prop first. This will minimise the chances of whacking it on the ground ,bench or garage floor,and risking a bent propshaft.<br />It can be done with the prop still mounted, but the prop should come off easily..If not, now is the time to find out your prop has frozen to the shaft.<br />Better there, than at sea.

 

[RICKRICK1]

Re: A little frightened to drop the lower unit on my 85HP Force

My .02, I did not see it in here above but my merc manual tells me to turn the drive shaft clockwise while in stalling housing over impellar. Have never worked on a force motor so dont know if this is helpful.