merc 200 20hp water pump

[furrjt]

help. i have gotten the engine to start but i'm <br />not sure about the water pump. i have the engine<br />foot in a drum of water. when the motor is running shouldn't there be water coming out somewhere? if the pump is bad how do you replace it? thanks for any help you can give.<br /><br /> jeff

 

[Motor Boater Bill]

Re: merc 200 20hp water pump

Yes, it must pump water, but before you tear it down find the "pee hole" and run a wire or piece of string trimmer string up there and make sure it isn't plugged up. Bugs live these holes and I have had to clear mine more than once.<br /><br />If you don't know when the water pump impeller was last replaced, you should do it. A manual is a good investment as you will save more on repairs than the manual will cost. The factory manual is best.<br /><br />Parts and manuals available at www.oldmercs.com<br /><br />What is the serial number on your motor?

 

[furrjt]

Re: merc 200 20hp water pump

s/n is 1294739<br />is the water pump impeller hard to replace if<br />it is the problem? thanks for your help.

 

[Motor Boater Bill]

Re: merc 200 20hp water pump

The impeller is not that hard to do, but you should get a manual, especially if you are new to outboards. Might try your local library if you don't want to buy one. <br /><br />But if the pee hole is plugged, a new impellor won't make it pee. Find and clear the hole first, then you can see if it pees. Once you know it is moving water, you can check other systems, see what other parts you need, and order them all at once--or at least that is what I'd do. Also change the lower unit oil and see if it is milky or looks like the color of peanut butter, or has water in it. This will tell you if you need to replace the lower unit seals. You will want to do that while you have the lower unit off.<br /><br />Impeller is about $15. If there is no water at all coming out, it may be the impeller or it may be that someone dropped the lower unit and didn't get the water tube aligned when they put it back together. But I'm betting on bugs in the pee hole.

 

[Motor Boater Bill]

Re: merc 200 20hp water pump

WHOOPS!! Sorry, just checked your serial number, this is the "automatice transmission" model, and the water pump is notoriously difficult to replace--so definitely see if you can clear the pee hole and hope that's the problem!

 

[Chinewalker]

Re: merc 200 20hp water pump

Also, make sure the leg is buried DEEP in the water, as the auto-tranny motors have the pump up higher in the leg than a standard shift unit. They sometimes need a little help getting primed to start pumping. <br /><br />Regardless of whether you get the motor pumping as it is now, it is HIGHLY recommended that you see about replacing the impeller. If it is old, it WILL fail, and usually when you can least afford it to, .ie when that big cruiser is bearing down on you and the idiot behind the wheel is more interested in the babes in bikinis on his rear deck than he is the poor sap dead in the wate ahead of him....<br /><br />Manuals and parts available from Grubbs at oldmercs.com. Doesn't hurt to poke around your local area and see if you can ferret out a semi-retired mechanic who knows the older Mercs, too...<br /><br />- Scott

 

[Motor Boater Bill]

Re: merc 200 20hp water pump

I'm sure Chinewalker can help with the specifics on this, but I think if the powerhead is good it can be tranplanted onto a different leg and lower unit in the event the auto tranny lower becomes a deal-breaker for you in terms of working on it. Scott?

 

[Chinewalker]

Re: merc 200 20hp water pump

Hi Bill,<br /> Parts and pieces, maybe, but there are differences in linkages, etc. that make a straight transplant complicated.<br /><br /> If Jeff wants to take the time to cobble together a few tools and make it work, the auto transmission motors work quite well. Really a neat system - just a bugger to service if it needs it... and why they put that pump where it is we'll likely never know...<br />- Scott

 

[Motor Boater Bill]

Re: merc 200 20hp water pump

Please, Scott, don't do this to me, you're going to make me end up buying one of these myself off of eBay, I mean, they often go pretty cheap, and I kind of like cobbling special tools together...must...resist...don't bid...ahhhhh!

 

[furrjt]

Re: merc 200 20hp water pump

thanks for the info<br />where is this impeller and how can i get to it.