200 Mariner

[Blue_Heron]

All the above is good advice. I would add just one thing. If you're going to work on your Mariner yourself, buy the FACTORY service manual, not a Seloc or other after market manual. The factory service manual will give you step by step instructions for changing the water pump, cleaning the carbs, pulling the power head, and everything in between. You can usually pick them up on ebay for about 20 bucks.
Dave

[jobu]

Sorry for taking so long to respond but it's been non-stop rain here and the boat has been on the back burner for a while. That said, I changed the thermostats and was still getting similar results. But when I run it with the thermostats out it really flows good (and I have hardly no water pressure at my house)
The poppit valve...is this also called a diaphram?
I bought one from the local Merc dealer and he gave me a schimatic...looks like the lower right bank of block. But there is also an electrical panel there...stupid question but does this have to come off first...and also is this the poppit valve?
Also, thanks to everyone who has responded...I haven't been on in a while and forgot how helpful everyone here is!
Thanks,
Joe

[jobu]

Okay...here's the status.
New stats...same thing...low to no pressure out of top tell tale at idle.
New poppet valve....same thing(there was some seaweed...also I put the round plastic disc that goes between the valve and screw convex side pointing in?).
Drop the LU redo the impeller, gaskets, housing exactly...put key back in...line up LU and reinstall with minimum difficulty...Now I get NO water out of all three...I assume that I didn't line up the water pipe correctly...I try it again and get no water still. Is there a trick to lining up the guide for the copper pipe? Does the pipe attach first to the upper part or to the pump housing first...also if anyone can explain the order this would be great. Also I cant see it but it looked like I got it lined up right so maybe something completely different. If anyone can help it would be greatly appreciated.
Thanks Joe

[Bigshrimpin]

Joe there should have been a little plastic tube guide included with that kit. It helps line up the top of the water pump . . . so that the copper tube can slide into the correct place and seat into the rubber grommet. You need two people to do this job or a ratcheting tie down to hold the lower into place.

[jobu]

So the rubber grommit goes in the housing then the plastic guide goes into that(tightly) and when you slide in the unit the copper pipe(already attached to the upper drive housing)slides into the plastic guide pipe and eventually into the rubber grommit and housing?
Thants how i thought it worked...but must not have gone right...is that right? also I did get a new white pipe but didn't see new rubber grommit?
thanx Bigshrimpin...Im still up
joe

[nos3665]

I have seen Great instructions here, Just a question tho, as you bolted the water pump housing to the LU did you rotate the shaft so the impeller is free?

[Blue_Heron]

...Now I get NO water out of all three...I assume that I didn't line up the water pipe correctly...I try it again and get no water still. Is there a trick to lining up the guide for the copper pipe? Does the pipe attach first to the upper part or to the pump housing first...also if anyone can explain the order this would be great. Also I cant see it but it looked like I got it lined up right so maybe something completely different. If anyone can help it would be greatly appreciated.
Thanks Joe

A few thoughts:

The new water pump housing probably already has the rubber bushing installed, so all you need to do is place the alignment tube and the pipe will seat properly.

Also, did you turn the drive shaft clockwise (looking down from the top) when you seated the impeller in the housing? If you turned counter clockwise, it may not pump.

And did you remember to place the key on the flat spot in the driveshaft before dropping the impeller down the shaft? Without the key, the impeller ain't going to turn.

And I reiterate my recommendation to pick up a Merc shop manual. All things are clear when you've got the book.

Good Luck,
Dave

[jobu]

After the third try,I eventually got everything right with the key and the pipe inlet. Also the impeller was in right and shaft turned clockwise. Now I'm getting water...not steady though. Screw it, it's sunny I'm going in. I dropped her in Plymouth harbor and ran it around at idlw to 1000rpm and it seemed fine. As soon as I got into the channel and got up to about 3000rpm...beeeeeep! the alarm went off.
I later pulled and dropped her off at the boat yard. The mechanic said it looked like the pipe was not seated correctly at the top end . They had it running in a barrel and seemed to be pumping better but still intermittant at idle but pretty steady at 2000-2500. With my hand on the head at 2500 it was actually cool...but when we idled it for a while it got up to 135'F then it looked like the thermos would open and would drop to 119'F.
Not totally convinced but she's going in as soon as it stops raining. Maybe tomorrow or Thurday.
Fingers are crossed and a report will follow.
Any more ideas welcome....the only thing I can think is that there is something floating around in one of the lines???
Thanks for the all support,
Joe

[Bigshrimpin]

It sounds like it's running perfectly. Those blackmax motors run hot compared to others and what you describe is "normal" based upon my experience with them. I love those motors.

[Blue197320]

I love those motors.

and it shows.
i need a collection of motor parts like that.