Water pressure problems revisited.. More info...

[Vinnie]

Well, the saga continues..

For the record, I bought a 225 ProMax powerhead attached to a 260 mid section from a board member. I was assured it ran great when it was taken off the boat a few years ago. I later found the powerhead gasket was shot along with the lower crankshaft seal....

I then bought a resealed Sportmaster from another member/dealer on this forum which included a new water pump. We checked it, it is he right one and it "appears" to be new and is installed correctly. The water pump is one part I havent replaced..

Water pressure was all over the place. I have since replaced the gauge (no difference), the water presure line(no difference), the thermostats (no difference. I bought a rebuild kit and CAREFULLY rebuilt the Poppit valve (no difference). I have tried the 260/280 water restrictors. (I was also told I could not run these in a ProMax because the engine would run lean and dump fuel because it would not get up to temp).

The "best" water pressure was with the .090 restictors. Even with these, water preassure DROPS when you start to go above 5000 rpm and accelerate.

It goes up to about 15 lbs to about 3000 rpm. It will fluctuate from about 12 lbs down to 7 lbs as I push it. I then back out to protect the motor.

One shop told me there are water pressure issues when you put a ProMax powerhead on a 260 mid. Something about the holes in the 260 mid being the wrong size for a ProMax. Another told me this was not true.. (go figure)

If this thing ran "great" before it was stored, what could be the issue? Any ideas would be greatly appreciated. Yes the motor is deep in the water. I'm not running it too high..

This has become a real pita.. Driving me nuts....

Help..

Thanks

[transomstand]

You've made a number of changes in the powerhead without affecting the pressure. I would borrow a another lower as a test, if still no change, you've eliminated any problem there.

There can be problems using a Promax on a 260 mid (different adapter), but if you have the motor I think it is, I think it's got the correct adapter (2 piece), and it did run well.

Pete

[Vinnie]

Yes, it is the motor you think it is. Yes, it has a 2 piece adapter. With all due respect, I have doubts this motor was ever running "right". I am 140 miles from the closest Sportmaster I know of..

The tach is also acting up once in a while .. Rectifier problem also??

[John Richied]

:smiletest:For the tachometer unplug the tach lead from the rectifier it’s currently plugged into and plug it into the other rectifier.


I don’t mean to question you but are you certain that it’s a two piece adapter plate, because if you were running a ProMax on a 1” plate that is exactly what would happen, water pressure all over the place for readings.

Also is the poppet installed and does the hose run off it to the top of the block or out the back and dump?

[transomstand]

I have doubts this motor was ever running "right"

Here's a really lousy photo of it never running "right" at the Conn. River Run in 2003, it ran like this all day long. Same in 2004, 2005.

http://i221.photobucket.com/albums/dd58/transomstand/Artcopy.jpg

[Jay Smith]

I have the "best" luck running the Pro Max motors I build ( Stock AND modified ) with the stock 2 piece tuner adapter with stock poppet valve and stock clean thermoststs..

These Pro Max engines cooling systems run flawlessly when their not altered...

just my .02

[Vinnie]

All the defenders of the seller are showing up. No offense but that does me little good. Please let me correct my wording, It may have run well back then.

Jay,

As I said in the first post, new thermostats, (part # 75692) and a "fresh" poppit valve. I used the Mercury rebuild kit for it (rebuild kit # B03062T 1). The spring was stiffer than the one I replaced. Water preasure did improve slightly. The thermostats that were in the motor were "mismatched" as in 2 different ones. The new ones are correct.

John,

Questioning me is no problem! :) I am not an "expert" in any way. I have been told it is a 2 piece adapter. The top motor mount is in a separate 3" plate. I replaced the 2 leaking gaskets on top of the plate between the midsection, cowl and powerhead. There is a gasket under the adapter plate. The poppit valve hose goes to the top of the powerhead.

Only thing I have not changed is the new water pump. As I said in the first post, the gearcase was purchased from a dealer that posts on this board. He resealed it and installed a new water pump. We checked it and it looks to be correct.

I guess next step is a new water pump unless you guys have another idea.. I appreciate the technical asistance very much. Already July and I have not "opened it up" yet!

[transomstand]

All the defenders of the seller are showing up. No offense but that does me little good. Please let me correct my wording, It may have run well back then.



What will do you some good is fixing the problem in the lower unit, then it may run well once again. I wish you luck, and hope you find it soon.

[Vinnie]

What will do you some good is fixing the problem in the lower unit, then it may run well once again. I wish you luck, and hope you find it soon.

Ok, What can be the problem with the lower unit? Again, we took the waterpump apart and it looked good. All was new.

What are your suggestions?

[pickwickangler]

Make sure impeller will not spin around if the drive shaft is held in place. Take the big plug out of the top of the sportmaster and make sure they aint some debris in there, check the water tube for cracks, check where the water tube connects to the water pump has a rubber washer in it to help seal off, check the same thing where it goes into exhaust plate.

[us1]

Can you post a picture of the adapter plate sounds like its a one piece plate.

[transomstand]

Make sure impeller will not spin around if the drive shaft is held in place. Take the big plug out of the top of the sportmaster and make sure they aint some debris in there, check the water tube for cracks, check where the water tube connects to the water pump has a rubber washer in it to help seal off, check the same thing where it goes into exhaust plate.

Pretty good advice there, I would also confirm the water tube, pump cover, and exhaust plate are all correct size.



Can you post a picture of the adapter plate sounds like its a one piece plate.

Here's a photo

http://i221.photobucket.com/albums/dd58/transomstand/artmid2.jpg

[Jay Smith]

The picture shows it to be a two piece adapter and IMO you'll be fine. I had a poppet kick my keester a year or so back causing pressure to bounce around and never level out, I found the male donut thats pressed into the female of the block was loose and as the pressure built the donut moved as the springed plunger did. The way to "fix" it was to take the poppet out and with a small punch BRAD the boss the rubber donut is fitting in , in other words punch a small tab of metal 3 to 4 places over the donut preventing it from moving did the trick for me..

Good luck,
Jay

[us1]

Its a two piece. It should not be dropping pressure at higher speed. If you are sure its not getting air in the water pickups at high speed get back into the poppet.

[Vinnie]

I will be taking the gearcase off again on 7/17. I will double check everything again. I will also take the poppit valve apart and check it over again. I will use a differnt poppit valve and transfer the rebuild kit over to it.

Guys, Thanks again for the imput. s I stated before, this is driving me up the wall.

I will post after I double/triple check everything again..

[transomstand]

I read this post again, and I'm a little concerned about that poppet part number you posted. It doesn't appear to be a Merc part number, and I've not seen Merc sell a kit in the past, always individual components.

[Vinnie]

I read this post again, and I'm a little concerned about that poppet part number you posted. It doesn't appear to be a Merc part number, and I've not seen Merc sell a kit in the past, always individual components.


Sorry Dude, It is a Merc kit. I opened the bag myself. I don't post photos but I saved the Mercury plastic packaging bags on everything.

[transomstand]

Ok, it's the 18th, what did you find? Enquiring minds need to know:D

[Vinnie]

Ok, it's the 18th, what did you find? Enquiring minds need to know:D

I was unable to work on the motor yesterday. My buddies that help me were away fishing. Now I have to wait till the end of next week.

Yes, I am going to drag the boat about 140 miles to my buddies house now and take it apart.

You seem very interested.. Maybe you can make the trip to Norwich NY and take it apart for me. 5 years ago , I could do it myself. Not any more....:thumbsup:

[platypus]

Just double check that waterpump base gasket (lowest one) i have change my water pump kit twice this year come to find out it was the lower base gasket ( torn )


Art

[Vinnie]

OK, lower unit off again. Everything looks fine still... Here is something very interesting though.. First and for the record, my hearing sucks....

I had a buddy in the boat and he heard the motor making a noise which went up and down and fluctuated the SAME as the water pressure. After a minute, I heard it also.

At a steady 4000 rpm I could hear it easy after a while. You could watch the water pressure go up and down with the same "cadance" as the motor...

Rpms did not fluctuate..

OK....... Help!!

[Vinnie]

UPDATE!!!!!

Replaced the waterpump this weekend and swapped the poppet valve with another one. Here is the status.....

As rpms go up, pressure goes down. I took off the water pressure line at the motor. I lowered the gearcase all the way in the water at least 8" past the gearcase. As I raised rpms, the water from the fitting would increase then all of the sudden, it would start to act like it was sucking air.. Took it out for a short ride, pressure dropped from 15 to 7 once rpms went up.....

It ain't the poppit valve, nore the water pump.....

We are leaning towards the gaskets on the adapter plate OR the adaptor plate it self.

Any ther suggestions??