FLUSHING '87 Ev 90HP - sorry, I need to repost because I think we got off course some

[bang4dabuck]

My motor overheats when I use muffs to flush my engine but runs proper when in the water. I have replaced both thermostats. I was led to believe that there is a problem involving the WATER TUBE and/or the Grommet. I really, really, really don't want to deal with the GROMMET unless it is surely the problem. So here are my questions hopefully in the right order

1) Premise is I use my boat in saltwater i.e. it needs a flushing Y or N ? (If NO , I don't know what to say)

2) Flushing with muffs is normal and this motor is normal Y or N ? ( If NO, it would make sense one way but not in any other way)

(RIGHT NOW I AM JUST RUNNING IN A TANK SO NO MUFFS. THE WATER COVERS THE WATER INTAKE HOLES. THE 4 HOLES ON EACH SIDE WITH THE TOP HOLE ABOUT 2" BELOW THE CAVITATION PLATE. DO THOSE HOLES EVER NEED ANY MAINTENENCE BECAUSE OF DEBRIS AND WHAT WOULD YOU USE TO CLEAN AND DO I HAVE TO PULL THE LOWER UNIT OFF ? ANOTHER THING I HAVE HEARD HERE IS TO HAVE THE WATER ABOVE THE CAVITATION PLATE BUT DOES NOT MAKE SENSE IF THE ANSWERS TO BOTH QUESTIONS 1 AND 2 ARE YES MAKE SENSE ?)

3) If the previous statements are both yes then there is a problem. Is there anyway to pin down the problem if both are true? HOT ON MUFFS and NORMAL IN WATER Trying to avoid pulling the power head unless it is absolutely necessary to change the grommet.

4) So after somebody here helps me pinpoint that it is the GROMMET, is there somebody here who could tell me there is some sneaky trick I could pull without yanking the power head ?

5) Am I a jerk for restarting this thread Y or Y ? LOL sorry but that last thread seemed like we were confusing each other.

Again my apologies if I wasted peoples time, especially Joe Sorry man.

 

[F_R]

Re: FLUSHING '87 Ev 90HP - sorry, I need to repost because I think we got off course

I haven't read your other thread, but I'm already confused. First you say that it overheats when running on muffs, they you say you are running it in some sort of a tank.

Well OK, I'll try:

1: It doesn't HAVE to be flushed, but it certainly won't hurt. And probably is beneficial. Let's just say I flush mine.

2: Flushing with muffs is the normal and easy way to do it. Overheating while on them is not normal.

3: As I said, hot on muffs is not normal---if you are using them correctly. Must have adequate water supply to the muffs, proper fit and installation. Run it at idle. Make sure it is peeing. Just a few minutes is enough. You aren't ramming around the Intercoastal, just rinsing it out.

3-1/2: It does not overheat when in the water. There is nothing wrong with your motor and it doesn't need fixing. Unless of course it has an old water pump impeller that should be replaced just because of old age. (Called preventative maintenance).

4: There is nothing wrong with your grommet. Don't go there.

5: You are not a jerk. You had questions, I tried my best to answer them. Any more, come on back.

EDIT: I think the problem is the tank----if that is what you are doing. Not picking up enough water.

 

[bang4dabuck]

Re: FLUSHING '87 Ev 90HP - sorry, I need to repost because I think we got off course

OK thanks F_R

In the past I had problems with running on muffs so I switched to a tank. Maybe with muffs it forces the water in and helps the water pump and in the tank for some reason if I don't get the water up over the CAVITATION PLATE I get problems. I was told that that was necessary that the water needs to be over the cavitation plate I am guessing that the water comes thru the exhaust vents too and helps get more water in the system.

Anyways I will pull the tank and hook up the muffs and I do have great water pressure from my hose. If this doesn't solve it I will replace water pump and try again.

 

[F_R]

Re: FLUSHING '87 Ev 90HP - sorry, I need to repost because I think we got off course

The water pump is well above the cavitation plate, so if the water isn't high enough, the pump has to suck it up there. They are great pumps, but they don't suck well. The pump actually is right above where the gearcase bolts to the midsection.

 

[bang4dabuck]

Re: FLUSHING '87 Ev 90HP - sorry, I need to repost because I think we got off course

So again I don't get how muffs can work unless the idea it is PUSHING the water so fast to make up for the water not being above the cavitation plate.

Is that what the point is because the water intake is well below the water pump so i.e. theoretically muffs won't work unless ...

How about cleaning the screens on the water intake ? Do I need to drop the lower unit to clean properly ?

thanks again

 

[Joe Reeves]

Re: FLUSHING '87 Ev 90HP - sorry, I need to repost because I think we got off course

I saw nothing confusing within your previous post which is entitled "OVERHEATING on MUFFS but not in a tank that covers the vents - '87 Ev 90HP".

You were told exactly what your problem is but obviously you don't want to hear it. It appears that you simply want to continue on, acting as if you're failing to understand, and when a member comes up with the logical cure, you simply branch off with some other unrelated question for some unknown reason instead of accepting the member's answer.

You know from replies on your previous post where the water pickup is, where the water pump is located, and where the water level must be in order for the water pump to be functional.... and now you want to rehash all of it all over again?

You've been on the board since 2009 so I know that you're knowledgeable on the subject.

My last word on the subject.... never again!

 

[bang4dabuck]

Re: FLUSHING '87 Ev 90HP - sorry, I need to repost because I think we got off course

Sorry Joe

I will run on muffs.

If it runs hot on the muffs, I will run in the tank BUT this time I fill with water over the cavitation plate.

I just need to know where to go next if it runs fine in the tank (no overheat) but hot with the muffs ???
To me if it runs proper in a big tank but not with muffs there still is a problem. What the problem is ???
Yeah I don't want to hear the Grommet needs to be changed out if I don't know a 100% that that is the problem. You are definitely right about that. Actually I don't want to hear it at all but I can accept it if it is the definitive answer.

Of course if both methods it runs hot I will change out the water pump and run these tests again.

Thanks Joe . I know you help a lot here and apologize for wasting your time. That is/was not my attention. Typing thoughts is very frustrating !!!

 

[F_R]

Re: FLUSHING '87 Ev 90HP - sorry, I need to repost because I think we got off course

Oh, come on now. Certainly you can understand that the hose pressure forces water up to the pump. I say again, if it runs cool in the water, there is nothing wrong with the motor. End of story.

 

[nwcove]

Re: FLUSHING '87 Ev 90HP - sorry, I need to repost because I think we got off course

Sorry Joe, just don't get.
if there is a diff between muffs (over water in take vents) and a tank where those vents are covered with water. Those vents are under the water pump. OK so lets say there is.

Either I run with a very strong water pressure on muffs or if I choose to run in tank I need to go well over the Cavitation plate so there is water sitting in the water pump ?

I haven't run it on muffs in a while but will try again. I have very nice water pressure and initially ran hot on muffs. Went to tank but did not go over cavitation plate hot again. went to a bigger tank and added water over the Cavitaion plate and all is well.

Things could have changed I will try the muffs again and if it is no overheat problem is solved if not I will try tank with water over the cavitation plate. If still hot change the impellor. But if it runs right ... it doesn't make any sense.

no need to run full line pressure on muffs, in some cases it will actually push the muffs away from the motor. and yes, while running in a test tank/barrel/bucket......the impeller has to be submerged as it will not self prime. ( ALL pumps inherently push water much better than they pull water)

 

[clanton]

Re: FLUSHING '87 Ev 90HP - sorry, I need to repost because I think we got off course

You need to pull the water pump and inspect the parts very closely. If I remember correctly the pump has 2 gasket, rubber seal on the plastic housing, o-ring between the impeller cup and plastic housing, and an o-ring between the top of the impeller and impeller cup. Any of the parts defective pump will suck air , when water level is below the cav plate. Using ear muffs water does not cover the pump. I also say the pump does not have to below water level to pump water. When boat is on plane pump is above water line. Service info for V6s address some overheat problems caused by the o-ring between the impeller cup and plastic housing, if o-ring not correctly installed, pump would suck the o-ring out of o-ring groove, then pump would suck air.

The o-ring added later years between the top of impeller and impeller cup for V4/6s air suction problem.

 

[bang4dabuck]

Re: FLUSHING '87 Ev 90HP - sorry, I need to repost because I think we got off course

PART 1 DONE- FAILED on muffs horn came on around 195 on Starboard side. Port reading about 170 before I shut down. Took about 3.5 minutes on MUFFS. Sometime this weekend I will run in tank that I need to jury rig, repair or replace because must have had it in gear at one time and gashed the plastic container I am using. In the past, before the gash, it ran fine and stayed at about 155 - 165 (10,000 RPM around) at idle in the FULL TANK. And again before that would over heat on MUFFS.


PS - I will try again and cut the water pressure to the MUFFS back again and see how she reacts.

Admiral Clanton what say you if she runs proper with water above the Cavitation plate and again hot with MUFFS. I will still need to pull the lower unit and might as well change the water pump. I will also check the water tube to see the condition and make sure it is lined up correctly.

 

[clanton]

Re: FLUSHING '87 Ev 90HP - sorry, I need to repost because I think we got off course

If you keep running it hot, you will need to pull the heads and replace the melted water deflectors.

 

[bang4dabuck]

Re: FLUSHING '87 Ev 90HP - sorry, I need to repost because I think we got off course

So what is a normal healthy temperature ? I will shut it down once it exceeds that. I will consider that a fail if it exceeds. I did recently replaced the deflectors and therms and decarbed the motor on this wild goose chase.