OVERHEATING on MUFFS but not in a tank that covers the vents - '87 Ev 90HP

[bang4dabuck]

Just doesn't seem right that this is normal. I was told by an Evinrude technician ( Don, he seems pretty knowledgeable) that there is probably a problem with the WATER TUBE or the WATER TUBE GROMMET.

1) Do you concur that it should not overheat on muffs with sufficient water flow?

2) It seems if the tube is bad or just disconnected not too hard a fix. A hassle maybe but no biggie. The Grommet on the other hand opens a can of worms seeing as though I just sold my cherry picker.

a) Is there any trick to avoid pulling the head to replace a freaking $3 piece ???

b) Any way to insure that the Grommet is in need of replacing ??? BAD GROMMET ??? Water showing up in the LOWER ENGINE COVER say . Any sure signs ???


thanks

 

[Joe Reeves]

Re: OVERHEATING on MUFFS but not in a tank that covers the vents - '87 Ev 90HP

On a flushette, the water must be turned on full force, otherwise the water pump can work its way into an air pocket.

 

[bang4dabuck]

Re: OVERHEATING on MUFFS but not in a tank that covers the vents - '87 Ev 90HP

Thanks Joe. Nah I actually have it in a tank and :

a) when water only comes up to top of gear casing it overheats

b) when water is up higher and covers the VENTS over the gear casing it stays much cooler.

Anyway to know if the GROMMET is bad or maybe out of position, without pulling the power head ? Water some place it shouldn't be or lack of water pressure ???

thanks

 

[clanton]

Re: OVERHEATING on MUFFS but not in a tank that covers the vents - '87 Ev 90HP

What vents?????????????????????? Do you mean the water pickups?

 

[phipps]

Re: OVERHEATING on MUFFS but not in a tank that covers the vents - '87 Ev 90HP

a) when water only comes up to top of gear casing it overheats

b) when water is up higher and covers the VENTS over the gear casing it stays much cooler.

thanks

Right there's your problem, those "vents" are the water intake. They have to be covered by water.

If you've run the engine very long without them covered you could possibly have damaged your impeller.

 

[clanton]

Re: OVERHEATING on MUFFS but not in a tank that covers the vents - '87 Ev 90HP

Are these the exhaust vents rear of exhaust housing. If so when the water level is this high it covers water pump housing, which means the water pump is sucking air when the water level is below the pump. Replace water pump with complete kit.

Then check thermostat and water pressure releaf valve. The valve will stick in the rubber grommet. Clean block, replace grommet, insert valve should move freely. If the plastic valve does not move freely. file the little fins on the valve down until valve moves freely.

While thermostats and valve are out of block, run engine in water tank, water should gush from the block. If water does not gush from block, back to water pump and water tube.

Still overheat, remove heads, replace water defectors.

 

[Joe Reeves]

Re: OVERHEATING on MUFFS but not in a tank that covers the vents - '87 Ev 90HP

The water pump is attached to the top surface of the lower unit.

The water pump is NOT a self priming pump... therefore the water level must be above the location of the water pump in order for it to function.

If you have been running the engine with the water level below the water pump location, drop the lower unit and repair/replace the water pump assembly.

 

[bang4dabuck]

Re: OVERHEATING on MUFFS but not in a tank that covers the vents - '87 Ev 90HP

The vents I am talking about are right next to the ANODE (59 in this breakdown) and I was wrong, These vents are also part of the gear casing but not where the flushette would mount.

http://shop2.evinrude.com/Index.aspx?s1=v35446878b3vsdgl2hm260tuv1&catalog_id=0&siteid=1

SEE ATTACHED

I recently replaced thermostats. I also have a water pressure gauge hooked up. I can replace impellor. I mean it hasn't had that much use but has been in for about 2 years.

I just hate replacing parts blindly and especially the GROMMET unless I know it is the problem. Get my drift ?

Maybe it is already determined that I am way off base and those vents need water going thru them and I stand corrected. But then I can't use the muffs to rinse my engine and that can't be right ... RIGHT ???

thanks

 

[Joe Reeves]

Re: OVERHEATING on MUFFS but not in a tank that covers the vents - '87 Ev 90HP

Those vents are actually the thermostat water relief outlets. No water enters those areas... water exits those areas but only when the thermostat(s) open.

Notice the top surface of the lower unit where it joins up to the long exhaust housing.... you need the water about 3" above that joint to cover the water pump in order for it to function.

The actual water intake area is further down the lower unit area.

You either need a bigger bucket or jack that bucket up with some wood block spacers.

 

[bang4dabuck]

Re: OVERHEATING on MUFFS but not in a tank that covers the vents - '87 Ev 90HP

Thanks Joe

So are you referring to the MOUNT BRACKET COVERS on the MIDSECTION (number 10) ? These need to be covered with water ?

http://shop2.evinrude.com/Index.aspx?s1=v35446878b3vsdgl2hm260tuv1&catalog_id=0&siteid=1

If so you cant use muffs to flush saltwater out ??? And if so that would rather suck !!! Hey but at least I wouldn't have to pull the power head to replace a $3 part. So I guess you need a nice size tank to flush. WOW !!! How convenient !!!

Should I replace the impellor now ? That's a pain too getting that SHIFT ROD engaged properly when reinstalling. Any tricks to that Joe ?

 

[Watermann]

Re: OVERHEATING on MUFFS but not in a tank that covers the vents - '87 Ev 90HP

Reading your original post here I have to say... Water tube and grommet? Pull the power head? I think he's referring to the tube coming down from the powerhead that goes into the top of the water pump where there's a grommet. If on muffs then water would just spew out above the pump and not make it to the powerhead.

 

[Joe Reeves]

Re: OVERHEATING on MUFFS but not in a tank that covers the vents - '87 Ev 90HP

So are you referring to the MOUNT BRACKET COVERS on the MIDSECTION (number 10) ? These need to be covered with water ? http://www.**********/parts/search/BRP/EVINRUDE/1987/E90TLCUR/MIDSECTION/parts.html
If so you cant use muffs to flush saltwater out ??? And if so that would rather suck !!! Hey but at least I wouldn't have to pull the power head to replace a $3 part. So I guess you need a nice size tank to flush. WOW !!! How convenient !!!Should I replace the impellor now ? That's a pain too getting that SHIFT ROD engaged properly when reinstalling. Any tricks to that Joe ?

On your engine... look further down the lower unit below the cavitation plate, see that plastic or nylon type screen there? That would be the water pick up. The ear muff type flushette clamps on that nicely.

That hyperlink takes me nowhere.

I assume you know where the water pump is.... the water must cover that area when in the water. Yes that would mean having the water covering the lower side motor mount brackets.