Evinrude 15, 1980 water circulation

[Mikko]

I have two of those 15 Evinrudes and I am not sure whether the water is circulating properly. In one of these motors there is good water pressure from pee hole (straight water line) while idling and it increases a bit with increasing throttle, but it seems that with full throttle there is an intermittent flush occasionally. Does anybody guess where this problem most likely locate? The water pump is brand new and everything seems to be ok in the lower section. I think the problem cannot be in the power head since it should increase the pressure in the pee hole. Another question concerns the seal at top of the pump around the drive shaft. How much this seal can affect the pressure in the pee hole? In another Evinrude this seal (even though a new one) is not very tight in the impeller housing and when I pulled the gearcase, this seal was not in place. The pressure is quite low in this motor, but still everything seems to be ok. What about the grommet in the upper end of the copper tube?

Mikko

 

[oldboat1]

tell-tale/pisser can distract. Try to clear obstructions with a wire. Check the temp of the engine -- hot to the touch? An infrared gun is useful, but can hold the heel of your hand on the top of the head to check -- if can hold it for a few seconds, but then feels too hot, you are probably fine (about 140 degrees). If temp is too cold or too hot, may need to service t.stat down at the bottom of the head -- wouldn't do that unless you have temp problems because it's kind of tough to get at, but shouldn't hesitate if needed.

 

[Mikko]

I changed the head gasket, thermostat and the thermostat cover gasket, they should be fine.

 

[raczekp1]

locked grommet at the top of water tube can do this problem.
very common problem

 

[Mikko]

I tried with another lower unit from similar Evinrude 15 (good water pressure) and it did not help at all. So, the problem is neither in the lower unit nor in the upper power head. Grommet at the top of water tube must be the case. If am going to check the grommet, how difficult it is to take the power head out only for this purpose?

 

[Mikko]

Does anybody know how warm the water from pee hole can be in this Evinrude? And if it is too warm, what can be the reason. A lot of water is also coming out from the exhaust relief in the mid-section right after the start (soon after the pee hole). I think sooner than what could be expected concerning the thermostat opening.

 

[raczekp1]

i think upper water tube gromet is problem
look here:

 

[oldboat1]

An intermediate step might be to pull the l.u., and force water up through the motor through the water tube. Motor shut down, of course. I often do this on motors I'm working on to clear whatever blockages or debris I can. If your motor is running at normal head temp, though, wouldn't be concerned.

 

[jrs_diesel]

I had this happen to my 86 Johnson 9.9. Very little water out the tell tale. Would steam while running. New water pump didn't help. Hooking up a garden hose to the water tube gave a false positive indication of good water flow (hose pressure forced more water past the obstruction than the water pump ever could).

Turned out my problem was the upper water grommet. The grommet had swelled near completely shut, letting very little water through it. After replacing that and reassembling, the cooling system works great and the water indicator has a solid stream out of it. The indicator stream will feel warm once the engine is warmed up, it's tapped off the engine on the exhaust side.

Here's a detailed write up I did when I fixed mine, post #5 in this thread:
http://forums.iboats.com/forum/engi...utboards/646849-85-15hp-evinrude-over-heating

 

[Mikko]

Thanks for the information

 

[oldboat1]

Mikko -- I routinely use a small hand pump (transfer pump) with a small hose to fit the water tube. A garden hose will produce too much pressure. I also use the small pump if the head or exhaust cover is off to flush around and downward through water passages. If it's a grommet, then that will finally be the fix.

 

[Mikko]

No Title

Two Evinrudes are seen in the figure. Left one is 1982 and right one 1980. They have different exhaust tube and in the LH one there is a short outlet water tube and, therefore, at least I think, much less water is coming out from the exhaust relief in the mid-section. Change of the grommets will be the next step.

 

[Mikko]

I started the powerhead removal and everything is ready now except the tiller arm throttle shaft/linkage. I could not figure out how it must be opened for powerhead removal?

 

[jrs_diesel]

If it's where the cable attaches, it's just a ball and socket connection. Pops off with a little bit of force.

 

[Mikko]

There is no cable, I think if I am pulling the powerhead out of the lower cover, I need to separate the throttle linkage to the tiller arm?

 

[OptsyEagle]

I just pulled the powerhead off of a 1976 model so I suspect it will be the same but cannot be sure.

The timing plate has a metal piece that comes out and is connected to a vertical rod and held by a cotter pin. That cotter pin needs to be removed. Also, the vertical rod is connected to the powerhead by being sandwiched inside two brackets. Those brackets are connected to the powerhead by two bolts. Those two bolts need to be removed.

That should disconnect the throttle/tiller arm from the powerhead.

 

[OptsyEagle]

By the way, those two motors look pretty identical. Both look like 1980 models. Neither look like a 1982. At least the covers look like 1980 motors, but also the mid-sections. Do they have different model numbers?

 

[jrs_diesel]

Oh wait, you have the shaft and gear type throttle correct?

I've only disassembled one of those on my 6 HP Johnson. If I remember right, once I disconnected it from the timing plate arm, the vertical shaft just pulled up and out.

 

[raczekp1]

to lift powerhead you need to loosen 9 bolts + 1 bolt from gear tension selector.
you dont have to play with trotle handle when takeing out powerhead.
if you lift powerhead everything will vertical go up
when putting back its be careful with this vertical trotle shaft.it should fit in squere noth

 

[raczekp1]

to lift powerheads in 9.9/15 hp motors i use crowbar.
I slowly play with crowbar from carb side and from rear side(where spark plugs are screwed)