115 evinrude water flow problem

[needmoremoney]

V4 115, 2 cycle 1992 era. Has ran FINE with normal maint last 9 seasons. This season, de-winterized, as usual, it started on 1st crank. Also as usual, i aimed gun at top of heads to check temp-normally has been in 150 degree range. After 3-4 minutes of running, the port head just broke 100 degrees, BUT the starboard head was approaching 200 degrees. NEVER happened before. Tell-tale was shooting its normal heavy stream of cool water, no issue there. (Boat is 100% salt water used, trailered & fresh-water-flushed for 10+ minutes after every single use without ever missing a flush). I removed short hoses from t-stat housing. Port side-cooler side was DRY. Starboard side-HOT side, had SOME water trickle out.

So based on where i'm at, would you guys say i'm looking at clogged t-stats? They are several seasons old. The tell-tale is telling me....impeller is pumping? Was replaced last season.

 

[interalian]

Model number? If a crossflow, the hoses between the heads and thermostat housing are in the water circuit between the pump and the thermostats. If you're not getting any/much water out, you may have a blocked system or displaced/swolen diverters. The telltale gets its water from the exhaust chest which is the first place water goes into the powerhead.

 

[V153]

Remove the three bolts and take the thermostat cover off. Inspect thermostats and poppet valves. Replace if bad. If problem persists ya got something stuck further inside the motor. Like a diverter mentioned above.

 

[needmoremoney]

E115MLESB
so since i'm not going boating tomorrow, i'll pull the t-stats. Any other way besides the cut-a-hole-with-a-dremel-tool way of gaining access to the 3 bolts? I've had no success with ground-down edges on quality wrenches or the snap-on-only swivel...just cant get 'em in there.
Diverter...those are the rubber lines INSIDE the block surrounding the cylinders?
It's a 92-ish motor....that gave me 9 seasons of trouble free use....is replacing the diverter tubes costly? Probably something i'd prefer to farm out....
THANKS!

 

[V153]

ES would be a 1990 motor meaning it's prop rated hp, and has the bubble butt. Yes that does restrict access to the tstat cover. Feel your pain. Once got so pissed off sawed a rectangular hole with a cut off wheel in the bottom of the cowl/pan. Covered it up with duct tape ...

Tried strategically placed holes first, but reckon my aim was off ...

 

[ondarvr]

ES would be a 1990 motor meaning it's prop rated hp, and has the bubble butt. Yes that does restrict access to the tstat cover. Feel your pain. Once got so pissed off sawed a rectangular hole with a cut off wheel in the bottom of the cowl/pan. Covered it up with duct tape ...

Tried strategically placed holes first, but reckon my aim was off ...

​I've done this to other motors too, I figure if it allows me to do the maintenance with less hassle I'm more likely to do it, and nobody ever notices the access point. And if someone does see it, they say "neat idea, I should do that too"

 

[interalian]

This is your water flow diagram:

If you take off the rubber hoses and are getting nothing, the thermostats are not your problem. If the deflector rubber in the block is swolen, it can bock the flow. I made this diagram to show how water gets around. Starts at the water pump, goes to the block, out under the lower cylinder on each bank, loops around the two cylinders then out through the hole in the head gasket, around the head, out the top of the head and into the head cover, then down and out the hose at the bottom of the head.

Water goes through the two oblong holes in the head gasket:

In the "not good" picture above, most of the water would be blocked and that side would overheat. Sometimes the hose swells shut completely or just slips out of its notches. To inspect, no need to remove the head water cover. Just the 10 head bolts and a wire plug plus the bottom hose. It's possible the water cover is plugged with salt too, but removing the ~20 little bolts can be a struggle on a saltee daug.

 

[interalian]

Oh, and removing the thermostat cover on a bubble butt exhaust is doable - need to take the screws out of the back holding the pan to the motor ears then pry down and block it with chunks of wood. Putting it back together - glue to poppets so the springs and tie the springs in place then cut once you have the bolts started. I glued my housing, gaskets and thermostats in with 3M 847 glue and clamped in a vice until set before assembly.

 

[V153]

Fwiw if the blockage is due to something stuck further in. It's entirely possible to pull the head covers and ream or rinse or blow that crap out. Without removing the heads.

 

[interalian]

Fwiw if the blockage is due to something stuck further in. It's entirely possible to pull the head covers and ream or rinse or blow that crap out. Without removing the heads.

Yeah, you might be able to reverse flush with a hose on the bottom of the head.

When I tried to take the water covers off my '82 saltee daug, I broke about 40% of the bolts and scrapped the LC heads. There was no buildup between the water cover and head on that one.

Good thing I was planning to use the high-compression '79 140hp heads from the Saskatchewan lake motor - only broke one out of all of them.

 

[V153]

I broke about 40% of the bolts and scrapped the LC heads.

Copious amounts of PB Blaster combined with patience my friend ...

 

[V153]

Good thing I was planning to use the high-compression '79 140hp heads from the Saskatchewan lake motor - only broke one out of all of them.

From what I'm told those are the 4th out of 5 best heads. Counting down from '76. '80 and after are all the same.

 

[interalian]

From what I'm told those are the 4th out of 5 best heads. Counting down from '76. '80 and after are all the same.

Better than the bathtub heads from the 90hp donor regardless.

 

[interalian]

Copious amounts of PB Blaster combined with patience my friend ...

Except that I didn't care. Just needed the overheat sensors from the '82 heads - they're two-lead vs the single wire ones from the '79.

 

[V153]

Except that I didn't care. Just needed the overheat sensors from the '82 heads - they're two-lead vs the single wire ones from the '79.

Well that's kinda pompous. Regardless. Last I checked '79 and '82 used the same 'sensor', single brown lead?

 

[interalian]

Well that's kinda pompous. Regardless. Last I checked '79 and '82 used the same 'sensor', single brown lead?

Apologies for the percieved pomposity. Since I planned to scrap the bathtub heads I didn't mind breaking bolts just to get the sensors. Now I wish I'd checked whether anybody needed the old heads first and bought a couple of new sensors.

Maybe if I'd spent the time to soak them in PB Blaster I'd have only broken 20%. Still, all I'm saying here is that the 1/4-20 bolts holding the water cover on the head are FAR more likely to break than the bolts holding the heads on to the block. It's a matter of risk, and I'm trying to save the OP the heartache of breaking bolts.

I'd pull the heads off, complete with coils and water covers, and check the diverters. Then I'd backflush the heads using a garden hose to see if removal of the water covers was warranted.




And I can assure you the '82 sensors were 2-lead. Here's a picture of them from before I tore the '82 90hp down.

 

[interalian]

To the OP: re-reading your first post, it isn't clear whether the engine was running when you took off the hoses to the thermostat housing. If you took them off when the engine had stopped, you would expect no water to come out at all as it would all drain out after shutdown.

Do try idling the motor with those hoses off. If you get good and roughly equal amounts of water from each, your most likely problem is blocked bleed holes in the thermostat plate due to some junk you may have picked up from the water. Some advocate enlarging those holes a little to prevent blockage. Some also advocate putting a notch in the poppets to provide a bleed function that will stay clear when the engine is run.

 

[V153]

Never seen sensors in the head cover above the plug like that?

 

[V153]

The pompous thing was kinda a joke ...

 

[interalian]

Never seen sensors in the head cover above the plug like that?

I drilled and tapped for thermo sensors at the top of each water cover, ~15 years ago. Wires from each go up to a SPDT switch on the dash by the temp gauge, and I can monitor head temperature for port or starboard with the flick of said switch. Maybe I'll put a dual gauge in there someday, maybe not.

When I did my up-build, I also tapped and put a water port at the top of each. I'm a bit of a nut, but dual pissers is kinda cool. The port on the bubble butt exhaust just drives the water pressure gauge. Possible downside of the dual pissers tapped off like that is that if the motor ever overheats the water could be scalding (but I don't care about that either...). Certainly have had no problems priming the pump this way.