Overheating 1995 25HP E25TEEOR

[Dennise]

Hi,

My '95 25HP "Rude" has ran just fine since I bought it new. I've never had any trouble.

Yesterday, after slow trolling for about 45 minutes, it would not run much over 2500 RPM and with lots of steam spitting out and no tel tale, I quickly went back to idle. I concluded this was an overheating problem and that the S.L.O.W. feature kicked in and limited the RPM to 2500. There was no obstruction at the water intake screens, and the engine felt warmer than normal.

I limped back to the dock at idle hoping I didn't damage my power head.

I inspected the impeller and it looked OK, but the impeller has about 30 degrees of rotational play on the drive shaft. Is this normal or should there be NO play at all?

Next I want to take a look at and possible replace the thermostat. Can someone please tell me how to get at the t-stat on this engine and how to remove/replace it?

Is the impeller rotational play normal?
How do I replace the t-stat?

Thanks in advance.

Dennise

[Sportwin]

The thermostat is located on the cylinder head. Find the spark plugs, they pass through a hole in the "water plate" and screw into the cylinder head. The water plate has approx 12-15 7/16" head bolts. Remove those bolts and you can remove the plate. Be careful when removing the plate, there is a spring between the plate and the thermostat. You may be able to reuse the gasket if you don't tear it. A thin blade knife will help. The rotation of the impeller you described is normal. It uses a wedgie key instead of a woodruff key. The impeller should not turn 360 degrees. Bend the blades away from the impeller hub to see if it is "slipping" on the brass hub. It's possible that you have a blown head gasket. I would replace the water pump and reinstall it while you have the thermostat out. Run it on a flush kit and see if the impeller pushes water up to the powerhead and out the hole where the thermostat sits. That will tell you if the pump is working properly.

[Dennise]

Thanks for the tips Sportwin.

O.K. I took the "water plate" off and removed the t-stat. There was a lot of grunge on it .... I thought maybe enough to stop water flow. Cleaned it up and it opened OK in a pan of hot water. Then I "reversed flushed" with a hose forcing water into the t-stat opening (lower unut removed). The water went in with no resistance and came gusing out where the lower unit attaches. I didn't see any debris or junk come out.

Then I put the t-stat and spring back in, put the water-plate on, reassembled the water pump and bolted the lower unit back on. I put the lower unit in a garbage can full of water filled up to the level of the water pump and ran the engine. I let it warm up until steam was coming out of the tell tale (pee hole) .... I only saw a couple drops of water come out. No pee stream and no joy!

I did note one thing though. There is a 4" long plastic tube about 1 1/2" diameter that sits on top of the water pump that the drive shaft runs through. It has O-rings on both ends. One end fits OK into the water pump, but the O-ring on the other end appears to be too large (in diameter) and the tube doesn't fit snugly into the engine mid section. Could water be leaking here and loosing enough pressure to cause my problem?

I don't see any water on the spark plugs .... they look normal.

I'll try a new impeller tomorrow but I doubt that's the problem. (I didn't get your reply in time to bend the blades backwards as a test to see if the brass hub was slipping)

Help .... this should be easy!!!! I doubt the engine has more than 200 hours on it.

[Sportwin]

The tube your talking about keeps exhaust from going into the top of the pump. Try a little grease on the o'ring before putting it together. When you put the gearcase back on, did you see the copper tube go into the water pump grommet? If the water tube came out when you pulled the gearcase off, did you make sure and install it back into the grommet in the bottom of the exaust tuner up top? You need to know whether or not water is making it upstairs or not. Follow the "pee tube" to the engine and pull the hose off. Make sure the nipple is not restricted with sand etc. When you pull the gearcase back off tomorrow, remove the stainless cup from the plastic housing. There is a small groove in the plastic housing above the cup. That is a vent and if it is restricted with a piece of sand the pump can't pump. Were the pump gaskets in good shape? While your at it, remove the copper tube and blow compressed air into it while holding your finger over the other end. Make sure it's not split and leaking. Then shine a flashlight upstairs and look at the grommet where the tube enters the exhaust tuner. Before you put the gearcase back on, put the water hose on the tube at the bottom, turn it on and see if water comes out the pee tube. Make sure you submerge the gearcase far enough into the garbage can. The water needs to be above the water pump. It can't self-prime, it has to be under water. Let me know what happens.

[Dennise]

Sportwin,

Thanks again for your very good and well written advice. It is possible that the water tube didn't mate properly with the "upstairs" grommet when I reinstalled the lower unit, but I was careful doing this ............ hard to see up there when doing the install. The parts drawings shows a rubber(?) washer on the upper end of the water tube ........ I don't remember seing this ......... hmmmmm.

Tomorrow I'll hit it again with a new impeller and your advice in mind, and let you know.

Dennise

P.S. Should I remove the "exhaust tuner" to see that the water tube mates correctly?

Dennise

[Sportwin]

The tuner is mounted to the bottom of the powerhead. You don't want to pull the powerhead unless that becomes necesssary. With the GC removed, note the position of the water tube then remove it (pull it out). After testing it for a split or leaking, shine a flashlight upstairs with the engine tilted and reinsert it into the grommet, making sure to orient the tube as it was originally. When reinstalling the GC, it may help to have a friend install it slowly while you make sure the tube enters the water pump grommet properly. A pair of storks (long handled needle nose) or a long skinny screwdriver may help. You might have to rotate the flywheel slightly but by the time the driveshaft meshes with the crankshaft the water tube will already have entered the water pump grommet. Good luck.

[Dennise]

Bingo!!

It's likely as you were writing your last reply, I had finally discovered the upper end of the water tube was NOT mated to the rubber "grommet" up inside the exhaust tuner.

Each time I pulled the GC, the tube remained attached to the water pump and so on each re-install, I tried to carefully (an blindly) fit the upper tube end into the grommet as I was pushing the GC up. I check and rechecked everything and concluded it just had to be the upper end not mating. But how to ensure that it is?

Well this is how I did it (alone by the way ............ no one around to help!). First I pushed the upper tube end by itself (detached fron the water pump) and just SLIGHTLY inserterted it into the grommet. This allowed the bottom end of the tube to extend down a little so that I could fiit it into the water pump as I was pushing the GC home. Wala ......... it felt right so I bolted everyting up, attached the flusher muffs and cranked it up. The "pee" stream appeared right away. Took it to the lake and all was back to normal. Original problem ..... junk cloging the thermostat and the tell-take nipple both ... that's all .............. I knew the impeller and WP was OK.

Thanks Slipstream for you excellent tips and suggestions ......... you were "SPOT ON"!!

Dennise