Cool water telltale on muffs.

[alzoe]

Good morning all. Longtime reader, first post.
One year ago I bought a 1999 Sea Hunt 172 cc with 1999 Johnson 115 hp, J115PLEEM. All has been relatively fine during the year with about 15 outings in salt water in SC.
Yesterday, after fishing, I flushed the motor on muffs. After a few minutes I felt the water of the telltale and it was cool. Quite cool. I shut off the motor and as the remnant water came out it was very warm. Turning the motor back on the water again was cool. Motor off, remnant dribble very warm. Putting my hand on the motor heads was not extremely hot and I could keep my hand there.
I remember many months ago feeling the telltale stream and it was hot. The stream is and has always been very strong.

Should I be concerned or is this normal?

Thank you for reading and thank you in advance for any comments.

--al

 

[tedious]

Re: Cool water telltale on muffs.

When you felt the stream many months ago, was that in the driveway on muffs, or on the water? My telltale never gets very warm in the driveway - not as much heat being generated at idle, and running on muffs, you're pushing a lot of water through; it's not in there long enough to pick up much heat. The last few dribbles have been in there long enough, that's why they're hot. The bottom line is that I don't think you have a problem.

That said, if you have not replaced the water pump and thermostat for a while, or don't know when it was last done, maybe it's time.

Tim

 

[HybridMX6]

Re: Cool water telltale on muffs.

I agree with tedious, if you don't know the last time this service was done, I'd be looking into doing it soon, just to be safe.
It sounds normal to me though, as for the temp of it. When yo have it on muffs there is a lot more water pressure going through there then usual, so it comes out faster as well, and thus does not absorb as much water as when running in the water. Same applies for the speed. On muffs you should not rev it over 1500rpm's or it could "run away" on you, but obviously in the water you have full rpm's to work with, so it's going to generate a lot more heat.
Another thought is the water temp itself has cooled down a lot since summer months, which could also be a factor.
I fish saltwater myself, and drive past a freshwater river on the way home, where I stop in and run the motor to flush it out and rinse off my boat/trailer. It never gets more than warm when doing this, but I am not using full rpm's either since I'm stationary, I leave the boat on the trailer for this.

 

[alzoe]

Re: Cool water telltale on muffs.

Thanks for the quick reply guys.
The po told me last year that he replaced the lower unit 2 years previous. I don't remember if he serviced the pump but if he did then it would be about 3 years now.
I occasionally feel the telltale when on muffs and usually it's warm to very warm. many months ago I do remember it being very hot on muffs.
Yesterday's event was unusual enough to startle me.

Could the thermostats be sticky?

 

[WIMUSKY]

Re: Cool water telltale on muffs.

I agree with the other guys too. When you run it on muffs it should run cool because you're constantly pumping cold water. Much colder than when you run it on the water. Sounds like you're having an intermittent problem. I would change out the thermostat and see if the issue is resolved.

 

[HybridMX6]

Re: Cool water telltale on muffs.

if it concerns you enough, just replace the t-stat to be safe. If I was honest, I'd do the water pump as well. It seems a very daunting task, but it's really not that hard to do. You just need the factory manual and the water pump kit. My 1st time took me about 3 hours to do, start to finish, and that included having to Dremel off the old impeller as the brass collar in it was frozen to the shaft. Once it popped off, I cleaned it up, put on new water pump kit, and re-installed. It was all for peace of mine, nothing was showing signs of needing to do it, but it has been in there for 4 years and I run in shallow water all the time, including through an occasional sandbar (not on purpose), so I felt it should be done for reliability.

 

[alzoe]

Re: Cool water telltale on muffs.

Thanks everybody.
I have done this job on an '80s 15hp johnson about 20 years ago, it was fairly easy but the 115hp does seem "daunting".
I will buy "the" Johnson service manual and get on it.

1) Is there the same problem of lining up the shifter linkage shaft?
2) Is there a gasket between the lower unit and mid section?
3) Are the thermostats easy to replace or is this a pro shop job?
4) Can/should the thermostats be tested first?
5) Should I replace the entire pump assembly or just impeller?

Have a great weekend, tight lines !

 

[Boss Hawg]

Re: Cool water telltale on muffs.

Try it in a barrel

 

[kenmyfam]

Re: Cool water telltale on muffs.

Check head temps at normal temperature. If water pump is an unknown quantity then service it immediately. It should be part of routine maintenance.

 

[alzoe]

Re: Cool water telltale on muffs.

Good morning everybody.
I went fishing in the boat out Saturday and the telltale stream was strong but water was barely warm, lukewarm, if you will. Probably not even 100* F.
Would you seasoned mechanics conclude that the thermostat is not working?
I am certain that last winter or spring I felt hot water even on muffs.
I never get any overheat alarms and the motor runs well except I get that "classic vapor-lock" poor idling and stalling when restarting after sitting and fishing for awhile. If I high idle in neutral for a minute then it will idle normally and all becomes good again.
So I wonder if the T-stat problem(if it is malfunctioning) is causing too much heat and "fuel boil-off" when restarting after sitting.

Today I will stop by the shop and buy the book, pump kit and thermostat.
I'll also get some LU gear oil.

Thanks everyone for your inputs.

--al

 

[alzoe]

Re: Cool water telltale on muffs.

Goodmorning.

I'm reluctant to blindly spend 60+ bucks on two thermostats. Can someone inform me how to check/test them?

As stated above the **** stream is very strong but barely warm on the river and in the driveway on muffs. I can keep my hand on the heads for multi-seconds.

Cheers!

 

[G DANE]

Re: Cool water telltale on muffs.

Hi alzoe

A thermostat can be tested by putting it in a glass with cold water. Pour cooking water over, and when the water will be over the designed temperature, they should open. If no movement is visible, they are probably stuck open, which i suspect one of them is. However changing them now and then should be looked opon as insurance, and who isnt willing to spend 50 bucks on insurance of a powerhead burndown that will kost you like 3000 bucks. Besides they are a little hard to get to, because of the bubble back exhaust, so my advise would be to put a couple of new in, now they are out anyway.

 

[alzoe]

Re: Cool water telltale on muffs.

G-Dane, et.al., thanks for input. I'll try that T. test.

I went to the dealer/shop yesterday to buy 2 t-stats, book, water pump and a few other items. I was told that my motor's( J115PLEEM) telltale is supposed to be barely warm and if I experienced hot water last winter then there was a problem that went away spontaniously. They said not to waste money on thermostats. So I bought only one.

Also, I described to him my poor idle and stall upon "warm re-start". I told him that I've read(here I think) that this is a "classic symptom of vapor lock" that these 60 degree motors have. Particularly 90 - 150 hp motors. Solutions include: High idle in neutral for a couple of minutes, squeezing bulb, and a perfectly tuned engine.
He said, "That is most likely the vapor pump of the vapor separator unit". Huh ? First time I've ever heard of that.
Today I searched vapor separator and pump on this forum and there's a lot of good info. Great stuff. I 've learned much these past few days.
Anyways, since there's many motors out there with similar, if not exact, symptoms I thought it incumbent to pass the info on. The diaphragm of the vapor pump tends to tear and replacing that is only about 3 dollars.
I should probably start another thread on the warm start topic.

 

[Knightgang]

Re: Cool water telltale on muffs.

Great info on the subject. I hope that others get great benefit from it. Let us know if it makes a difference on your motor...