Johnson 115 Temperatures - Again

[Needmorerum]

Thought I would start a new thread for this one, saves building the other one up to much, and slightly different question.
Got the boat back today after having all the gaskets and the O-rings replaced. For a quick reminder, it was overheating when pushed to WOT, then return to operating temp when idled down.
Mechanic took it for a run and everthing went perfect. He did say that he got it to rise in temperature when sitting at around 3k on the Tacho and trimmed all the way down to load it up. He also said that it would probably rise in temp if fully loaded like it was the last time out. 7 POB and a couple of eskies for a day at the island.
He doesn't think that it is a concern, as it isn't getting hot enough to set of alarms.
What are your thoughts, is he right, my wife seems to think I am being to picky, she's always saying that.
Anyway, I've got the boat back for Chrissy, and looking forward to getting out if I can.

Thanks
Corry

[NQCairns]

Hi again Corry, I know I posted to your last post but I cannot remember much about it now, I am becoming extra free with my advice lately so I will keep it up here ;D(too much idle time on my hands lately, looking after a 5 month old).
Anyway, it would bother me! I dont like that feeling when out for a fun day on the water.
When you load it up you are in effect overprop it for the duration, raises exhaust temp and does not so great things to the engine over time, in the future consider a spare prop a couple of inches lower in pitch number for just this occasion, I forget if you posted your WOT RPMs.
You could buy a hand pyrometer to check engine surface temp in real time or buy another guage that uses a sender that touches the engine to help calibrate what is actually going on. Without a real number to go by it is all speculation, it could even be running a bit too cool normally and when the temp rises it reaches its proper running temp, just speculation.
Ooops my girl has just woken up, consider the prop idea if you plan to keep the boat and do a few of those heavey loads. cheers nq

[vp3]

Hi Corry,
I am also the "lucky" owner of a '98 Johno 115hp. I purchased this motor about 2 months ago to push my 17' Seafearer around. I bought this engine off a mobile marine mechanic, he had taken the oil injection capabilities of the engine as he stated they stoped working thus overheating. He stated the engine had been rebuilt with 4 new pistons and rings. Yesterday I took 2 adults and a child for a run on the bay, starting at Victoria Point past Peel Island and almost to the end of the Rainbow Channel where we turned around and went back to Peel and travelled the northern side to the danger mark. We stoped there for 30 minuates and proceeded south to the western cardinal which is just north of the spit beacon (Peel Island) and there was a noise in the motor. I turned around to see steam coming out of the tell tail and great deal of smoke coming from under the cowling. I immeaditly stoped the engine and took the cowling of to promote cooling. I then telephoned (didn't use the radio as not being one to broadcast problems all over the bay) VMR Victoria Point to tow us back, I am a active member, and they arrived in 30 minuates. I thank "C Roster for their great service.
At home I tried to start the motor, it turns over (so is not seized) "phew" but will not fire at all so electrics may have been fried. My motor has 3 months warranty through the mobile marine mechanic so when he diagnoses the problems we will see what happens. I hope the man is honest. I have only had 8 hours on water time with this engine - not even run in...
Corry I hope you have better news than I have, will keep you informed
Cheers Ian

[NQCairns]

98 worst year to buy a Johnson, with OMC no longer bothering with the expense of quality control a lot of rough ones made it into use, would have thought all the problem were found by now?
Might have been just a typical problem, hope you get back on the water quickly.nq

[vp3]

Thanks nq. The mechanic came today and the only conclusions he came to was the impellor is completly intact no plastic was sucked inside and the motor is fried but not ceased. I'll learn more in the new year.
Happy New Year (yea)
Cheers Ian.

[bigbrian47]

ian i've got @ 98 90hp johnson so far the only problem has been the diaphram in the vro system so i had the vro disconnected otherwise a beaut motor
i do the impeller every year @ thermos every second year
it's on a 17ft viking with a 15x133/4 stainless prop
cheers brian

[Needmorerum]

Well, I've go a happy ending to my story. The O-rings were replaced, internals checked, and everything was given the OK. Got it back mid last week, so thought I would burn some fuel over the Christmas period to see how she goes.
I managed to cover 5 hours of running on Monday, thanks to my limited knowledge of how the GPS works, and I did another 6 hours on Tuesday. Not once did the temp go over about 65-70deg, and the motor run like an absolute dream the whole time. I couldn't be happier with the service or the quality from the dealer.

Corry

[vp3]

Thanks Brian it's good to hear that '98 wasn't a complete failure for Johnson outboards. Hope to see you on the bay one day, mines a Ventura.
Corry, sounds great best of luck
Cheers Ian.

[vp3]

Heard from the mobile mechanic today. Head gasket ....PHEW....
This means warranty. There are still some honest ones about.
Cheers Ian

[Needmorerum]

Big Sigh of relief there hey VP3. Hope your not off the water for too long.

Corry

[cooky]

I noticed NQ mentioned RPM at WOT. I've got a 115hp Mercury 2s - 2001 model with Stainless Vengeance prop (apparently matched to boat by boat builders).

Wondering what mine should do. I'm tried to get WOT a few times, but often a bit too rough. Seems to max out at 5200rpm / 5300 doing around 62kph. I have tried trimming it out.

I'm not at home, so don't know the specs of the prop, but should it rev higher or is this okay?

I'm happy with it so not that concerned and not that often I need to have it flat (although I cruised for most of day Monday at around 55k/h (10kts and i was in the mood) from memory doing around 4500 - 4800rpm

just interested to know what it should rev to