Johnson 30 temp gauge

[QuackAddict84]

Hey fellas - I have a 94 Johnson 30 horse model J30ELERM. Does anybody know how, or if, you can add a water temperature gauge to this outboard? I can't find a good place to put a sending unit.

Thanks,
Brian

 

[oldcatamount]

Re: Johnson 30 temp gauge

A "safe" place would be right on the thermostat cover, but, I don't know if there's enough space there.

 

[boobie]

Re: Johnson 30 temp gauge

Before I would install a water temp gauge I'd put on a water pressure gauge. Those older water temp gauges weren't the most accurate at times. With water pressure you know what you've got coming in.

 

[texasabil]

Re: Johnson 30 temp gauge

Before I would install a water temp gauge I'd put on a water pressure gauge. Those older water temp gauges weren't the most accurate at times. With water pressure you know what you got coming in.

Very true I put a temp gauge on mine it would barley move. as someone told me to put a pressure gauge on it. they work great and all the boats and motors I have owned has the pressure gauge!!!

 

[Silvertip]

Re: Johnson 30 temp gauge

More misconception about what a water pressure and water temp gauge tells you. A water pressure gauge merely means the pump is pumping. It has no bearing whatsoever on whether or not an engine is overheating. Obviously without a pump the engine will overheat but just because it is pumping, is no guarantee it will not overheat. In fact many overheating problems are not due to the pump at all. The reason people have problems with temp gauges is because they install the wrong gauge. If the bottom number starts at 100 or 120 for example, then the guage is useless because outboards run cooler than car engines. This is exactly why temp gauges were changed to the C-N-H (cold, normal, hot) range. There are gauges that start at 60 degrees which is colder than the lake water and is the preferred gauge. Temp gauges also use either a screw in type sender or a contact type sender as shown below. Your engine does not have a port in the water jacket into which you can screw the sender so you need the contact type that mounts under a head bolt and places the sender close to the spark plug on the upper cylinder.

Here is the type of temp gauge you need. By the way, if you use a contact type of sender rather than one that screws into the water jacket, you end up with a Cylinder Head Temp gauge. That is even more reliable than water temp. If there is no water flow, a water temp gauge would not register. A contact type will always register.

 

[oldcatamount]

Re: Johnson 30 temp gauge

Wow, thanks for the info Silvertip!

 

[bobjoe1]

Re: Johnson 30 temp gauge

very useful info but could you tell me at what temp a outboard should operate. And at what temp to be concerned about overheating

 

[QuackAddict84]

Re: Johnson 30 temp gauge

Thanks so much. My boat already has a water pressure gauge, but I operate in cold conditions and I want a way to make certain that the motor is heating up properly.

Thanks again,
Brian

 

[boobie]

Re: Johnson 30 temp gauge

If the mtr overheats it should have a warning system already built into it. But Quack I can also see your point too about having enough heat in the mtr.

 

[wilde1j]

Re: Johnson 30 temp gauge

Teleflex Marine has a variety of styles of OB temp gauges and a universal sender, which clamps to the cylinder head or cyl head cover.

http://teleflexmarine.com/wp-content/uploads/2010/05/G13usa-premier_pro_black.pdf

 

[QuackAddict84]

Re: Johnson 30 temp gauge

Hey Fellas - I am having a tough time finding a C-N-H gauge or a contact type sending unit. Anybody know of a place that sells them? I would really like one of the 60 degree gauges, but C-N-H would be fine. I've tried BPS, Cabelas, Overtons, West Marine. It seems that they all just carry the gauge and senders for I/O and I/B applications that use a screw in sender. As always, any help is greatly appreciated.

 

[wilde1j]

Re: Johnson 30 temp gauge

First, you need to get the sender from the same maker as the gauge. I would call Teleflex Marine ... they make a 'universal temp' sender with a bracket similar to that shown above. It has a part number I can't find.

877-663-8396

 

[bob johnson]

Re: Johnson 30 temp gauge

i am an advocate of the temp guage over a pressure guage .....IF .... I were to only have one or the other.

I persoanlly have two temp guages AND a water pressure guage...

I think teh actualy temperature of the motor is the most important...water is there to cool it...but sometimes it isnt doing the job....if you see it overheating... you can shut her down, and save the motor..

if you just look at pressure...you could be UNDER THE IMPRESSION you are not overheating..


my motor spikes once in a while , even with great water pressure....watching a temp guage connected to each head lets me monitor the motor more closely...

overheating is what kills most motors

and they all dont have alarms...

you can buy a temp kit that bolts under any head bolt, like Silvertip posted...

you can have a fantastic water pressure and a clogged carb may give you a lean condition that will over heat your motor....

you could also have great water pressure and a stuck thermostat....

like the tell tale...they are nice and usefull, but not the tell all

good luck

PS to the mod...the instant email notification isnt working..hasnt been for a week at least
BOB

 

[QuackAddict84]

Re: Johnson 30 temp gauge

Bob - I am looking for one of the "under head bolt" temp gauges, but I'm having trouble finding anybody that carries them. I have been told to contact teleflex, which I have not yet done. Before I go straight to the manufacturer, do you know anybody that sells them?

 

[bob johnson]

Re: Johnson 30 temp gauge

for sure one of the hardest things I have ever tried to find for my boat and or motor....

temp senders


lots of people sell teh gusges, but they dont say if the guage comes with a sender..

SIERRA sells hundreds of senders......but they dont say which goes with which gauge

i have seen KITS at WEST MARINE that had the guage and the sender...

just keep looking...

a few years ago I had read, you need to make sure the sender sends in the right ohms as the guage reads....

certainly hard to figure out, if you are buying seperately( i had the guages and one sender.....was a nightmare just trying to find a DUPLICATE sender


good luck

bob

 

[Silvertip]

Re: Johnson 30 temp gauge

Quack -- you have a private message.