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Johnson 115 Speedo and water pressure gauge questions

J

johnbrock

New member
I have a couple of minor questions about my Johnson 115/OMC Javelin 389 boat.

The model of the Johnson 115 motor is J115TLERC. The questions are as follows:

1) I have looked endlessly on Google to try and figure out where the speedometer hose connects to the motor (the hose is now hanging loose, but putting air pressure in the hose does cause the dash gauge to pop up. So the gauge is not blocked and is working properly). The postings have not pinned it down for me. Nothing they show seems to match up with my motor or the photos are not clear enough.

2) Same with the dashboard-mounted impeller water pressure gauge. Gauge and hose are OK but again I can't find where the hose connects to the motor?

3) Last but not least, assuming the motor is OK (hull is in good shape), what can I expect the top speed of this boat to be?

Thanks so much in advance for any help. - John
 
WHat year? - the Speedometer does not go to the motor - it will go to a transom mounted water pickup tube (pitot) on the bottom of the transom. As for the impeller pressure...I havent had much experience with those - Im guessing it would need some sort of pressure sensor like this->
P1090147.jpg

As for Speed - that depends on boat weight, cargo weight & distribution, and prop size/pitch. First guess would be 45-50.
 
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Ha...I just did a quick search on water pressure guage .....I imagined something similar for the pressure so I grabbed it... - I did think it was a weird design going straight into the cover like that with nothing sealing it. Looking closer I cant believe I didnt recognize it as temperature I didnt even see the wire connected to it...been a long day.
 
You may have to mount a pitot tube pick up on the transom for your speedo. The motor doesn't seem to have one.
 
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Progator135 said:
Ha...I just did a quick search on water pressure guage .....I imagined something similar for the pressure so I grabbed it... - I did think it was a weird design going straight into the cover like that with nothing sealing it. Looking closer I cant believe I didnt recognize it as temperature I didnt even see the wire connected to it...been a long day.
Click to expand...

What you end up doing is taking a T fitting that has 2 X 1/4 inch and a ~3/16, and putting that inline with the telltale hose.

I just did this a couple days ago on my 110. Works *OK*, never going to be as good as something on the block but does give me a reading that would help indicate problems.

On my Johnson 150 60-degree's, they were nice enough to give you a fitting for pressure, and a temp sensor hole on each head. That was a much better setup.

Jon
 
Couple more bits of information on my posting. I’m pretty sure the speedo hose connects to the motor. Have seen a few pictures of the supposed connection point on the motor on google, but was unable to make out the connection point or understand their description. The other factor is that this motor came with this Javelin boat and there is no sign of a transom-mounted speed pickup and no holes drilled-or-filled in the hull that might have been where one broke off. The hose from the dash speedo now runs to the back and hangs loosely at the engine.

Also, the water pressure meter came as a mounted item in the dash. This hose also goes to the back and is hanging loosely right in front of the motor. So I’m pretty sure it was at one time connected to the motor’s water jacket somewhere.

Anyhow, I thought a little better description might help on solutions. Thanks all. - John

 
johnbrock said:
Couple more bits of information on my posting. I’m pretty sure the speedo hose connects to the motor. Have seen a few pictures of the supposed connection point on the motor on google, but was unable to make out the connection point or understand their description. The other factor is that this motor came with this Javelin boat and there is no sign of a transom-mounted speed pickup and no holes drilled-or-filled in the hull that might have been where one broke off. The hose from the dash speedo now runs to the back and hangs loosely at the engine.

Also, the water pressure meter came as a mounted item in the dash. This hose also goes to the back and is hanging loosely right in front of the motor. So I’m pretty sure it was at one time connected to the motor’s water jacket somewhere.

Anyhow, I thought a little better description might help on solutions. Thanks all. - John

Click to expand...

Are you really sure the engine was stock on that boat? It's pretty common for someone to swap an engine out, in which case that is what would happen (cut hoses, leave dangling)..

There *might* be a pickup for the speedo on the top of the lower unit someplace (you would need to remove it to check). As has been pointed out, folks do not think that engine came with one, but if there was one that's where I'd expect to see it.

As far as the water pressure gauge - if you had an unused fitting on the engine that wasn't connected to anything, and you ran it, you would know :).

Jon
 
Judging by the model# your motor's a '94(?).

IF your gearcase has the built in peetoe it'll look like so: (Highlighted in black) Hole in the leading edge of the case ~2" above the "bullet". With a hose nipple that threads in just below where the case joins to the mid.

Perhaps this fitting's been sheared off? It happens, they're plastic.

If'n the pressure gauge hose is hanging loose a minute or two of running the motor oughta tell ya where it's posed to connect?

For a top speed estimate you'll have to supply us with length, weight, etc, of your hull.
 
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Hang on. Can't get the effen pic to load ...

Okay. There we go.
 

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71V, what HP motor is that pic of ?? According to parts diagrams the 115 HP didn't have the pick up but the bigger HP motors did.
 
My bad Boobie. That one's offa '83 140.

Just sold one from a '92 88 special and it had that hole/fitting?

'Course I never checked part #s to see if it was original to the motor?
 
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