1993 Johnson 115 measuring head temps with IR gun?

rothfm

Ensign
Joined
Sep 26, 2006
Messages
915
Hi,

I believe I'm ok with appx 135-145 shooting around the head covers and heads. Some places down low are 115-125. But mostly I see 135-145.

But, If I aim deeper toward the inner/back of the piston area...I can see temps in a couple spots at 150-161. Is this normal, if the areas around and on the heads are aok? Where should I be measuring to ensure I'm ok?

Sensors/alarms are aok and I just did bubble back tstats, head gaskets etc..The head have good flow out the hoses. Maybe I'm just bieng a worry wart!!

Thanks
 

Bosunsmate

Admiral
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Apr 7, 2012
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6,135
Re: 1993 Johnson 115 measuring head temps with IR gun?

160 would be fine with me, is that at idle?
 

rothfm

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Sep 26, 2006
Messages
915
Re: 1993 Johnson 115 measuring head temps with IR gun?

160 would be fine with me, is that at idle?

hi, Ya-on muffs. The prior owner had t-stats out for some reason. I did some work and initially liked the readings till I saw a couple spots in(forward) of the heads at 155-161 degrees...Both sides, other than that most of the locations I shoot are 120-145 depending on location. I think I'm good I HOPE!
 

rothfm

Ensign
Joined
Sep 26, 2006
Messages
915
Re: 1993 Johnson 115 measuring head temps with IR gun?

Oh, and I did the deflectors as well, were flat. Just curious of the higher temps in a few spots.
 

toddschubert

Chief Petty Officer
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Sep 3, 2011
Messages
504
Re: 1993 Johnson 115 measuring head temps with IR gun?

Mine reads same way. For monitoring purposes I put a temp gauge in w sensor on top of t stat housing centered. It works great gives same temp as I'd gun. You won't know what side is hot but the alarm doesn't tell you either
 

rothfm

Ensign
Joined
Sep 26, 2006
Messages
915
Re: 1993 Johnson 115 measuring head temps with IR gun?

Thanks Todd, Remember you did that when we talked about my 88spl. Thanks. Good to know it seems normal.

Might be a water test today.

I really want to do that at some point, I have room for 2 small guages and will monitor each bank.
 

toddschubert

Chief Petty Officer
Joined
Sep 3, 2011
Messages
504
Re: 1993 Johnson 115 measuring head temps with IR gun?

dual guages would be the best thing to have good luck
 

rothfm

Ensign
Joined
Sep 26, 2006
Messages
915
Re: 1993 Johnson 115 measuring head temps with IR gun?

UPDATE: Continued monitoring and starboard side, runs hottoer even on the head (149-154) than the Port. Good flow out hoses and thru exhaust leg. I still suspect one of the Tstats bought on Ebay. Going to get OEM stats this week and swap again.

bubble back, but I've done it twice now successfully, with extra hands!! I'll update if this drops the bank down to 143+- as i expect.
 

mrmamiller

Petty Officer 2nd Class
Joined
Mar 7, 2011
Messages
167
Re: 1993 Johnson 115 measuring head temps with IR gun?

I have a 1986 110HP Johnson. My starboard side runs hotter by about 5 degrees. I don't worry about it, as I went through a lot to get it to where it is now. I have temp sensors epoxied near the overtemp switches so I can watch the temps as I run the boat on water (not so easy with the IR gun). My hottest temps are at idle, which is what I was looking for, as they were way to cold before doing a thermostat job. I can now run for hours at low speed in gear without a hickup. Yeah, bubble-back is a real treat!
 

rothfm

Ensign
Joined
Sep 26, 2006
Messages
915
Re: 1993 Johnson 115 measuring head temps with IR gun?

Hey, thanks for that...make me feel better. I'll get buy the new stats but maybe wait to do an in-water test vs just the muffs. not an easy chore to do em. See what happens first.

thanks again.
 
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