Normal operating engine temp?

hail mary · **Joined:** Tue Dec 17, 2013 11:50 pm **Posts:** 33

Hello
1996 225 sundowner 5.8efi
What is normal operating engine temp? My boat usually runs at 150 right in the middle , I just got it out of shop after having the exhaust blockage cleared and its running slightly higher, any thoughts....

LouC · **Posted:** Fri Jan 24, 2014 11:41 am

160-175 if with a 160 'stat.

NiagaraChillin · **Posted:** Fri Jan 24, 2014 11:51 am

150 during spring/early summer, then 160 for summer, back to 150 for fall. Water temps can make it move around a bit.

Oh BTW, was it a flapper that had your exhaust blocked?

ric · **Posted:** Fri Jan 24, 2014 12:06 pm

90° water temps in summer I've seen 180

hail mary · **Joined:** Tue Dec 17, 2013 11:50 pm **Posts:** 33

Ok thanks. And yes the flappers were down in bottom of exhaust clogging it up. I will launch today and see how she does

Surface Interval · **Posted:** Fri Jan 24, 2014 9:42 pm

Hail Mary,
My 1995 190 Horizon with a 5.0 EFI Ford engine came new with a 145 degree thermostat. OMC/Volvo used these small block Ford engines up through 1996 or 1997. As I recall during the 1994-1996 time period both 5.0 and 5.8 engines (carb or EFI) used this 145 degree thermostat. The GM engines used a variety of thermostats typically in the 150 to 185 degree range, depending on engine model and year. My 5.0 EFI Ford engine had a tendency to get a grain of sand or debris in the thermostat and hold it open very slightly. This caused the engine to run cooler and never warm up, like maybe 120. Working the boat pulling tubes skiers and then shutting down for maybe 15 minutes to change "victims" on the tubes would occasionally heat soak the engine and open the thermostat enough to release the sand or debris, and then let the engine warm up to 145 again.

So, how does it run after removing the flappers?

hail mary · **Joined:** Tue Dec 17, 2013 11:50 pm **Posts:** 33

Wow launched today and yes! the speedometer actually hit 40mph! what a difference and the rpms go up to 5500 and i didnt have it ful throttle ,,, so yes what a difference clearing out the blockage !

ric · **Posted:** Fri Jan 24, 2014 11:29 pm

hail mary wrote:

Wow launched today and yes! the speedometer actually hit 40mph! what a difference and the rpms go up to 5500 and i didnt have it ful throttle ,,, so yes what a difference clearing out the blockage !

Time for a new prop!

Surface Interval · **Posted:** Sat Jan 25, 2014 12:22 am

Check your engine specs for max rpm range. Mine was 4200-4600 rpm. Check your prop diameter and pitch compared to the original prop for the boat. Try to prop the boat to top out with max rpm near upper end of max rpm range. Just a thought.... you might want to verify that your tach is accurate. I had to have my tachometer reworked because it was reading high. It was reading well over 5000rpm and I was not at full throttle yet. That meant having the gage assembly exchanged. I'm not sure if anyone reworks these anymore. I'm glad its back to running normally again.

hail mary · **Joined:** Tue Dec 17, 2013 11:50 pm **Posts:** 33

yea , with the clogged exhaust I was only maxing out 4500 rpm and not going fast but now it was in the 5000 -5500 range , i will check the prop specs

hail mary · **Joined:** Tue Dec 17, 2013 11:50 pm **Posts:** 33

yea , with the clogged exhaust I was only maxing out 4500 rpm and not going fast but now it was in the 5000 -5500 range , i will check the prop specs

hail mary · **Joined:** Tue Dec 17, 2013 11:50 pm **Posts:** 33

today the boat ran at normal temp and I ran her for 2 miles at a cruising speed of 35mph

NiagaraChillin · **Posted:** Sat Jan 25, 2014 11:29 am

Awesome! Glad your prob is solved. Happy boatin!! Oh, and we need pics, please.

LouC · **Posted:** Sat Jan 25, 2014 2:29 pm

One thing you can do now since its running well and normal temps, is to get an IR temp gun from Radio Shack. Take readings of the thermo housing or the intake manifold right where it bolts on and readings of the manifolds/risers. This will give you baseline of normal temps and will tell you things the temp gauge will not.
With a warmed up engine my temp gauge will say 160-165, intake manifold under the therm housing will say 155, ex manifolds will read 100 or so at idle and will go up to 130 after coming off plane but quickly go back to 100. If I see temps higher than that I start looking for problems.

schoolsOut · **Posted:** Sun Jan 26, 2014 6:46 pm

How did you know your exhaust was partially blocked?

www.iFourWinns.com

Normal operating engine temp?

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