Johnson 115 crossflow has hot spots after WOT runs.

[sutor623]

Thanks for the update. Poor fella. He was the real deal, for sure.

 

[89retta]

I think boobie nailed it. As soon as you shut the motor off you have no waterflow to help cool it and the temps will rise

 

[sutor623]

I think boobie nailed it. As soon as you shut the motor off you have no waterflow to help cool it and the temps will rise

Yea you guys are probably right. The temps def do rise after shutdown.

I just remember hearing the number 120 degrees at WOT, but I guess that is just head temps.

 

[Fed]

From my '88 model 90HP manual tan wire.
switch closes at 205 degrees +- 6 degrees.
switch opens at 162 degrees +- 15 degrees.

From my OMC trained outboard guy.
At WOT there is so much water flowing the thermostats will start to close to keep the temperature up.

Here's an extra from my manual which I assume is quickstart.
White/black wire.
switch closes at 96 degrees +- 3 degrees.
switch opens at 89 degrees +- 3 degrees.

Edit: I think120 degrees at WOT can't really happen because the thermostats would be closed.

 

[interalian]

On a ~78-97 crossflow V4 (sorry, the only system I'm really familiar with), the thermostat holes are tiny compared to what the poppets must flow at WOT, so I can't see how them closing would make a huge difference. That said, I'm not the engineer who designed it and will go with the OMC trained guy. I notice on mine, the temp gauge usually sits between 120 and 130 any time I'm on plane regardless of throtttle position.

 

[Fed]

You could be 100% right interalian, that edit I put in was an assumption on my part.
That will teach me, I should have stuck with known facts from my Manual & Outboard Guru.

 

[interalian]

I think mine runs cold in general, but water temperatures around here are usually quite low - maybe 60-70F. I suspect source water temperature plays a considerable part in running temperatures.

 

[SpeedCraft]

Frankly I don't think there's a problem. Believe y'all are overreactin ...

 

[sutor623]

Thanks for the info on the switches FED.

Interalien, where are your temp sensors located for your temp gauge?

 

[interalian]

As some around here know, I went a bit overboard (lol) with temp senders and pissers. Each head cover is tapped 1/4" NPT in two places and has a sender and pisser elbow. I put the sender at the top where the water flows out of the head to the cover as there's space for the sender tip. I have a SPDT switch so I can look at port (2/4) or starboard (1/3) head temp on the fly. I usually keep it switched to starboard since that's usually the one that overheats first.

Having the pisser fittings up high should help bleed the system, not that I've ever had problems with that.

 

[sutor623]

Wow, yea you weren't playing around were ya? Looks good tho...........

 

[interalian]

Thanks. There's no kill like overkill.

 

[Fed]

Sutor fwiw my 90 crossflow had a temp gauge sensor into a hole that looked factory, have a look at the 'thing' just above the red circle you put into the very first picture in this thread.

 

[sutor623]

Sutor fwiw my 90 crossflow had a temp gauge sensor into a hole that looked factory, have a look at the 'thing' just above the red circle you put into the very first picture in this thread.

Ok buddy, will do.

This motor has a jet foot on it. If you lodge debris up into the jet pump it can block water flow. A temp gauge on a motor like this is a good idea.

 

[sutor623]

Hey guys,

Thanks for all the ideas and suggestions. I ran the motor hard this weekend for about a 7 mile run and pulled the hood. Head surfaces were 130, top of block 150. No overheat alarm. Think Im good guys!!