1997 Force 50 HP cooling problem

[Kodiak1513]

Have a 97 Force 50 HP on fishing pontoon, has always ran perfectly. Started to overheat, new impeller this year will run all day at 1000 RPM's but if you run any faster water stops flowing out of tell tail and heats up. Strong flow from tell tail at 1000 rpm any ideas I love this motor has never let me down before.

 

[jerryjerry05]

The old impeller when removed, was it in 1 piece?
All the vanes still in place?
​Fresh water or salt?
You run in shallow water or hit bottom?
​The whizz tube just tells it's getting water up to the head.
Possible the themo isn't opening??

Get a heat gun and make sure it's really getting hot.
Your thermo should open at 130d.
​You can test the sender and the thermo.

​You sure the pump housing connected to the down tube?
​All the parts there?

It takes 5 posts to add pics.
​Unless you use a pic sharing site.

Oh yea WELCOME!!

 

[Kodiak1513]

Yes impeller was find, I replace it every other Spring also replaced plate this year. Only used in freshwater since new (same Lake) kept in covered lift when not in use.Never run in shallow water, i use trolling motor in shallows motor up. Will pull thermo and recheck down tube on Tues. Wouldn't still have water out of tell tail with stuck thermo.

 

[Kodiak1513]

I pulled thermo, started at idle, water pouring out of hole for thermo, tell tail and the 2 holes on rear. Pulled Impeller, everything looked OK. Put back together lowered back in water restarted water OK at 1000 RPM's, took up to 1500 RPM's water starts to spit out of tell tall. Took up to 2000 RPM's water stops coming out of tell tail and two holes at back, this is with no thermo in motor. Starts to heat up and warning buzzer comes on. Everything look clean behind thermo, also pulled the plugs and they looked find. Took it down the lake for about an hour at 1000 RPM's , no problem ran find. Don't know where to go from here

 

[Jiggz]

Do you still have the old impeller? Is it still intact? Do a side by side comparison of the old and the new be crucial with the height. If identical, verify shaft key is in place. Since you also replaced the plate, verify it is the correct one. If you still have the old one, do a side by side comparison be crucial of the alignment

 

[jerryjerry05]

You gotta have the thermo in there to stop or restrict the flow or it won't come out the whizzer.
No restriction no flow.

The sensor can be bad?
Get a heat gun and see if it really is hot??

 

[Kodiak1513]

I have the last 5 impeller ( 47-85089 10 ) all are the same, base plate 8821354 2 that is what service manual calls for. Motor is getting hot you can smell it, I ordered a new thermo new pump kit and bottom seals I will try again. Will also check the exhaust, the bubbles seem to be coming out the 3 slots on both sides just above the gear housing,

 

[jerryjerry05]

Now's when we need pics of the pump imp., the housing showing the seal on top, the wear plate and cup on the pump.
Is the seal on the top of the pump still on?
Then pics of where the exhaust is coming from.

​When the lowers off: does the water tube come out?