QD19 running a little hot?

[fleetwin]

You ran the engine with the gearcase off, and a hose attached to the water tube? If so, the engine ran cool that way at low speeds?
I guess I would have a closer look at the pump, perhaps the impeller plate isn’t sealing onto the gearcase housing well. Do you have the impeller housing spacer/orings in place? Impeller housing grooved/corroded? Impeller housing air bleed clear? What brand of impeller did you use?

[beerman57]

So I took it out again to finish breaking it in the other day. Now is this normal for this model, because it runs great and got 19.8mph with a power prop on my 13′ Feathercraft – at idle (slow or fast), even the shift handle gets very warm. Then I take it up on plane and when I return to idle speeds the shift lever has cooled off, but when the boat comes off plane and water splashes on the midsection, it makes steam. The motor pumps plenty of water and the water isn’t overly hot. I’m starting to think these things might just be normal?

[chris-p]

No the midsection should not get that hot.

Could you have been sent the wrong base gasket?

The spent cooling water should keep the mid section fairly cool.

[beerman57]

Chris, that’s a $64,000 question! The gasket looked right, I’m trying to picture where the exhaust might be going that’s wrong. At least if I have to pull the P/H again, it’s just a 10hp. I think I’ll run it again, this time with the cowl off and check the cyl. head temp while running. I don’t know, I’ve got 9 hours on it now and it’s never sneezed once or done anything else, except run great and show plenty of water.

[fleetwin]

How warm/hot was it out when you ran the engine? These engines can appear to get pretty hot when outdoor temps warm up in the summer. I’m assuming you have the impeller housing/driveshaft tube/orings in place.
I know guys have mentioned that there are little drain hole(s) inside the exhaust housing that provide an exhaust reiief into the water outlet hole. Sometimes these relief holes get plugged with carbon. Perhaps these relief holes allow a little extra water down into the exhaust housing to keep it cool as well. I admit that I have never really taken the time to notice these relief holes, but be sure to investigate if you remove the powerhead.

[beerman57]

There are 2 "drain" holes in the front of the midsection – right at the top of the lower midsection mount and about even with the bottom of the shift connector cover. They are not plugged up, I’ve noticed water coming out of them. It’s warm here in Fla. – upper 80’s with water temp in the low 80’s. I do have that short tube with Orings in place between the impeller housing and midsection.

[beerman57]

I ran it on a hose with my home made flushing attachment, plenty of water flow and not too hot, cyl. head not hot, midsection was too hot to touch for more than a couple seconds.

UH-OH, I’m also rebuilding a 1962 ten HP and the P/H base gasket I haven’t used yet appears to be for a ’58’. The ’62’ base gasket doesn’t have the 1” x 1/2” opening near the middle and along one side – the ’58’ does!!!!!!!!!!!!

[beerman57]

Now I’m REALLY stumped – it’s got the right base gasket. I guess I’ll rig up something to simulate water going into the block and see how much comes out where. One thing I’ve noticed – not much, if any water and exhaust seems to come out the snout at the back & under the cav. plate – and that’s the water that would cool the midsection and shift mechanism. I just don’t know – the impeller, wear plate & housing are all good. If the powerhead isn’t overheating, why would the midsection?
To H with it, I’m going to the jetty and have a couple cold ones, it’s as hot as August here today.

[1946zephyr]

If you have the powerhead off, I would check the water tube connections in the mid section. I have found a couple over the years that plugged in there from corrosion. It might be necessary to pull the head and make sure the water jackets are free of debris. If a bad impeller in the past has sent a chunk up there, that could easily cause an obstruction.

[beerman57]

OK, I checked about everything today – rigged some hoses and reverse flushed the P/H, but the P/H wasn’t getting hot anyway. Disassembled the water pump again, gasket under the pump seal plate not leaking, pump looks great, but the problem is after the P/H. Held a finger on the bottom of the water tube and poured some water in (with P/H off) no leakage. I’m just totally stumped, can’t find ANYTHING wrong with the water flow, but at idle the shift handle gets hot but cools down after running on a plane, but water steams on the midsection when coming off plane. Checked spark plugs and they are nice and dark, no sign of running hot.

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