QD19 running a little hot?

[chris-p]

Im not sure why that plate, number 2 in the marine engine diagram you posted, is removable>?

The spent cooling water exits from the small hole just aft of that, then out through the snout.

That plate really just keeps the exhaust from coming back up, and forcing it out the snout with the spent cooling water. If you remove that plate, you will see a bypass hole, which leads back down into the gearcase cavity. That hole is where the exhaust gas makes its way out into through the snout on the leg.

I have no idea why that shift handle gets hot to tell you the truth. Nor why your leg is getting so hot. If a ton of cooling water is exiting the snout, that should cool the rear portion of the leg.

[jeff-register]

Chris,
Thank you so much for your input. Does the QD-19 have a T-stat? I’m thinking it needs to be checked. What will happen if a guy leaves the plate off & runs it? Yes the plates comes off. It may be overheating recirculating hot gasses? Thoughts?

[chris-p]

No Jeff no t stat on that model.

[beerman57]

All the water exits midway down the mid, at the "telltail". What I call the snout, at the bottom, rear of the cav. plate is where the exhaust goes. I have to look at something, which means pulling the P/H again. I think my base gasket is right, at least it’s right for the bottom of the block. But all the other P/H base gaskets I have don’t fit the incoming water opening on the mid. But that would cause the P/H to be hot from a lack of water and should cool the exhaust from the leaking water. Really, I’m pretty sure the base gasket is right, it has the circle at the front for the driveshaft. What’s bothering me now is that none of the other base gaskets I have seal off the incoming water from the mid to the P/H – the opening on the gasket isn’t right. But none of those gaskets has the circle at the front for the driveshaft either.

[Mumbles]

Het Beer, what condition is the base gasket in on this motor? There shouldn’t be any fire or exhaust breathing on the shift handle shaft or anywhere in that area. It all goes down the rear exit area as does the cooling water. Any hot exhaust in the front chamber indicates a possible exhaust leak as any exhaust or water in the front chamber has to come up from the bottom. I believe water does come up the drive shaft tube though to cool it and bleeds out externally at the top and bottom. Is there a mouse nest in the gearcase where the underwater exhaust comes out? If this motor has been used in salt water, the inner housing could be corroded thru allowing an exhaust leak.

With the shift handle getting hot when the motor is idling on a boat could be caused by back pressure from the water level causing an internal exhaust leak somewhere but if it cools down when the throttle is opened up, there is no back pressure and the exhaust is actually being scavenged out the lower gearcase opening. Something to think about.

Do you have the proper one year only 305324 base gasket for it as the ’59 and later 308385 thermostat motor gaskets have only a small hole in them for the water to enter the motor while the ’58 gasket has a large cutout. The later gasket would probably work though.

In this pic you can see the exhaust outlet at the bottom with the stainless plate in it. The plate directs the bulk of the exhaust out the bottom but allows a small amount to exit thru the idle relief port along with the cooling water. Check to make sure that all of the small passages for the idle relief system aren’t plugged. Your motor might have some small holes drilled thru under the plate. The water outlet is the large hole at the very bottom of the pic.

Here’s the ’58 QD 19 base gasket

and the ’59 and later and ’57 and earlier base gaskets.

[beerman57]

So I do have the right gasket and it’s new. OK, I went into "paint" on my computer and supposedly reduced this pic to 50% so maybe I can post it here – let’s see what happens……..boy that figures, how do you add an image from your computer?

[chris-p]

I use photobucket

[beerman57]

Do you "copy & paste" it. I’ll try that!
I GIVE UP ON POSTING PICS!!

[jeff-register]

Mumbles,
That was my gut feeling that something is clogged & spent water is not going down the leg to cool the gasses. What is missing in the top of the photo where the driveshaft area is, another plate?

[beerman57]

Yes, another plate in the round cavity. The shift linkage just below that.
I guess I need to pull the P/H, but I’m sure that passage isn’t clogged. HOW could the shift handle cool down from being up on plane, if anything it should get even hotter.

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