QD19 Overheat Question – Update

[chris-p]

I find the orings are almost ALWAYS dry rotted and cracking if original for the shift handle. I change them on all my motor restorations now.

[pappy]

How about just drilling the water tube………………
The flow will be much faster there and will, therefore, keep the hole clean of debris. Aim it where you want it and at the height you need it. Don’t like where it is? Solder it up and drill another one.
Some later model engines had holes like this to keep the tuners cool.

[beerman57]

Well, the hole is drilled, incoming water just below the P/H. I tested it, but I wonder how much pressure there will under running conditions. If there is enough pressure it should actually hit the starboard side of the upper mid where it’s getting discolored. How much difference do you think it will make to the exhaust temp in the mid?

[jeff-register]

Robert,
After everything you have been thru with this motor I hope it all works out for you

[fleetwin]

I ran my 58 Sportwin yesterday, it was a hazy day in the 60s so hot ambient temps were not an issue. I’m sure this engine probably has the short exhaust housing divider like yours, but don’t know for sure.
In any event, the top part of the exhaust housing did heat up quite a bit. Sorry, did not have a heat gun with me. You could only hold you finger on the housing for a few seconds, splashing water outside the housing would produce a little steam. But, my shift handle was not hot at all.
So, I’m thinking most of what you are experiencing is somewhat "normal" for these engines, and the hot shift handle can be explained by Art’s loose/sloppy shift shaft/exhaust blow by theory.
Will be interested to hear if the drilled water passage resolves this for you.

[jeff-register]

Pappy,
have you ever drilled out a waterline like this before? I think it’s a great idea. All of my Mercury motors have a tiny hole drilled in the waterline pipe but it was I.D.ed as a drain for the powerhead after it was turned off.
Robert, I think Pappy has a great idea. Best I have read so far!!
Jeff

[Mumbles]

The copper tube in this motor is only about 6" long and runs from the pump to a grommet in the lower part of the housing. The rest of the water tube up to the powerhead is a cavity cast into the exhaust housing so drilling a hole in the copper tube wouldn’t have any bearing on cooling the upper part of the exhaust housing. It would have to be drilled in the cavity where previously indicated to help cool the upper casting.

[pappy]

Oh well……….just a thought.

[beerman57]

I want to thank everyone again for helping with this.
Fleetwin, I bet the water up there is a LOT colder than the mid 80 degree water down here. Maybe this is normal for this model, but how many QD19’s has anyone ever seen with a discolored midsection? My ’62’ ten hp has the same short divider, should I drill a hole in it too?
I’ll let you know how the QD does, probably Monday or Tuesday.

[handyandy]

Just an FYI- the bulletins listed on FiberGlassics are not viewable, I just put a list there for reference. I have a bunch scanned from the 1960’s to early 1970’s and am waiting for the AOMCI Library to expand.

[Author]

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