Trolling questions

[furball]

I've finally had a couple of days to go trolling in the bay and I have a few observations and questions for those of you with Albin trolling experience.
Observations;
With the trans in gear, I'm trolling at 3.0 - 3.2 knots on GPS and 675-685 rpms. It doesn't take long for engine temp to drops to 140 - 150 degrees. Oil pressure gauge reads about 30. I will often increase rpm's to 725, neutral idle, because I think I read somewhere that you shouldn't idle below 725 for long periods.
Questions;
Do I need to keep rpms at 725? Is an engine temp of 140-150 a problem? I have thought of installing a trolling valve as I would like to troll as slow as 1.5 to 2 knots. If I have a trolling valve installed, can I still increase rpms slightly to 725?
Thanks,
John

[Pitou]

With my engine and tranny set-up I pushed 6 kts. at idle (600 rpm/Cummins) with no wind or current and installed a valve for the '07 season. The results are 1.2 - 2 kts. at idle and the ability to feather in a trolling speed for the targeted fish.

The tranny manufacturer will dictate the max RPM you can push with a valve engaged. With my ZF I can push up to 1200 RPM / I never exceed 1000. The valve acts to divert transmission fluid from the plates giving less lubrication resulting in slight slipage. With excessive RPM's one would burn a tranny if you were to exceed the max RPM or shifted the tranny with the valve engaged. Those are the two taboos. Electronic controls verses mechanical would take the error out of course unless the electronic controls fail. $ 4000.00 more for electronic controls and electronic valve. I went mechanical and pay attention.

I do not believe a lower temp is a problem.