Thanks GT

Sounds like I will be needing to add a gate valve to my system.  I never get over 100.  Water is between 70-75, so I should be idling at about 125. 
This will be helpful.
Thanks

Hells ya! Gate valve that thing!

You will probably have to adjust it to idle about 150°F. It will typically drop to around 120°F or so when on the loud pedal.

Under 100°F is silly scary.

This causes a lot of potential problems,  including cracked valve seats,  piston skirt galling, sweaty oil (valve cover snot), fat fuel ratio and poor performance.

About 120°F is really about as cold as you should go,  unless of course the water is 40°F, but that's crazy talk. Lol


FWIW.

GT

Sounds good, already ordered a stainless steel one from one of my vendors, will be here this afternoon.
Ya none of that sounds like any fun and if the water is 40 I will be in the garage upgrading my boat!! 

This is a topic I know well.
I will make it as simple as possible.
"A brass gate valve is a good choice for throttling fluids. The brass is very resistant to corrosion. The gate valve allows for fine adjustment of flow. less acceptable to vibration. Good choice for throttling fluids.

"A ball valve is not made for throttling fluids. A ball valve is only meant to be in the open or closed  position" with only a 90° turn on the handle you could lose flow very quickly due to a bump vibration or someone accidentally just being too close and bumping it but not realizing. Most of all the ball valve is not intended for throttling fluids. Ball valves are intended to be open or closed.

Be sure not to get a regular outside tap valve. Although you may think they look fairly similar they're not similar in design. Under conditions of high flow the rubber gasket could fold over and close off your flow.