Catalina 350 International Association

I think you've isolated your problem correctly. Sounds like there's an obstruction to the raw water intake (plastic bag, grass, barnacles etc). Depending on your preference you could either dive and inspect the opening or you could detach the hose from the thru hull and slide a wooden dowel to try and clear the obstruction. I've also heard of using a dingy air pump as well. Let us know what you find out.

Thanks Ken. I will give that a try!

Check for water flow from thru hull. If restricted: Close thru hull, take off hose connection, attach dinghy inflator foot pump to thru hull, open thru hull and immediately push air quickly through the dinghy inflator. You will hear it clear any lodged debris. Close thru hull remove dinghy foot pump. Open thru hull briefly to check water flow. Repeat if necessary.

Many thanks Ken -

Escape is up and running again! I scraped an amazing amount of marine growth, tiny shells and crap out the thru-hull, hose, and elbow connection to the raw water strainer. I thought there was no problem there because the strainer was clean. It was clean because the intake was almost completely stopped up! Note to self to check that first next time.

Cheers,

Jim McBrayer
s/v Escape
C-350 hull #40
Fort Lauderdale, FL

Turns out my overheating problem was pieces of old pencil zinc tips. when I would throttle up the pieces would block off some of the cooling tubes. Pulled off the end cap and cleaned out the pieces. Temp is back down to 170-175.

It should shoot out rather forcefully 6 or more inches. I was having major overheating. Finally traced it to clogged thruhull, hose and elbow into strainer. Cleaned with various tools and dinghy pump...

A general question, at what temperature should we start to be concerned about engine overheating? What is 'normal' and what is unacceptable? Does anyone know what the set point is for the high temperature alarm?

I normally cruise at around 2200 RPM and temperature gauge stays around 165-170 (as best as I can read the helm gauge). Yesterday I was fighting a tidal current and trying to get home before a thunderstorm and pushed the RPM up to around 2500 and the temperature went up to around 180. Of course I should note this was on the west coast of FL in late July, so the water temperature is almost 90 degrees and these numbers are just what the helm gauge is showing as I don't have an actual heat gun to measure real temperatures anywhere on the engine.

Hi. I replaced my original heat exchanger but after sand-blasting (only the outside!) and painting, it looks like new.

However, I saw that the small tubes have a white coating on their outside (probably calcium carbonate). This can't help with heat transfer and I was wondering if anyone had tried Lime-Away to clean them?

I cleaned the inside of them with ACME TOOL No. 39PP-42-1Z ($230.99). (I can't believe when they put the word "Marine" on a coat hanger the cost goes up so much!)

Thanks in advance.

dave
Nybor 411

You can take your HX to a radiator shop to have it "pickeled" as some call it. I believe they soak the HX in an acid solution (oxalic acid?). Should be clean as a whistle after that. I try to do mine every 2 or 3 years.