I finally got moved yesterday from a landlocked lake to the river. I feel like I broke the chains. Anyway, we launched the 3607 yesterday mid-day and I went upstream 3 miles to a transient dock to tie up for the night. This morning, I locked through the dam and made what was about a 45 mile trip downstream to my final destination. The only problems I encountered were the port engine developed a miss after 40+/- miles and the starboard engine heated up a little. If I held the rpm's to about 22-2300, the temp gauge hovered @ 160. All of this brings me to my question... Q: How fast is a 3607 supposed to run at 2,000, 3,000, and 4,000 rpms? What is redline for a 454 crusader engine? For me, 22-2300 produced about 10 mph as read on my gps.
My 1990 Carver 3607 runs 10.1 mph by GPS at 2250 rpm. My mercruiser 454's have only 500 hours on them and at this speed hold a temp of about 160 degree and oil pressure of 60+.
FWC 160 to 180. Raw WC 140 to 160. Raw water temp could also help keeping the temp down. At 2200 to 2500 rpm, you're not making much power or heat, With the typical LBC bypass, you just may not be coming up to temp.
I think redline or prop speed is 42-4400 rpm. It should be able to reach the rated rpm to let you know if the props are the correct size. Obviously you want a clean bottom and wheels before you run it up to full throttle. If they are not fuel injected, anytime you can keep the rpm's below 2800 it will not be running on all 4 barrels and will use substantially less fuel