I've got a 1997 Caravelle 1900BR with a Volvo Penta 3.0L 4 cylinder. The first outing on the boat it blew a circulation hose (runs from thermostat housing to circulating pump on block). The hose blew when I turned the engine off. Everyone told me that I had excess exhaust pressure. So I changed the thermostat, cleaned the riser, blew through the manifold. I let the engine run today for approx. thirty minutes at diff. rpms, periodically checking the hoses. The circulating hose for sure had pressure on it, I could squeeze in on it, but the hose would only compress approx. 1/4 in. The hose running from the thermostat housing to the riser had about the same compression, this line is very rigid though and is hard to squeeze together with the engine shut-off. The small L-shaped line that runs from the therm. housing to the manifold has no pressure at all on it, I could compress it all the way together. When I turn the engine off, immediately all the hoses are easy to squeeze together, have no pressure on them.
My question is, is this normal? Does this sound about right?
Also at idle the majority of water dumps out between transom and unit, a small stream runs out of the exhaust ports (directly above lower unit). Is this also correct? Should no water come out of the prop?
Thanks in Advance.How much pressure should these hoses have on them?The pressure you are talking about is normal. What you should be watching is the temp. And also the oil pressure. You said that you ran the motor at diff rpms but did you put in the water? Flush muffs will cause the motor to act a little different than it will in the water. Go out easy and watch your gauges. Bring it in a little at a time.
