I am down in Cabo for my “final,final” effort to solve the overheat problem in the starboardengine. (See my past 3 posts for the gory details). In reviewingold test data looking for combusion gas leak (not there) I realizedI was not holding coolant pressure over time. So I confirmed thisproblem by running air into the system, and then replaced the fillriser and tightened hoses, and found it now held pressure. This mustbe it. I then tested the boat and it still overheated! I thenchanged two things. I removed the water pump and inspected it andthe gaskets, and used my new bore scope to look in the block. Everything nominal. But I found the suction hose had about 6 incheson the end leaving the heat exchanger where the spring had slidforward. It could be the problem, but the other “good” enginehas the same issue so maybe not. I corrected the misplaced springand then intalled a thermostat that had some extra vent holes drilledin it. Since the left bank did not overheat when flow increasedbecause of no thermostat (see past posts), I wanted to try anincreased flow, but not an uncontrolled flow. It works like a charm(or maybe it was the change to stiffen the suction hose?) In anycase, the engine runs cool (130-140) at low rpms, but warms up to160-170 at anything over 2500 rpm. Pressures look good with none ofthe cavitation boucing around that I got without the thermostat. Shooting the gun at the old “hot spot” where fluid leaves theleft bank shows temps are under control. I think it will run thisway forever.
I know I should take the head off(again) and really look hard now that I have a bore scope, but it isrunning well, sucking back coolant as it should, etc. etc. I AMDONE! Thanks again to everyone that provided advise.
Unfortunately, today the port enginestarted losing power. I will follow with a separate post. Don't youjust love boats?
CaboJohn
I know I should take the head off(again) and really look hard now that I have a bore scope, but it isrunning well, sucking back coolant as it should, etc. etc. I AMDONE! Thanks again to everyone that provided advise.
Unfortunately, today the port enginestarted losing power. I will follow with a separate post. Don't youjust love boats?
CaboJohn
