Below is a hookup diagram/parts list for the coolant hoses.
I was appalled to see that the impeller on the freshwater pump lost one of its vanes after only 2 years of service. It was a Yanmar part too...
Today I installed two stainless hose clamps around the lower body of the heat exchanger to prevent cracking of the mounting lugs. The heat exchanger came without the clamps unfortunately this time. The old unit had the clamps from the factory 18 years ago.
The raw water pump would not pull seawater through initially until the strainer was primed with water. In past work on the cooling system I don't recall having this issue.
Thermostat Advice for Sendure Kit: I have the yanmar 2GM freshwater conversion(by sendure). One of the advantages to converting to fresh water is being able to run your engine at a higher operating temperature (with the proper thermostat installed) than with sea water cooling (lower temps reduce caulking, mineralization, and corrosion internally from sea water, so use a colder thermostat). The fresh water conversion allows for a higher operating temperature (optimal combustion temps/drier oil), but is only possible if you have the higher temperature thermostat with your aftermarket cooling system. It looks like you already upgraded the alarm temp to the 2gmf alarm, which I did as well, but do you have the proper temp thermostat? The 2GMF higher operating temp thermostat is a larger bore and does not fit into the 2GM thermostat housing, which is different between 2GM and 2GMF. To compensate for the different housing, there was a higher operating temperature thermostat for the sendure conversion that is no longer available since many years (manufactured by Dole I believe). After a truly exhausting search, I was able to locate a suitable thermostat for a Johnson outboard that was intended for use in fresh water (therefore has a higher operating temp and no worry about sea water mineralization). The part # is a JOHNSON EVINRUDE OMC 5031762 THERMOSTAT 72 DEGREES The only modification I made to it, was to drill a small bleeder hole in the valve if you want so it has the same bleed hole as the original thermostat. Did you get a good deal on the replacement heat exchanger? I'm likely to need to replace mine at some point. Thanks for your blog!
ReplyDelete- Jeff
The high temp switch you posted a picture of might not be the right switch as that is a RWC (raw water cooling) system reference number.
ReplyDeleteThe yanmar FWC(fresh water cooling) high temperature switch for the overheat alarm has a green insulator and switches on @ 95 C (203 F). I am showing part # 127610-91350 for that.
There is also an even higher temp 106 C switch for the fresh water systems part# 127610-91360, but the 95C one above was recommended to me.
Good luck with it!
- Jeff