what can I get to clean out the cooling system on my 65hp johnson? Think the passages may be partially clogged cause it is starting to heat up.
What year is the motor?
If your motor is of similar age as mine, maybe this will help.
I run a 1995 88hp Johnson that has two thermostats in a housing on the rear of the power head. Take two bolts out of a cover and they come out. Annoyingly, the thermostats corrode in a year or two and can stick shut causing over heating. Last time the overheat alarm went off, I just removed them. So, the motor is running with full cooling flow all the time. I put a little hotter plugs in to try to avoid plug fouling from running cool and she works very nicely. Over the past two years, she’s run very well and I have no worries about the thermostats stranding me.
'Reminds me… time for new plugs.
17’ Henry O Hornet
26’ Palmer Scott
It is a 1972,have pulled thermostat and it still heats up weather on the hose or in a barrel. Ran water from the bottom with a hose straight through the water pipewith thermostat out and with pressure plugs out. Water pump impeller is in great shape, just doesn’t seem to have enough flow. Heard there was something I could put in passages to help break up any build up and flush out passages but not sure what it is.
Check your water pressure, a blockage should show up as high pressure provided its not on the suction side. I would thing you have a pressure regulator or poppet valve on the bottom of the powerhead somewhere that can cause problems as well.
I can get water through it but it doesn’t seem to be enough. Had lower unit off and stuck water hose to pipe leading to engine. Got a good stream from pressure plug holes and from thermostat hole. Gonna pull cover off to see if temp sensors are caked over. It’s a strong runnin motor but I don’t have the money to buy a lot of stuff. If I get this thing straightened out it won’t sit more than a week without atleast being cranked on a hose. Don’t need this crapola again.
you may have to remove the head, clean out the passages, and install new head gasket.
your motor is pretty easy to work on, and parts shouldnt be a problem.
I would try salt away first, its fairly cheap, and alot easier than a head gasket
I’m now at www.teamcharlestonmarine.com
quote:Had to have mine cleaned last year. :dizzy_face: No chemical would do the trick. Just had to pull the water jackets off and clean, clean, clean. Had my mechanic do the job. Took it off shore immediately after to celebrate and she ran like a champ.. Don't think I would have trusted the motor if I did the job. :wink:
Originally posted by chris Vyou may have to remove the head, clean out the passages, and install new head gasket.
your motor is pretty easy to work on, and parts shouldnt be a problem.
I would try salt away first, its fairly cheap, and alot easier than a head gasketI’m now at www.teamcharlestonmarine.com
Edited to add; On my motor they didn’t have to remove the head(s). Just the water jacket(s). Not sure if yours has them but it might save some work if it does. Good luck.