johnson rkl24 40 hp water flow questions

[todd281]

I have a Johnson 40 HP Rkl24 made in 1962, I am having some issues with the cooling system , When I remove the thermostat housing cover, the thermostat, the holder that it sits in, and the little check type valve that is inside that housing. Then put a set of muffs on it and turn the water on , no water comes out of the head.I left the thermostat housing open and ran the motor for a few seconds, nothing, I have removed the lower end and replaced the impeller ,rechecked it to see that I had installed it correctly , woodruff key in place, fins bent the right way. checked the water tubes, nothing seems to be amiss . I have not replaced the grommets at the top of the water tubes where they enter the powerhead [I think] only because I can not find that part listed and I`m not sure they can be replaced. Maybe I am wrong in assuming that there should be water at the thermostat on startup ? Any ideas or guidance would be appreciated . Happy 4th to all.

 

[oldboat1]

may need to check once more to make sure l.u. assembly is correct -- grommets in impeller housing cap, water tubes in the grommets -- and the correct tube in the correct spot. (Thinking the port tube goes up to engine, starboard circulates down from powerhead.) If you pull it apart again, try rigging a fitting for a hose, and push water up to the powerhead. (Believe there should also be a large o-ring in place on top of the impeller housing.) There is a bypass built into the t.stat housing to allow water to pass whether the stat is open or not -- allows water to circulate during warm-up (i.e., always water circulating). Longshaft would/should have 5" longer tubes.