johnson gt 175 - no water flow to heads

[blomqvistjs]

long story short
new impeller
new headgasket and deflectors in cylinderblocks
new tstats


everything oem from bombardier.


engine still runs hot and without tstat covers i can tell its dry

how does the water flow from impeller up to heads?

[BarryStrawn]

Water is pumped up a tube into the midsection adapter and from there to the rear exhaust cover between the cylinder heads. There should be a fitting for a pressure gauge on that exhaust cover. Then flows into the block, up one side of each cylinder bank and down the other. That's why the rubber diverters are in there. Then out the bottom of the each cylinder bank into that head. Up the head to the thermostat and poppet and then drains down the outer part of the heads under the covers into the midsection. You should have pressure at the thermostat cover.


Try to find a factory service manual. It will help.

[flabum1017]

It is possible an impeller broke apart at one time and it's pieces worked their way up the water tube and are blocking the water flow

[blomqvistjs]

heads are clean when water hoze is attached to water pipe it comes out of thousing. can i have messed somthing up when i replaced the impeller last time. took down the lower unit again and i cant find anything thats wrong....

can the waterpipe have been out of the pumphousing? how tight should the seal between pumphousing and pipe be? is it smaller in one end and bigger in the other?

[flabum1017]

are you sure the key stayed in place when you put the impeller in place?

[perfmarine1]

Check the length of the water tube. I have seen,if someone misses the water tube in the pump it will bend the watertube and be too short. Do some measurements on tube to pump housing.Always put some grease on the end of watertube so it can slide in the rubber grommet and not curl it.