I know I should post this on the JEGO thread but I'll get more looks here. '58 Johnson rds20. put in new water impeller and a new thermostat but still not getting any cooling water out the exhaust and it runs hot. I pulled the cap off the thermostat and ran the motor and was getting exhaust out the feed hole but no water. Motor ran great but of course I shut it down. Opins?? The pipes from the impeller are all in correctly but wondering also if the connections to the powerhead might be bad. When I blow compressed air through the water inlet hole the air comes out the exhaust. When I blow air through the poppet valve the air comes out somewhere under the shroud.
Even with a blown head gasket it should pump water out of the cyl head with the thermostat cover removed. I've had 'em where they wouldn't pump in the barrel due to excessive aeration but usually when you pull the 'stat cover, you'll get water up to the block & thru the cyl head.
Do you get any drive in Fwd or Reverse? Possible the crankshaft splines could be stripped. Easy to check, pull both plug wires, put the shift in Fwd or Reverse and try to move the prop by hand. It should spin the flywheel and you can try it in both gears.
Check the impeller to make sure it's turning, you may have dropped-out the impeller key while installing the impeller.
Check the water intake screen and intake passages for obstructions, if it gets clogged there, you'll never get water to the pump.
It's also possible when you're installing the L/U, to miss the copper water supply tube into the pump body's water tube grommet. Make sure there's a rubber grommet in the pump body, too.
Last thing, with the >/U removed, blow air and/or flow water up the water supply tube and see if you get circulation.
Always possible to have a blown head gasket so do a compression check.
Is something cracked somewhere that is preventing circulation? I know you said you cleaned out all of the broken rubber of the impeller and cleaned before New was put in. Were you able to find every piece? When I did my fishing motor, I set the impeller on the bench and then took each piece and reassembled like a puzzle. One piece was missing, so I dug around and found it hidden and jammed in the waterway. Maybe air goes through and water might be restricted.
Ed. I shoved a hose up the tubes and got water out of the large hole where the poppet is. I dropped the LU again for the 6th time just to check again. All tubes are installed and fitted right, the rubber grommets are tight. Shifting works I put it in gear while the motor was running before it got too hot. I sunk the LU in a tub of water and spun the drive shaft with a drill and it pumped. I just pulled the cooling cover off and it was bone dry! Something is wrong somewhere. Never worked on a two pipe system before but I traced the tubes to find that the drop pipe on the port side is just blanked off at the impeller, goes nowhere. I'm thinking of swapping out to a single pipe and just plugging the other side.
Does the water flow up from the bottom through the cyl jacket and then out the top? Thinking of putting the LU from my Gale on there. I know that pumped good but it does have the single pipe
That would make sense but the problem is that the second tube dead ends in the impeller housing. I put everything together this AM without the LU. ran a hose up the intake pipe and flushed everything out and water rushed out the second tube opening. I plugged the second tube opening and then water started to circulate through the head like it should. Forcing the water through. My next step is running the motor on idle with a hose directly into the intake and see if it runs cool. If that happens then I will re-install the LU for the 7th time and attach a hose to the intake with a special adaptor I fabricated. I will not give up until I get er done.
O-Kay....Did some more futzin' and here's what I did.
1. Made a new gasket for the upper cooling plate.
2. Ran a hose directly up the shoot and plugged the outlet to flush the system again and find out where the water flows.
3. Installed the cooling cover, devil of a time getting those compression relief springs back in place.
4. Ran the motor and water did flow through the entire system, did not run "cool" but I could keep my hand on the cylinder walls.
5. Re-installed the LU and made sure everything was correct.
6. Put on my handy dandy hose attachment.
7. Started ii up again, water flowed through the pump with the hose, thermostat functioned right.
Before thermostat opened.
You can see the difference in water flow out the exhaust.
The impeller housing showing that that "return" tube is totally blocked off.
One major thing I did find is that the impeller housing was not square on the bottom, had to mill it flush. A clue was probably when I originally pulled the pump apart the PO did not have the shaft seal in place and it was cocked on the driveshaft, Guessing he bent the housing when he put it back together.
Temp outside is now 95deg and humid, time for a cold one. Can't really dunk the motor in the water until next Tuesday. Boat ramp is full of crazies this holiday weekend. Besides my workroom looks like a tornado went through it while doing this dirty work.
Jim, problem solved, thanks.
First time I had to dunk it was today. Bad weather for boaters and fishing so the landing was totally abandoned. Motor started right up but was only firing one cylinder then the second one would kick in occasionally. Not bad considering I didn't touch any ignition stuff. I'm just going to put in some new plugs for now.
Cooling worked as it should. Ran it for about a half hour trying to get the idle dialed in etc. Pretty much close to where it should be, just needs permanent settings. Will have to get someone to run with me to dial in the high and low speed jets, maybe Saturday at the Kosh meeting. 12 gallons of 24:1 gas and ready to go.