got her runnin but now she won't spit water, impeller is brand new

[jwilkey84]

I got my 72 johnson 20 hp running but now it isn't spitting water out the back of the motor with the exhaust. This motor has no tell tale. It does have a thermostat. impeller is brand new. I took off the lower unit tonight just to make sure everything with the new impeller was correct, and it was. I put my mouth on the water tube and am able to blow air into it. If it were plugged would it let air in? I am afaraid to blow compressed air up the water tube in case there is something in there, I dont want to lodge it any deeper. Is there anyway I can shoot compressed air through the system backwards, on a different motor with a tell tale I shot air from the tell tale back into the system and a hunk of crap shot out the bottom of the water tube. I also shot water with the hose up the water tube, but it was hard to tell where it was all going, but when I did take the hose away water would run out for a few seconds like it was taking the water up the tube. I haven't checked the tstat, but if that were bad wouldn't water still come out the exhaust? Also there is a threaded hole in the top side of the outer exhaust cover, is this for a temp gauge? Where does the water go exactly when it goes up the tube? What do the upper and lower bypass covers do, does water go in there? Sorry, for so many questions in one post, but I appereciate the help.

 

[HighTrim]

Re: got her runnin but now she won't spit water, impeller is brand new

First, a trouble spot is the rubber grommet that the water tube slides in. Are you positive that the rubber is not restricting the water flow? As far as water tube itself goes, I would remove the t stat, then blow compressed air up the water tube, ensuring it exits at the t stat housing, the blow back down backflushing it. Also ensure that the water intake area is free of debris. The key is in the impeller right?

 

[jwilkey84]

Re: got her runnin but now she won't spit water, impeller is brand new

the impeller key is in, and I am 100% sure that the water tube is in the rubber grommet correctly. I just wanted to do everything I could before removing the tstat, to prevent having to get new gaskets and stuff, if it weren't necessary. But am I correct that water should still come out even if the tstat is not functioning, or does that only apply to motors with a tell tale?

 

[HighTrim]

Re: got her runnin but now she won't spit water, impeller is brand new

Was it spitting water before you changed the impeller? Or is this a new motor to you?

 

[F_R]

Re: got her runnin but now she won't spit water, impeller is brand new

Can we assume you have the motor deep enough in the water? The bulge where the water pump is has to be submerged before starting. Yes. water should go through whether the t'stat is open or closed. The upper and lower bypass covers have nothing to do with it and there is no water in there (better not be, anyway).

 

[samo_ott]

Re: got her runnin but now she won't spit water, impeller is brand new

On my 22cu in 18's which are the same as your 20, I test the water pump by taking the LU off and putting it in a bucket of water and then turning the driveshaft with a 1/2" drill. At 330 rpm (my drill speed) my water shoots up about 8-10". If that's good, look elsewhere.

 

[jwilkey84]

Re: got her runnin but now she won't spit water, impeller is brand new

yes I have it deep enough in water. You just put the drill right on the drive shaft, can that hurt the top end of the shaft/splines? I got this motor last summer and got it to start but not run good so I put in away for a winter project. I think it was spitting water last summer, but I am not 100% on that. How hard should the shaft turn when the lower unit is off? It seems kind of hard to turn by hand when the impeller and housing is in place. I kept turning the shaft as I was tightening the screws to ensure the impeller didn't get pinched, but it is pretty stiff. I can barely turn it by hand. I have been using a pair of pliars to grip the shaft to turn it. It doesn't get stiff until the last couple of turns on the screws as in compacts the housing/plate/impeller all together.

 

[F_R]

Re: got her runnin but now she won't spit water, impeller is brand new

Oh-oh, that could be a clue. Maybe the impeller is not to spec (too thick)???

 

[mstrud]

Re: got her runnin but now she won't spit water, impeller is brand new

hows the screen look on the lower unit. My old evi. has quite a few gaps in the screen, on a few occasions i've sucked up lake weeds clogging the line up in the motor itself. the repeated cure... forget compressed air. get a garden hose nozzle. the kind that is just conical with about a quarter inch outlet at the top (maybe less actually). pull off the lower unit and jam the cone up into the water intake tube running down from the top of the midsection housing. let her rip. on mine the flow will only be a few feet (with the motor tilted up) until it blasts clear. in which case the motor will be pissing about 15-20 ft afterwords. hope it helps... Ive needlessly invested time and money on a waterpump rebuild when all i had to do was this simple blasting technique. hope to help.

 

[tashasdaddy]

Re: got her runnin but now she won't spit water, impeller is brand new

make sure the impeller is completely set all the way down, and the key is properly seated. if key is cocked it will bind the impeller, and not go all the way down. put some soapy water on impeller.

 

[jwilkey84]

Re: got her runnin but now she won't spit water, impeller is brand new

i dont think this style of key can get cocked. It is just a small piece of cylindrical metal about the size of a #2 pencil lead and about 1/4" long that slides into the shaft and the impeller slides down over the part that sticks out. The impeller is a tight fit, but I thought it would probably wear a little over time. After I had everything back together, I can pull the start rope and the prop turns, so it isn't like it is EXTREMELY tight.

 

[Benny1963]

Re: got her runnin but now she won't spit water, impeller is brand new

hey man how you doing .recheck your part number .
my motor did the same thing i took it to the river and fired it up
it was fine i will probaly put tell tale. on mine run it on the water and watch temp check your buzzer for overheat
bennyb

 

[Solittle]

Re: got her runnin but now she won't spit water, impeller is brand new

Seems to me that you are troubleshooting for a problem that may not exist. Fire it up and place your fingers on the head. It should get hot but not so hot that you can't touch it for a few seconds. To be even more certain get a couple of temperature stick and verify that it is not overheating.

 

[samo_ott]

Re: got her runnin but now she won't spit water, impeller is brand new

I agree. It might be ok. My driveshafts are quite hard to turn also when I install em.

 

[jwilkey84]

Re: got her runnin but now she won't spit water, impeller is brand new

thanks guys, there is a threaded hole in the top parf of the outer exhaust cover, could that be a place to screw in a temp guage? I will fire it up tomorrow morning and hopefully everything works and water is pumping good, if not i might try taking to tstat out and blowing some air back through the system.

 

[Benny1963]

Re: got her runnin but now she won't spit water, impeller is brand new

as everyone said and as i said had same issues . take it and put it in the water and watch head temp.with sticks or with your hand my motor did same thing .but ran good and cool on the river.give it a shot. are just go ahed and change thermos to be safe ,i just change them so that i know beyond doubt there good and not bad lots of times they just get nasty with age and dont work quite as well.they are not very expensive
benny b