Johnson FD-20 not pumping water

[wvyen]

Hello,

I just replaced my lower unit on my Johnson FD-20. I had some issues getting the cooling tube lined up; when I was lining it up I pushed the gasket up in the hole. I finall got it out with some damage, I finaly got it on and in place. Once I completed everything I fired it up this afternoon and it's not pumping water... Could this be an issue with the tube and gasket I messed up or is it the water pump? What should I do?

Thanks in advance!

Benny

 

[Daviet]

Re: Johnson FD-20 not pumping water

What gasket are you talking about, do you mean the grommet around the water tube? The grommet is the seal between the water tube and the pump housing and needs to be in good shape. Are you sure the impeller key is in place?

 

[wvyen]

Re: Johnson FD-20 not pumping water

Yes, I guess I would be referring to the grommet around the top of the water tube... No idea about the impeller key

 

[Daviet]

Re: Johnson FD-20 not pumping water

I would drop the lower unit and check the impeller drive key to make sure the impeller is turning and pumping water.

 

[wvyen]

Re: Johnson FD-20 not pumping water

How would I tell if the impeller is turning and pumping water?

 

[HighTrim]

Re: Johnson FD-20 not pumping water

Sounds like you had the water line installed in the impeller housing and were trying to line it up in the upper grommet? If so, near impossible to do, especially alone!

Install the water line first up into the upper grommet, then just worry about lining it up with the grommet in the impeller housing. A little grease will aid in sliding it in. It is common for the water line to get pinched in the grommet, restricting flow.

 

[kfa4303]

Re: Johnson FD-20 not pumping water

+1. I have a '66 20 hp myself. This link may help.

http://www.leeroysramblings.com/johnson_E-FD_15_18hp.html

 

[oldman570]

Re: Johnson FD-20 not pumping water

I would drop the LU and check the impeller key and make sure the impeller is installed with the vanes going in the right direction. The reinstall the LU and water tube and groumets as Hight Trim stated. If running in a barrel always have the water 4" to 6" above the cavation plate so the impeller will prime easy. If the water is not above the water pump of the motor it will not prime as it should. JMO
Oldman570

 

[wvyen]

Re: Johnson FD-20 not pumping water

Ok guys first of all THANKS for all the info!

I think I had a breakthrough, it is definitely pumping water, but I'm not sure it is doing it correctly.

Is this pumping water correctly? As you can see it is coming out of the exhaust as it should, but is also pumping out of the small portside hole in the shaft? Check out this video.

http://m.youtube.com/watch?feature=plcp&v=WNOV-9Mxkak

 

[milliesdad]

Re: Johnson FD-20 not pumping water

I would drop the LU and check the impeller key and make sure the impeller is installed with the vanes going in the right direction. The reinstall the LU and water tube and groumets as Hight Trim stated. If running in a barrel always have the water 4" to 6" above the cavation plate so the impeller will prime easy. If the water is not above the water pump of the motor it will not prime as it should. JMO
Oldman570

I've had 18,20 and 25 HP variations of this and have worked on every one, 1 built from spare parts.

What they oldmaan and hightrim said.

 

[HighTrim]

Re: Johnson FD-20 not pumping water

I cant seem to get the video to work?

 

[wvyen]

Re: Johnson FD-20 not pumping water

ok, try this one...

http://www.youtube.com/watch?v=WNOV-9Mxkak&feature=plcp

 

[kfa4303]

Re: Johnson FD-20 not pumping water

Hi wvyen. That looks good, but fill the water a couple inches higher and it will be even better. The waterline should be about and inch, or two below the main exhaust port. Don't be alarmed if the water in the test tank gets cloudy, poily, funky that's normal.


btw, I just added a tell tale (aka "pee stream") to my '66 20 hp to make checking the waterflow easier. No more craning around to the back of the motor check. It was a pretty easy job and only cost about $5 once I had all the bits together. Here's a link if you're interested. I've also added a DIY PVC Tiller extender, DIY PVC gear shift lever, push button lanyard kill switch (A MUST HAVE SAFETY ITEM) and transom raiser/jackplate. All these little mods make operating the motor a breeze. Don't know how/why I ever lived without them.

http://forums.iboats.com/showthread.php?t=558895

http://forums.iboats.com/showthread.php?t=571848