all i want for christmas is my motor to work.

shane56inlet · Dec 3, 2009

OK, i have a 1975 40hp johnson. while replacing the water pump i ran into a couple issues. the driveshaft is stuck in the head but the lower unit came off. i tried hanging it upsidedown and everything. so i came up with another plan i sliced the middle unit in two places so i can slide it around the water pump after i replaced it. while replacing the impeller there was nothing left but the ring and a little plastic. so after i replaced everything i put it back together and it took a min before it pumped water but it did. Then it stopped. i took the lower unit off again and everything was fine. tried it again and it only spit water when it was reving high. so i took it down to the docks praying that it would be fine, when i started it no water pumped i drove in a circle and it still didnt pump so i brought it back in because i didnt want it to overheat and sure enough it wouldnt start up again beacuse it was too hot. now im stuck. please help me this has been a month project that i really need to finish

shane56inlet · Dec 3, 2009

Re: all i want for christmas is my motor to work.

all i can think of is plastic stuck in the housing and i have tried shoving a hose up the housing and water flowed thorugh fine.

bankerjohn · Dec 3, 2009

Re: all i want for christmas is my motor to work.

shane56inlet said:
so i came up with another plan i sliced the middle unit in two places so i can slide it around the water pump after i replaced it.

Not sure I understand what you did regarding "slicing the middle unit" ... but it sounds like maybe you failed to insert the key that connects the impeller to the drive shaft. If that key is left out, the impeller won't turn, and no water will be pumped!

R.Johnson · Dec 3, 2009

Re: all i want for christmas is my motor to work.

This is confusing! What do you mean by driveshaft stuck in the head? If the shaft was stuck up in the crankshaft, or power head, the lower unit would not drop down. The shaft is not supposed to pull out of the gearcase, or lower unit. I can't visualize what you were cutting on. Maybe still to early in the morning.

shane56inlet · Dec 3, 2009

Re: all i want for christmas is my motor to work.

sorry im not too familiar with the termonology but the driveshaft is stuck in the power head. there is a spline on the bottom and supposed to be a spline on the top too but its not coming out. but yes i did put the key way in. and regarding the slice in the middle unit, its a long shaft i think, there is a lower unit, a middle unit that i can remove if i want and the upper part of the motor. since the driveshaft didnt come down i had to cut a section on the middle unit so i could put the keyway in and bolt the water pump down. (i couldnt get to the bolts unless the middle unit was out of the way, so the cut was made to put the unit on after i bolted it.) but the pump works almost spuraticaly, ill rev it and it will pump then i slow it down and it wont work then ill rev it again and it wont work for like 30 secs into almost full rev, sometimes it wont pump and the motor will jus overheat. Im so confused

R.Johnson · Dec 3, 2009

Re: all i want for christmas is my motor to work.

Could you post a picture of this?

shane56inlet · Dec 3, 2009

Re: all i want for christmas is my motor to work.

i tried to post a picture but it wont let me. i can try to send it to an email address.

bankerjohn · Dec 3, 2009

Re: all i want for christmas is my motor to work.

If you're trying to add an "attachment" ... the forum restricts the size of a file to less than 100K. Re-size your pics to < 100K and they should get uploaded as an attachment. Otherwise, you'll need to load your pics to a web site (like Photobucket, etc.) ... and then paste a link to the pic as HTML in your posting.

shane56inlet · Dec 3, 2009

Re: all i want for christmas is my motor to work.

yay i did it

jasper60103 · Dec 3, 2009

Re: all i want for christmas is my motor to work.

I uploaded a diagram of your gearcase for reference. You need to figure out where the blockage is. The water pump has to be primed first. i.e. filled with water. Then water is pumped up the water tube and so on.

edit: the rubber grommet (#2) is usually a prime suspect. It gets pinched by the water tube sometimes when the lower unit is re-attached. Oh, by the way, nice cut on the gearcase extension.

shane56inlet · Dec 3, 2009

Re: all i want for christmas is my motor to work.

well i just ran it in a can and it pumped fine so im gonna take it out again for the 3rd time to see if it pumps out there. ill keep it updated. if anyone knows any other way to clear the blockage up in the motor let me know. thank you. Shane

R.Johnson · Dec 3, 2009

Re: all i want for christmas is my motor to work.

You cut a window in the 5" extension , which was part of the exhaust housing. I keep saying! you can't beat this! I just have to wait a minute.

shane56inlet · Dec 3, 2009

Re: all i want for christmas is my motor to work.

so the 3rd time was a FAILURE!!!! i dont get it.. i dropped it in the water on the trailer stil started it up and it spit fine i put it in reverse and it spit fine then i drove it in a circle and back on the trailer and it stopped spitting in the middle of my circle!!!!! then it wont start back up because its too hot. im going crazy. please someone help me. if it is blockage how can i get rid of it.

tashasdaddy · Dec 3, 2009

Re: all i want for christmas is my motor to work.

thermostat? did you remove it and backwash?

madgadget · Dec 3, 2009

Re: all i want for christmas is my motor to work.

Can you take out the pump and force water through it all backwards to see if it clears anything?

shane56inlet · Dec 3, 2009

Re: all i want for christmas is my motor to work.

well i cant really backwash it because the exhaust holes are right under the spit hole( it dosent pee it spits i think its just the way the motor is) so if i would shove a hose by the spit hole im afraid it will go up the exhaust hole and up in the motor.

shane56inlet · Dec 3, 2009

Re: all i want for christmas is my motor to work.

i have tried to wash it from the bottom up and water comes out but it obviously has something still in there.

R.Johnson · Dec 3, 2009

Re: all i want for christmas is my motor to work.

Look at the photo! Worth a thousand words.

bktheking · Dec 3, 2009

Re: all i want for christmas is my motor to work.

R.Johnson said:
Look at the photo! Worth a thousand words.

Rjohnson, I get ya! Am I missing something, are those two cuts in the lower unit? Don't know if I'd trust that kind of setup, i'm assuming you'd want your lower unit leg to be somewhat rigid, that's like cutting slots in your aluminum ladder!!!! I'd be planning on having that welded up after you get the pump working or a replacement leg. You can check circulation by putting the lower in water and spinning the shaft with a drill, only problem is you don't have a shaft to test with from what I'm reading.

shane56inlet · Dec 3, 2009

Re: all i want for christmas is my motor to work.

i have a shaft, and it runs fine. the pump just wont stay pumping i think there is blockage but i still am not sure how to get rid of the blockage

all i want for christmas is my motor to work.

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