IS THE IMPELLER IN THE PROP

[DAVID BRUCE]

Hi,<br />I have been given a Johnson 4 hp motor.<br />It starts and runs then seizes. Very hot. After air cooling it starts again. water cooling problem? I have taken off the prop and found what I think may be the cooling impeller. Can anybody tell me about this motor reg. no. 4.BR.73C SERIES B44866 Thanks

 

[Walker]

Re: IS THE IMPELLER IN THE PROP

Nope. The impellor sit on top of the lower unit. You have to drop the L/U and you will see the water pump housing. The drive shaft goes through it. Take a couple of bolts out of it and pull the housing up off the driveshaft.

 

[DAVID BRUCE]

Re: IS THE IMPELLER IN THE PROP

Thank you Walker sir,<br />I am not sure what you mean.<br />Is the L/U the part below the cavitation plate?<br />If so it is held by 2 bolts.

 

[imstillatwork]

Re: IS THE IMPELLER IN THE PROP

The lower unit is tha section that holds the prop shaft and gears / gear oil.

 

[imstillatwork]

Re: IS THE IMPELLER IN THE PROP

So the impeller is on the vertical drive shaft in the lower unit.

 

[Walker]

Re: IS THE IMPELLER IN THE PROP

Yes sir. But its on the lower unit not in it.

 

[bubbakat]

Re: IS THE IMPELLER IN THE PROP

should look something like this impeller placement

 

[imstillatwork]

Re: IS THE IMPELLER IN THE PROP

Yes sir. But its on the lower unit not in it.

Ahhh yes... I knew that. It is indeed in the mid section, but attached to the lower unit.

 

[DAVID BRUCE]

Re: IS THE IMPELLER IN THE PROP

Thanks Bubbakat for the diagram. What I'm trying to find out is the placement of the pump in laymans terms. Is it just below the motor or further down. Do I have to dismantle the motor?<br />I know I must seem a real dumbo- but I don't want to ruin the damn thing.<br />Also can anybody tell me the year of this engine 4.BR.73C

 

[Chinewalker]

Re: IS THE IMPELLER IN THE PROP

Hi Brucy,<br /> Approximately 10-inches up from the very bottom of the lower unit there will be a bulge with a seam in it. This seam runs horizontally. Below the bulge and seam there will be FOUR bolts that hold the lower unit to the exhaust housing (incorporates the clamp brackets, too.). Remove those four bolts to access the waterpump area. You really should head to a library (bibliotheque?) and see if they have a service manual that covers your motor.<br /> Your motor is a Belgian-made, Right angle drive, 1973 model year...<br />Regards,<br />- Scott

 

[DAVID BRUCE]

Re: IS THE IMPELLER IN THE PROP

Thanx Scott,<br />I will certainly go looking for a service manual.<br />The bulge below the exhaust exits (2) has a seam running aroud it and is held on by 2 bolts. If the water pump is inside bingo and thanhs again.<br />-David.