How far into a tub do I need to put the motor in order to test run it?

adt2

Petty Officer 2nd Class
Joined
May 3, 2012
Messages
185
Hiya,

Finally getting around to test-starting my 1957 Johnson 35HP that I picked up a couple of weeks ago. I have it on a stand with the lower unit in a trash can full of water. Got the motor started (took a while, but it eventually fired and ran), but after a minute or so there was no water being spit out the back, so I shut it down.

Just want to make sure I'm not screwing something up. The top of the tub (and, hence, the water) is just below the "fin" on the lower unit; the prop is totally submerged. How deep do I need to sink this thing? And shouldn't water be spitting out the back side? What else do I need to look for while I'm messing with this?

Thanks in advance for the help.
 

kfa4303

Banned
Joined
Sep 17, 2010
Messages
6,094
Re: How far into a tub do I need to put the motor in order to test run it?

HI adt2. That's not deep enough. You want the entire lower unit submerged in water up to about and inch or so below the main exhaust port. You'll probably have to use an old trash can or 55 gal. drum for that big 'ol 35 hp. Here are some vids of motors like yours running in tanks to give you some idea of what to expect. Don't worry if the water is coudy/oily afterwards. That's normal and will go away on the open water.

http://www.youtube.com/watch?v=i6E7P_Hjyps

http://www.youtube.com/watch?v=tYuaEtIUpmI&feature=related

http://www.youtube.com/watch?v=9HuoXFLKA88
 

trojo

Cadet
Joined
May 8, 2012
Messages
11
Re: How far into a tub do I need to put the motor in order to test run it?

Yes you want to make sure the water pump is under the water line.I made this mistake,wont happen again.
 

adt2

Petty Officer 2nd Class
Joined
May 3, 2012
Messages
185
Re: How far into a tub do I need to put the motor in order to test run it?

Awesome...all I have to do now is figure out which part is the water pump...:) Actually, I jury-rigged my tub setup to raise it up, and now everything is groovy. Motor is spitting out warm water from the back side. It is, in fact, cloudy, but per the message above I'm not worried about it. Smokes a bit, but I'm writing that off to the 24:1 oil mixture. That's a LOT of oil.
 
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