Prop size

[SweeperForce]

Hello,
I am going this weekend to look at a boat and test run the motor. The seller don't have a hose so I'm buying a sterilite container and filling it with water. What are the measurments of the lower end for a 1989 150 hp Force outboard? Will a 25 gallon measuring 24"L x 18W x 17"H work? I don't plan on putting it in gear. I know the gentleman selling the boat and I trust him, but still I want to hear the engine run.

Thanks,
Tom

 

[pnwboat]

Re: Prop size

Depends on what type of lower unit it has. If the water pickup vents are located on the lower rounded cylindrical "bullet" part of the gear case housing, it should work. You may not be able to submerge it so the cavitation plate is under water, but it should be OK for testing. Measurement from the front tip of the gear case to the back end of the propeller is about 21". From the bottom of the skeg to the cavitation plate is about 17".

If it is the later style lower unit which have the pick up vents higher up just under the cavitation plate, it may be a little iffy. I don't have measurements on that type of gear case, but I would think it would be similar to the earlier style.

 

[steelespike]

Re: Prop size

Not nearly deep enough.
You need something like a trash barrel. I use a 32 gal for my 50 merc.
Opening is 21" and 27" deep.
You'll surely need something bigger.I like to get the water right up to the mounting bracket to be sure the pump can circulate the water.
If it runs dry you'll cook the pump.I think the key demension is the length of the anti vent plate (just above the prop) front to back.Perhaps the seller can get you the demension.You may need to siphon out some water when your through.
Without a hose how will you fill the barrel?If using a bucket you may need to have one handy to add water without interupting the test.

 

[pnwboat]

Re: Prop size

To get the whole lower unit with cavitation plate plate submerged, you need at least a 28" opening.

 

[SweeperForce]

Re: Prop size

Thanks for all the help, but I think I'm going to put a sub pump with a hose attachment in the tub of water and use prop muffs. It will be louder but safer.

Tom

 

[john from md]

Re: Prop size

I have the same lower and have found that the only container that worked was the big brownish colored one sold for storage at K Mart. It is a two piece with a cover that they market for storing clothes. It has several air holes in it that I filled with RTV and that allows the water level to go up high enough to run without muffs. Once a month I use this method instead of muffs to circulate a salt remover through the engine. The warm water and salt remover seem to do a good job as I pulled my head this year and didn't have nearly the build up I have had in past years.

John