motor testing out of the water

[spartanpele]

I have a 1987 Force-85hp. I recently did some tune up and L/U unit work and I want to test the motor before taking it out on the water this weekend.<br /><br />Is there a way to test a motor without it being in the water? <br /><br />I'm thinking of buying a huge tub, filling it with water, and lowering the motor into the tub. What are the risks with testing the motor that way?

 

[Dhadley]

Re: motor testing out of the water

Ya gotta be quick. A prop in gear will empty a tub rather quickly. You can use a test tank but youll need a test wheel.

 

[spartanpele]

Re: motor testing out of the water

Dhadley...thanks for the heads up on using a tub.<br /><br />I'm trying to test not only that the engine will start, but also that the engine will go into gear as well (neutral-fwd, bkwd, etc). <br /><br />Can I use muffs for that?

 

[NMplayer]

Re: motor testing out of the water

Its not reccomended that you use muffs when you want to put it in gear. That being said I have had to break that rule a couple of times because I didn't have anything else. I have only done it for two seconds at the lowest idle just to make sure it would shift. It didn't hurt anything.<br /><br />Again, its not recommended and I'm not telling you its OK to do it. Your only supposed to shift it under load

 

[SeaJayacas]

Re: motor testing out of the water

For testing purposes IMO running it on the rabbit ears, putting it in gear for a limited amount of time, and running it in neutral at moderate (say 2,500) rpms for awhile shouldn't hurt the engine.<br /><br />I have done it with my engine, and if that testing was going to cause the engine to fail, I would rather have it happen on dry land than out in the ocean.<br /><br />Also, I imagine that outboard mechanics do this all the time while working on engines.

 

[spartanpele]

Re: motor testing out of the water

Thanks for the info guys...<br /><br />My whole intent is to test that it will start (the engine hasn't been started in a couple years), and that the gear will engage. If the engine can start and engage, then this Saturday I want to take the boat onto a local lake and open her up to see how she runs.<br /><br />I'll see what I can find for a tub as well... I'm just anxious to hear this thing turnover!

 

[BoatBuoy]

Re: motor testing out of the water

Tub may not be deep enough to cover the water pump. Get a large, plastic trashcan.

 

[Silvertip]

Re: motor testing out of the water

You don't need a tub or tank, just buy a set of muffs and hook it up to a garden hose with the faucet opened only enough to prevent blowing the muffs off the engine. Don't exceed 2500 RPM. A few shifts into and out of gear will not hurt anything. KEEP HANDS, FEET, PETS AND KIDS AWAY FROM THE ENGINE WHILE DOING THIS

 

[Mark42]

Re: motor testing out of the water

I can't see how while running on the garden hose you can possably damage the engine by putting it in gear. If anything there is less stress on the motor when the prop is in air than water. Plus it's easy to see if things are bent or running true. Just don't rev it up and keep everything clear of the prop. <br /><br />If I'm wrong, please explain why so I don't remain ignorant on this topic.

 

[willamettejeff]

Re: motor testing out of the water

The only reason I can see for not wanting to put the motor in gear when on muffs is that the engine idles at higher RPM than when in the water and this results in a greater strain on the gearbox when shifting into gear. Also, due to the lack water loading, the prop tends to rotate faster in the forward direction, as it does even when not in gear, so shifting into reverse puts even a higher strain on the gearbox then shifting into forward.

 

[spartanpele]

Re: motor testing out of the water

Last night I ran the motor with muffs on. <br /><br />I put a small plastic kids pool underneath the motor to catch the water (the boats in my garage), hooked up the muffs with the garden hose, and started her up. I was relieved she started. I then put her in gear and slowly gave enough rpms to see the prop start to go fwd. Then went back to neutral, and then went to reverse and did the same thing, just enough for it to start turning. Once I saw the gearing worked, I put it back in neutral and shut if off.<br /><br />This weekend I plan on taking her out to the lake and will open her up a bit more to see how she runs. Shes been sitting for almost 2 yrs, so I'm relieved she started and would shift. I still need to determine the water pump works under load, and also how the exhaust runs given the exhaust tube gasket is out.<br /><br />But so far, so good...Thank God!<br /><br />Thanks everyone for your help the past two weeks in getting it up and running.

 

[BF]

Re: motor testing out of the water

Hmmm... the prop should be turning as soon as you put it in fwd or reverse, you shouldn't need to put it in fwd and then rev it a bit before the prop starts turning. If you mean to say that you slowly moved the throttle/shift lever just until the gears engaged... well you shouldn't do that. You should shift it smoothly/firmly into fwd or reverse, not slowly shift it. You're just letting the clutch dog bang into the gears for more revolutions before engaging if you do it slowly. (much more wear)<br /><br />As said above, the prop will usually turn even if the engine is in "N"... that's 'cause the forward gear (which is turning anytime the engine is running) swishes the gear oil around in the direction it's turning, and the oil is thick enough to turn the dog/prop shaft, even though they're not mechanically engaged.<br /><br />hopefully it works for you! It's rewarding to bring one of these back to life, isn't it?<br /><br />Brent

 

[Mark42]

Re: motor testing out of the water

Yeah, like BF said about shifting. Someone once told about how to shift an outboard: "Don't ease it in, and don't jam it in either. Just shift it with purpose".<br /><br />The problem and danger with shifting fast and hard is that you can bring the two faces together that do not mesh, and forcing it can bend linkage.