Running motor without out drive?

Ok I will start with a little back story. I bought a 87 thundercraft with a 3.0 mercruiser and alpha one gen one outdrive. That was about 5 years ago and since I was totally new to boating I made a few rookie mistakes. First off I bought what turned out to be a rotten boat, and to top it off I failed to properly winterize the outdrive:facepalm:. The next spring I noticed the lower gear case was split in half. not having the funds to replace it i decided to rebuild the boat. Long story short 4 years latter boat in pieces (still) and I lost the ambition to do anything with it. A few weeks ago I had had the chance to get a FREE solid boat minus motor and drive I also bought another drive to replace my cracked one. while removing the upper cap on the drive I broke a bolt resulting in the case cracking (just my luck). Ok back to my topic I have my old motor in the new boat and almost all wires/plumbing hooked up. Its been 4 years since i last ran this motor and it ran fine when I winterized it (properly). I would like to know if it will run before I put much more money into a lost cause. Is it possible to run water to the motor without the drive hooked up? I don't want to even try to turn it over without some sort of cooling.

Thank you in advance for any help

Tim.

Re: Running motor without out drive?

You can start it for maybe 1 minute with out water or drive. Don't start it with the drive on and NO water.

Re: Running motor without out drive?

It would be possible to produce a fitting to supply water to the engine with the drive off.
Do Not run the engine without water flowing.
The engine block will be fine for a few minutes but the plastic exhaust lines will not last anywhere near that long.

The first time you start up an engine with a drained block it takes a few seconds for water to make it to the exhaust.
It you just want to know if the engine will start and run, keep the run under 10 seconds and you should be fine.

Sticking a garden hose in the water passage of the Gimbel housing might be a viable RedNeck workaround.

Re: Running motor without out drive?

I Think I like the "redneck work around" Is there anyone else out there that thinks this may work or have used this method before?

Re: Running motor without out drive?

I have ran my 140 on the bench by hooking a cut off garden hose to the water inlet on the t-stat housing ( where the raw water supply hose goes). Worked fine. I agree don't dry run it for more than a few seconds.

Re: Running motor without out drive?

bugzy_1 said:

I have ran my 140 on the bench by hooking a cut off garden hose to the water inlet on the t-stat housing ( where the raw water supply hose goes). Worked fine. I agree don't dry run it for more than a few seconds.

Click to expand...

Running it on the bench is a little different from running it in the boat.
The vast majority of the water is supplied to the exhaust Manifolds/Risers without ever passing through the block.
The Exhaust Manifolds/Risers NEED water very quickly. (10-15 Seconds.)

The block will not "Need" water until it get up to operating temperature. (A few Minutes)
Once up to temperature the thermostat opens to allow only enough water in, to hold the temperature steady.
The block may only need a few quarts each minute at idle.
The exhaust may be moving more than 5 gallons in that same time.

An Auto exhaust is all metal and Operates Red Hot.
A Marine exhaust is made of rubber hoses and plastic fitting and is only bath water warm.
Before starting, be sure the exhaust is getting water. It should initially feel very cold from the water flowing.
If you can't keep you hand on the exhaust manifold, it is too hot.

Re: Running motor without out drive?

I had my outdrive off this spring and I ran my 3.0L engine often with a garden hose hooked up to the 3/4" hose that goes into the top of the thermostat housing. When you turn on the hose, water will start to come out the transom within a few seconds, then start the engine. The hose is simply supplying the water at a similar rate as the sea pump. My hose has a lot of pressure, it feeds off of the 1" main line, so your results may vary.

Re: Running motor without out drive?

I would like to know if it will run before I put much more money into a lost cause. Is it possible to run water to the motor without the drive hooked up? I don't want to even try to turn it over without some sort of cooling.

Click to expand...

Hook up your garden hose to the thermostat housing where the water from the drive normally hooks up.

Simple and easy and you can run it as long as you like.

Re: Running motor without out drive?

Ok Im going with the garden hose. Fingers crossed Hope she fires