How to test drive a bare engine

[WNYPCRepair 1,875]

I received the new Onan engine today, and I would like to test drive it before too much time passes. I was considering moving it over beside my 520H, connecting the fuel line and 9 pin, and just run it for a minute sitting on the ground. Then I thought maybe it has too much torque and needs to be bolted down so it doesn't trash around.  :)

 

Any advice on how to test it?

[oldredrider 2,547]

Yeah, you're gonna want to bolt that sucker down!
There was a thread a while back in "engines" regarding bench testing an Onan. Do a search and it will show up.

[bmsgaffer 2,043]

Personally, if I had gotten a NOS onan, I would unbolt the pan and both heads to visually inspect it. Don't run it until you have to.

There will be fuel sitting in the carb and oil getting old sitting in the pan (yes oil breaks down with just time and no use). I would open it up, spray it all with a light oil, close it up wrap it up and put it in climate controlled storage until you decide to use it. Have a set of new gaskets on hand and open it up one more time before you use it and check it all over for surface rust then throw your new gaskets on, torque the bolts, fill'er up and go! You can run through the proper break in period without a huge amount of time passing.

I have no scientific evidence for this, just my thoughts.

[WNYPCRepair 1,875]

I plan on swapping it with the one in my 520 when I get some time and setting the old one up as a spare. I just wanted to test it now before too much time has passed since buying it.

[boovuc 1,090]

You can bring it to my house and I'll test it for a few years!  OK maybe not!
I tested two Onans on my work bench after decarboning them and discovering a valve issue on one. You will see it's quite easy to do. (As stated above, search for the thread on bench testing an Onan).
The hard part was keeping it on the bench and all I did was use C-clamps on the oil sump bolts holes using thick rubber gasketing between the clamp and the aluminum. (You don't want to tighten them down too tight or those tabs will snap). Make sure its a solid surface beneath the tabs. Some flat stock under them will make sure you don't stress them.
I just clamped the two of the four hole tabs that faced me on the bench  leaving the two in the back open. (PTO side facing me). It held it very well. I used a small oil reservoir, (holds a pint), to keep gasoline to the fuel pump.

[WNYPCRepair 1,875]

Thanks for the advice, and I found the topic, I'll check it out now
 

[bmsgaffer 2,043]

Sent you a PM!

[WNYPCRepair 1,875]

Thanks again, added oil, there was none in it to speak of, probably just enough to keep it from rusting. As soon as it pumped some fuel up, it fired up. Ran it for a few seconds and shut it down.