New engine break-in questions

[My4winnsLost]

I just rebuilt my GM 3.0 4 banger. It's an OMC model with a Cobra outdrive. I've rebuilt plenty of engines for cars and trucks, but never a boat. So my questions is what's the proper break-in procedure?

 

[Scaaty]

Re: New engine break-in questions

Just do it same as any other engine, in other words, the worse thing is WOT with 6 people in the boat.........

 

[waterone1@aol.com]

Re: New engine break-in questions

Run the engine at varying throttle settings, without staying at any position for very long. As you get over 10 hours, do some short full throttle runs. Constantly check oil pressure, level and engine temps. Do not idle or run at full throttle for very long. After 20 hours, change oil and filter, consider it broke in.

 

[Jilly - 5]

Re: New engine break-in questions

Yes, take it easy on the new engine, as above. But, do not break in with synthetic oil. Synthetic is too "slippery". Use natural oil, so rings/cylinder walls hone themselves to each other properly. After break-in (I recommend 40 - 50 hours for break-in), then you could switch to synthetic.