Run In Procedure. Newly rebuilt powerhead

[odyssey aka Blue streak]

Just nearing the finish of what has been a pain stacking 3 year rebuild of my OMC V6... It has had everying short of a new crank and castings. The time has come to flick the key for the first time but i am unsure of the following

How much oil to run for the first couple of hours.

What are the does and dont's of running a completly rebuilt powerhead

Do i run it in with the timing retarded etc etc.

Any help would be appriciated..

For those of you that are going to tell me i shouldn't have bothered rebuilding a 30 year old outboard your probally right.. but i like it so i did.

[Jay Smith]

Looks like you did a great job too......

All I can report is the way I break in V-6 steel sleeved Mercurys.


I NEVER EVER double oil ANY engine, when the engine is first fired it has plenty of extra oil and assembly grease passsing through the engine. I Break in at 32 : 1 with nothing but petrolium oils ( no syn ) Double oiling creates a fuel with a heavier and thicker viscosity and will go through the metering system ( jet or injector ) with the same amount of pfressure slower and thats makes a motor LEAN not RICH. After all what passes through a funnel quicker water or syrup ???

I also use 1 heat range hotter on the plugs to burn this extra oil and grease from the system. for the first tankfull only...Then return to the normal heat range.

I set the timing at what I'm going to normally run at. I use a dial indicator and index all plugs at .150" or 25 degrees and at WOT check for a switch box causing 1 plug to fire advanced , this will then become my constant hole and I will set it at 25 and the rest will be as they will be.

I Idle the engine on the water muffs ( I use and engine stand ) for 1-2 hours closley monerting the head temps with a temp gun.. I then check for leaks after I've set timing and link and sinck...

I then go to the water and run the motor jumping it on plane and then running it 3500 ish for about 1 hour reducing rpm and raising it , at half way point I suggest shutting off engine and letting it cool on the trailor. remove cowling and inspect for any abnormal issues. Next put it back in the water run the rest of the tank out hopefully its will run 30-40 gallons out.


Next time out go to the colder normal plugs run it up this time still at 32:1 to 4500 repeating the same method. Next trip add 1000 rpms BUT never hold it at the top rpm per session always vary up and down..

The last session reduce the oil ratio to 40:1 and use a good blend .....

This method may sound weird to most as most are still into the double oil thing , I urge you to refraine from this, excess oil creates heat something your new motor doesn't need..I have been successfully building race and recrteational engines for 14 years and this has ALWAYS worked for me and my customers..

Good luck and if you have questions don't hesitate to ask ..,
Jay

[odyssey aka Blue streak]

many thanks Jay. Every thing seems to make sence when explained in that way. I have a couple of weeks to finish a couple of things off and do the link and sync etc.

again thanks

Jon