New Motor Break In On Pre-Mix, What Ratio ???????

[Nikon Man]

I have a fresh 3.0L Merc 250 EFI that I'm going to be breaking in running 100% Pre-Mix.
I have 30 gallons of fuel in the gas tank and need to know what ratio to run this 30 gallons at for my break in period.

Thanks,

[EuropeanAM]

You'll get mixed comments on this question.... for sure!

I've always stepped the mix UP slightly for the first tank (perhaps 40:1), which has worked quite well on the engines I've built over the years.

[Flipping57]

Don, wouldn't it be best for him to use a petroleum oil and not a synthetic for break in.

[redline]

+1..

[Nikon Man]

Quote:
Don, wouldn't it be best for him to use a petroleum oil and not a synthetic for break in.

Absolutely, no motor should ever use "SYN" oil for break in, pure petro oil only.

[Nikon Man]

Don,

What's your recommendation after break-in for a running ratio of 100% Pennzoil Syn. ?

Motor will see around 6200/6500 RPM's from time to time and a few high speed runs now and then too.

[redline]

My opinion.....if you are going to run it that high {even for short intervals}...I'd stick with 40:1.....JMHO....:)

[EuropeanAM]

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by redline &raquo;</TD></TR><TR><TD CLASS="quote">My opinion.....if you are going to run it that high {even for short intervals}...I'd stick with 40:1.....JMHO....:)</TD></TR></TABLE>

I agree.... and I'd also recommend a Synthetic BLEND (at least until you have 150+ hours on the engine). Personally, I prefer a Synthetic Blend in ANY steel sleeved engine.