Originally Posted by
roverrescue
Hey mate
Essentially some of the big block yammies are good at leaking fuel down past the rings. Yam says it is their super hardened piston bores - I reckon it is just a company like Toyota that is very happy to live on reputation!
Anyways / the solution (even as per yam) is make sure you are propped right to the top of the rev range. Ie light load you should be hitting limiter - normal loads you have to hit 6000rpm.
So get your engine height right
Then the prop right
Then run them like **** at WOT for a few hours minimum. This will / should seat the rings and bores.
And then every time they are used make sure you hit WOT even for only
A few minutes
It is the only way
Oh obviously during the bedding in phase regular oil changes to ensure minimal dilation.
Those new engines at 23hrs need it most but the technique also works on engines with more hours
What boat is it
What numbers are you getting at the moment
RPM / speed at WOT
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