Offshoreonly.com - Can the merc 250 v8 be remapped to a 300?

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Quote:

Originally Posted by WavetoWave (Post 4801652)

The PRO XS all rev to 6,200, the 250 Pro XS is the same as the 250R power wise (270 ish HP). The 300R has different cams, intake, ecu; makes significantly more than 300 HP. The regular four strokes have different exhaust and tuning. They may have different intakes but I don't know for sure.

The HP difference between a 250 ProXS and 300 ProXS is small, not worth messing with.

The real data is in the emissions reporting info. I remember seeing as high as 316hp, must have been the R.

I suspect the I6 may be on the way out and they go up to 350hp NA.

Quote:

Originally Posted by iliveonanisland (Post 4801655)

it’s a 4.6 liter v8. Only 250hp is weak af for that large an engine.

Yes, I agree, it’s pretty tame hp from 4.6 liter. On the up side, it may be more durable than its higher output brother……. (Lazy engine, nothing’s stressed, longer life)
Only guesswork, I’m not a mechanic. 🙂

RR