Merc 300 engines true HP (I searched)

[Markus]

I have an 300XS power head with the DBR kit, lightened flywheel, and vented compressor pulley

is that pulley blue? What is the benefit?

(A couple of 300 XS just showed up, and I am trying to figure out what I have)

[Markus]

I've read the

300R is 316
300P ProXS 4S is 296
300 XS Opti is 307

Anybody know what the Verado 300 Pro makes?

what about the hpdi and the gen1 and gen2 etecs?

[engineermike]

what about the hpdi and the gen1 and gen2 etecs?

300 hpdi was 296 hp

[mikesufka]

I keep forgetting to comment on this thread ....

Years and years ago, I had a Spectre 30 with twin 300 ProMax’s and 15 X 32 Merc Cleavers ... ran 94-96 depending on the day and weight ... best ever was 99 mph

After a few years, traded for 300XS’s ... same props ... same speeds ... 94-96 mph with a best ever 99 mph

Spent numerous summers with both sets of motors on the same chain of lakes in Crosslake, MN. Besides a quieter and better running motor, the speeds were identical.

MDS

[JPEROG]

is that pulley blue? What is the benefit?

(A couple of 300 XS just showed up, and I am trying to figure out what I have)

Its lighter and vented to help cool the compressor.

Joe

[David - WI]

Besides a quieter and better running motor, the speeds were identical.

MDS

And more expensive? The 300 ProMax made 317hp consistently, when they were done tuning it... I heard.

[Jabe]

I have a pair of 300xs's on my Scarab. One is leaking oil into the cowling. The mechanics in the area are booked solid for 7 weeks. I would tackle it myself if I had a maintenance manual. I've searched the internet and manual stores and haven't found any mention of a manual for the 300xs. Is there one? Does anyone know where to get one? Is the 300XS configuration the same as another model that does have a manual? I hate to be stuck waiting for someday from the commercial mechanics.

[David - WI]

If you look at this 300XS Service Manual (currently unavailable): https://www.amazon.com/Mercury-Servi.../dp/B0035YUOTK

It's the same part number as this one: https://www.amazon.com/Mercury-Mercr.../dp/B00N9HLFOQ

BRAND NEW OEM MERCURY MERCRUISER SM HP 300XS DFI PART #90-8M8020345

Cheaper: https://www.boats.net/product/mercur...OV%20Parts%202

[Davidlake]

There is a thread addressing the oil pump o ring issue on this site as well as BBC site. The Merc manual does not address this. Merc says "buy a new pump - not fixable"