1987 MERCURY Black Max SR2

[ronnie@69]

Was wondering what the rating were for the Merc SR2 Black max 150 back in the day..and the best things to replace on the engine to make it run better all info is welcome.. basically looking for common things to replace looks like most of the components on this 35 yr old out board need to be updated.. although it is running fairly

 

[Dukedog]

base 150 and XR2 150 are very much same thing.. XR2 uses different carbs, divider plate and tuner.. these will add a coupla hundred rpm to wot depending on your boat and how its set up... XR2? its more of a "marketing thing"... is it worth tha difference??? its up ta you..

with your boat, doubt you will ever see any difference with any (XR2) parts changes.... jmo

 

[Faztbullet]

Slap a new impeller kit in it with bases, throw away the stabilizer/advance module at set timing @23° and go to a stainless vented prop.

 

[ronnie@69]

Slap a new impeller kit in it with bases, throw away the stabilizer/advance module at set timing @23° and go to a stainless vented prop.

A stainless steel vented prop 3 or 4 blade.. what is the standard timing set at and will the 23degree change help the idol pickup

 

[ronnie@69]

Not sure what the impeller is or where it sits very new to The boating world

 

[jimmbo]

deleted. I misread SR2 for XR2

 

[ronnie@69]

Was wondering what the rating were for the Merc SR2 Black max 150 back in the day..and the best things to replace on the engine to make it run better all info is welcome.. basically looking for common things to replace looks like most of the components on this 35 yr old out board need to be updated.. although it is running fairly

 

[ronnie@69]

MY CORRECTION 1987 MERCURY XR2 BLACK MAX 150 ..looks like I posted SR2 instead of XR2

 

[jimmbo]

With differences mentioned above, the XR2 had a Fatter Power curve in the midrange, resulting in greater Acceleration. Both the regular 150 and the XR2 put out 150hp at their rated rpm, the XR2 just burning a bit more fuel doing so

 

[ronnie@69]

With differences mentioned above, the XR2 had a Fatter Power curve in the midrange, resulting in greater Acceleration. Both the regular 150 and the XR2 put out 150hp at their rated rpm, the XR2 just burning a bit more fuel doing so

Thanks for the info my friend

 

[jimmbo]

I'm waiting for someone to chime in that the XR2 was 165 because that is at the upper end of what an engine rated at 150 can actually produce and still be called a 150.

 

[ronnie@69]

That's certainly thoughts and theory of some individuals that I have communicated with..Some have made statements that the XR2 150 is actually a 165hp..I wouldn't know I don't have much experience with boats yet..

 

[jimmbo]

In 1986, I saw the Power and Torque Curves for the Standard 150 and the 1st XR2. The XR2's power peaked higher(not by much) than the Standard 150, but at a lower Rpm, and the power was dropping by the time the engine was a attaining the Rpm where it was rated at 150

 

[Dukedog]

tuner configuration/length....

 

[jimmbo]

That was one of the differences.

 

[Faztbullet]

Service school stated 160+ with the additional mods...all you would see on performance boats was your able to run one pitch size bigger. On Posters hull wouldn't see much difference

 

[Dukedog]

"That was one of the differences"

about tha only one that makes any difference..............

 

[Faztbullet]

We used to cut 1-1/2" off em (tuners) as we was going up against Junkrudes GT's and ran the 1.87 lower...doggy down low but would walk on out when it got to strung out.