Merc 150 V6 to 175 V6

[QBhoy]

Hi all.

Having been immersed fully in the world of inboards for far too long, I’m just getting familiar again in the wonderful world of small light fast 2/ V6 powered boats.
Im half way through fitting a merc V6 150 2.0 2/ to my old boat. Rumour has it that these can be converted to 175 ?
Is this just a jet change or more Involved ?

Thanks

 

[jimmbo]

Since you never mentioned the year of either engine...

Likely the block, carbs, exhaust tuner, there could be differences in the Pistons and the Reeds too. Early(1976 - 1981) 175s, and (1978 - 81)150s shared the same displacement(does not mean the block is the same). In 82, the 175 started using the larger displacement block previously used by the 200 and 225.

 

[QBhoy]

Its around a 1990 approx
i thoight around then the 150 and 175 were both 2.0l blocks and the 200 the 2.5l ?

 

[QBhoy]

Maybe it’s the 135 and 150 that are 2.0l. Totally lost touch. I’ll look it up. Perhaps just nonesense marina chat. I think the xr 150’s have a bigger displacement. This is just a black max model.

 

[jimmbo]

135: 2 litre
150: 2 liter
175: 1976 - 1981 2 liter
175: 1982+ 2.3 liter
200: 1978 till sometime 2.3 liter
225: 1980 till sometime 2.3 liter

The xr2 in the mid-late 80s was a 2 liter block. It was ported and exhaust tuned differently than the standard 150. It didn't put out much more HP(less than 10) than the standard 150, but it had a different torque curve, had better midrange acceleration and burned more gas than the standard 150 do so

 

[QBhoy]

135: 2 litre
150: 2 liter
175: 1976 - 1981 2 liter
175: 1982+ 2.3 liter
200: 1978 till sometime 2.3 liter
225: 1980 till sometime 2.3 liter

The xr2 in the mid-late 80s was a 2 liter block. It was ported and exhaust tuned differently than the standard 150. It didn't put out much more HP(less than 10) than the standard 150, but it had a different torque curve, had better midrange acceleration and burned more gas than the standard 150 do so

Oh now you’ve confused me by saying 2.3l. I thought the bigger were 2.4 and 2.5, maybe even 2.6 litre on some cases. Haha.

 

[QBhoy]

Think there was a 2.4l 150 xr2 maybe. Seem to remember it for some reason.

 

[jimmbo]

2330cc is what the larger engine displaced.

in 1900. the XR engine was shown to be a 2.33 displacement

I know merc called their High Performance Lineage 2.4, 2.5...

 

[Dukedog]

ALL 135/150's with tha "exception of XR4, XR6, and 150 efi's are 2.0 motors up to somewhere in mid 2000's.. don't remember 'zactaly when tha 2.0 went away? All 2.0 blocks are basically tha same as for porting and such.. tha 2.0 XR2 production 150 had a coupla subtle differences with carb and tuner leading tha way..

PRODUCTION 150 MOTORS

135/150...2.0... '77 TO MID 2000'S? MAYBE A COUPLA YEARS LONGER?
X2...... 2.0 '83 TO '87
XR4... 2.4 '87 TO '91
XR6... 2.5 '91 TO ??

 

[Faztbullet]

The Xr2 was a stock 150 with: decals,200 divider plate,tuner advance box and carbs..made about 165HP....converted a ton of 150's to Xr2's.

 

[QBhoy]

Great info guys.

I suppose basically what im asking is are there reliable ways to get a bit more power out them ? Fancy reeds maybe ?
Long story, but I’m trying to get this boat toward the magic 70 mph mark. Having failed by 3mph with my main boat...haha.
Silly stuff, but it’s a long term goal I’ve had for years.

 

[Faztbullet]

What year your motor?

 

[QBhoy]

What year your motor?

Totally sure. Haven’t looked at serial number but I’m guessing about 88-92. It’s a black max

 

[Faztbullet]

Horizontal or vertical reed?

 

[QBhoy]

Horizontal or vertical reed?

Honestly don’t know faztbullet. Haven’t looked in there yet. Only went as far as a compression test, then disconnecting all things and looms for moving it onto the CVX.