How to choose an old 2-stroke 150/175 Merc

[racerone]

Nope---I believe you refer to a " preload pin " on the shaft.----Has to do with thrust loads on pinion bearing.

 

[BWR1953]

Neither will I.......thank goodness. I figure another 3-4 years and I will have had my fill of "The Golden years".

My best friend of 40+ years passed in Dec 2021. I miss him every damn day. But, when I go, I believe I'll meet up with him again to go fishing once more.

 

[BWR1953]

sadly i just sent all my old motors to scrap.

i have to say the one merk that stood out to me was a 135 mariner / merk 2.0, i used that motor on a lot of boats , it was still a runner when it was sent to scrap .the advantage was there was no need to worry about finding parts as there was never a need to get any in the 20 years i owned it., FWIW the head gaskets were still original.
compatible power against a 150 how i used it was not an issue.

only issue i ever had was if i left old fuel in it i would have to take the carbs apart and clean them. i even used the same gaskets several times when reassembling.

one thing to note if looking at older 175s is the drive shaft can rust up and get stuck in the power head , i believe ( correct me if i am wrong ? ) its because they did not make the shaft with quality stainless steel , later versions had better stainless and a spring pin that i believe was to help get the gearcase free if it was a bit rusted.

Thanks for the info! At the moment, I have my eyes on what appears to be a 1991 175HP. It's been "pending" sale for about 5 days now and it's far away. I'm not sure that I'll try to move forward with it, but hopefully that year will be okay.

 

[Faztbullet]

You dont want it as it a 2.4L chrome bore ..same a the XR4 of same year.

 

[tphoyt]

My best friend of 40+ years passed in Dec 2021. I miss him every damn day. But, when I go, I believe I'll meet up with him again to go fishing once more.

I often wonder if we will get to see our friends and loved ones once again. Time will tell I guess.
I also hope that the fishing is good on the other side.

 

[BWR1953]

You dont want it as it a 2.4L chrome bore ..same a the XR4 of same year.

Never mind. I just did a little research and that chrome bore could be a real issue. Uhoh. Wassup with that?

 

[Dukedog]

'91 (first year of tha "fat block") anything is gonna be a steel sleeve motor... '91 175 should be a bottom guided steel sleeve 2.5 motor......... would be almost tha same as tha XR6... different tuner and carburetors.... normal size (4 3/4") gear case.

 

[BWR1953]

You dont want it as it a 2.4L chrome bore ..same a the XR4 of same year.

'91 (first year of tha "fat block") anything is gonna be a steel sleeve motor... '91 175 should be a bottom guided steel sleeve 2.5 motor......... would be almost tha same as tha XR6... different tuner and carburetors.... normal size (4 3/4") gear case.

Y'all are confusin' me.

 

[Dukedog]

tha "XR4 is and was tha only 2.4 steel sleeve motor from production ever built".. it was offered in '91 and was a 2.4 but was in a "fat block" design and over lapped tha XR6 in '91.. from 1991 everything from production was steel sleeve motors (no more chrome anything) and in tha new design thats called in most circles as tha "fat block" which is actually tha third generation block design... there no more original 2.0, 2.4 designed (outside looks) made.. tha "fat block" all production, 2.0, (2.4 XR4 '91 only), 2.5 motors from '91 on "looked" identical on tha outside.... tha new block design!
justa lotta time/experience involved ta get most of tha differences understood..... got most of tha "identifiers" down (pretty sure i've owned almost every merc V6 (2.0, 2.4, 2.5) model and horse power, both production and hi perf, they produced from 1976 ta 2004....but still learnin' a few tricks..........

 

[racerone]

Cast iron ( not steel ) sleeves I believe.

 

[Dukedog]

call 'em whatever ya want.. but if ya say "steel sleeve" most in their right mind know exactly what ya talkin' about................. its actually an iron alloy.

 

[racerone]

IT is very soft and easily damaged.

 

[Dukedog]

My best friend of 40+ years passed in Dec 2021. I miss him every damn day. But, when I go, I believe I'll meet up with him again to go fishing once more.

understand completely.. lost my best friend 4 years ago myself.. jus happen ta be my 48 year old son........ i'm gettin' pretty short on tha clock also...

 

[BWR1953]

Okay guys, that 175 is gone.

There's a 150 XR6 that I'm texting with the owner about. I can't tell from the pix if it's a 20" shaft or not. The owner went out to try to measure it, but couldn't get the tape measure in there. He sent me the serial number, but I can't find anything with that either.

Are there 2 data plates on these engines? I know there has to be a plate of some kind showing the max RPM somewhere.

I thought I'd read that all XR6's were 20" shaft, but can't find my reference.

Here's a pic of the XR6. Any idea on year? This pic makes it look like a 15" shaft, but it could be an optical issue with that big V6 hanging on top.

 

[jimmbo]

looks like a 20" to me
The Serial # should be on a disk, that looks sort of like Frost Plug on the Engine Block.
Looks like a late 80s/early 90s

 

[racerone]

Doubt that they made any 15" model V-6 motors.

 

[Dukedog]

there is one "sticker/plate".. its on tha tha clamp bracket.. tha serial number also will be stamped on tha motor at either tha welsh plug or tha port side block flange usually...

20"... '91 ta maybe '95. has tha small 1.78 ta 1 gearcase, plus cowl changed in '96... max from merc is 'bout 5800 i think but that don't mean much.. it will turn as much as ya wanna make it turn but under 7 grand cause of tha big ass flywheel (40 amp).. put tha number he sent up... there will be a build date stamped on tha port side block half as well.. if not on tha flange it will be on tha block half at base of number 2 cylinder.... that will tell exactly what year it is..

 

[jimmbo]

Spinning it faster than the Recommended WOT Rpm Range, will result is a Horsepower Drop, unless the Port Timing, Induction and Exhaust are modified.

 

[BWR1953]

Here are some pix of the outboard. The seller is going to check for more data plates later today.





Screen shot of video with the engine running.

 

[BWR1953]

Shouldn't there be a data plate or sticker somewhere with the max RPM listed?

I'll pass all this great info on to the seller so that he can figure it out. This motor is several hundred miles away from me, so I definitely want to get it figured out before I travel.

looks like a 20" to me
The Serial # should be on a disk, that looks sort of like Frost Plug on the Engine Block.
Looks like a late 80s/early 90s

Thanks! From the decals, I'm guessing maybe '91?

Doubt that they made any 15" model V-6 motors.

Thanks. I did find my reference which was from a thread on another forum. That poster said that all the XR6s were 20". I sure hope so!

there is one "sticker/plate".. its on tha tha clamp bracket.. tha serial number also will be stamped on tha motor at either tha welsh plug or tha port side block flange usually...

20"... '91 ta maybe '95. has tha small 1.78 ta 1 gearcase, plus cowl changed in '96... max from merc is 'bout 5800 i think but that don't mean much.. it will turn as much as ya wanna make it turn but under 7 grand cause of tha big ass flywheel (40 amp).. put tha number he sent up... there will be a build date stamped on tha port side block half as well.. if not on tha flange it will be on tha block half at base of number 2 cylinder.... that will tell exactly what year it is..

Thank you! I'll pass it on to the seller.

Spinning it faster than the Recommended WOT Rpm Range, will result is a Horsepower Drop, unless the Port Timing, Induction and Exhaust are modified.

Sooo... no nitrous injection?