mariner 175 with a old mercury block inside, Can anyone help me identify what engine

**appolageticsoul** · 07-01-2025, 02:31 AM

After being horse****ted around by seller i have come to realize this is not a 1997 175 mariner efi converted to carbs like he said but actually i think i have a totally different old block inside, Can anyone help identify what this actually is please so i can order proper parts when i need them. Had a idle misfire and 3 mechanics refused to ever touch it because it was not stock, forced me to become a outboard mechanic and a few simple tests showed failing stator which is on the way so i can fix it if i ordered the right one, i went with a 16amp stator i think is the right one for it, I think it came with a 9amp but should be good. Appreciate any help identifying this block so i actually know what i have , I come to realize this is one of those mutt motors thats been compiled from god knows what. People smarter then me are thinking 77-80 2.0 150 or 175 200 possibly. Maybe one of you can identify it. It is a ripper either way, does about 64-65 on a 4blade 26p prop or 72mph on a 3blade 23pitch turbo prop. Just wish the seller wasnt such a jerk but thats ok, karma comes around. I am really starting to think it is a v200 because it has the relief valve system towards the bottom on the side of the block and i dont think the 150 or 175 had that.

**skialot2** · 07-01-2025, 05:32 AM

Old bolt pattern makes it around 1980 or earlier.

**appolageticsoul** · 07-01-2025, 05:59 AM

Yeah for prolly late 70s to 1980ish Im trying to determine wether its a 150 175 or 200. The carbs are 1374-5427 WH3 models with the older rounded off floats which as far as ive found come back to a v200. The motor sure is fast, faster then a 2.0 150 would be in my opinion. It has vertical reed block for sure. Also, this engine has the relief valve deal towards the bottom of the block which i think only the v200 had if im correct.

**skialot2** · 07-01-2025, 06:21 AM

If it has vertical reeds it's not a 200. All 200's were horizontal reeds.

**Jim Speros** · 07-01-2025, 02:15 PM

The first 200 had vertical reeds.
https://www.mercruiserparts.com/bam/...44643/28180690

**tlwjkw** · 07-01-2025, 02:22 PM

look for a build date stamp somewhere around this part of tha block half.. may be hard ta find but its there.. tha hi perf motor is just ta show ya tha area.. tha production motors are in tha same general area and size...

**tlwjkw** · 07-01-2025, 02:48 PM

Originally Posted by Jim Speros

The first 200 had vertical reeds.
https://www.mercruiserparts.com/bam/...44643/28180690

i don't hold much truth with those diagrams.. they also show horizontal (200 stuff, one piece heads etc.) junk thats second gen stuff.. that **** shouldn't even be on tha same page.. stuff i know wasn't so with tha first gen motor... but hey its Merc sooooooooooooooo... jmo.

hell, Nitro built tha 200hp XR6........

**appolageticsoul** · 07-01-2025, 09:13 PM

Originally Posted by skialot2

If it has vertical reeds it's not a 200. All 200's were horizontal reeds.

Yeah unfortunately, that is not true. Look at marineengine.com diagrams It came both ways. The earlier models design1 came with vertical 5 pedal reeds and the design 2 came with horizontals. Also it had WH3 carbs on it and if you look at buckshot racing carb identifier the wh3 carbs came on the v200 only. I found tons of identifying marks but nothing that tells me anything also the heads dont have the 3 and 1/8 mark on them anywhere either.
top of head cap shows 1026-7261 and head shows 95081 and the biggest thing is the relief valve on side of block down low. I need someone who knows 150s to tell me if they have the relief valve its a two circle plate down low on block under the cdi packs. If the 150 175 doesnt have the relief valve as the parts diagrams dont show it on them then this has to be a v200. Also those head covers and head stamps come back to a 2.4l 200 so yep its a 200. Thank you all

**pcrussell50** · 07-01-2025, 10:12 PM

Is it possible that those early "200's" with vertical reeds were measured a different way, such as at the crank as opposed to the prop?

If so, then maybe that early vertical reed "200" is what became the later 175, since the 175 was essentially the 2.4/200 except with the vertical reed package from the 2.0/150?

-Peter

**tlwjkw** · 07-02-2025, 05:50 AM

i keep "hearin' 'bout a first gen vert. reed 200 but have never in my life seen one... i had one of tha first of probably 10 1976 merc's (that got me started with these things) in tha dfw area in 1976.. i've traded for or bought every horse power production 2.0, 2.4, 2.5 motor offered from '76 ta late 90's since.. jus cause they show up on some of these dia. don't make it so.. think tha old fiche plates would show TRUE parts list.. these list everyone refer to now are not true ta facts of tha serial number being looked for.. merc jus combined several things that do not apply ta tha earlier gen 1 motors in with their parts list.. why?.. i have no clue.. believe what ya want but as for me, show me with real facts, not jus something printed up by Merc.... jmo.

and yes.. first gen motors were "crank" rated...

**Jim Speros** · 07-02-2025, 11:32 AM

I had a buddy that had the first year V6. It was a 175. I can't remember for sure about a vertical reed 200. I have an old paper book merc parts catalog. I looked; it only went up to in line 1500. I gave my fiche away years ago. That would be trust worthy. I say it all started going bad when OMC went under. LOL Seems to me Merc hired some staff and things got silly. Soon after parts numbers started to change. There have been a few cycles of number changes prefix- 5 digit, prefix-6 digit. Most recently 8M numbers.
Initially merc would offer s/s and one could follow the part history thru number changes. I guess the process got outsourced and soon there was no way to verify old numbers. In the same dysfunctional way diagrams got edited. It got increasingly frustrating for me. I have new bagged parts from early OPTI days with no way to know what the current number is or any way to see what they go to.

So I hear you tlwjkw. I can't trust my memory past 30 years anymore and there are not many if any trustworthy ways to verify old stuff anymore.

**pcrussell50** · 07-02-2025, 12:56 PM

We know that the “current” 2.4/175 is a 2.4 chrome block with the vertical reed front end from the 2.0/150. So maybe that same motor when it first came out in the crank rating era, was called a 200?

-Peter

**skialot2** · 07-02-2025, 07:27 PM

Originally Posted by Jim Speros

I had a buddy that had the first year V6. It was a 175. I can't remember for sure about a vertical reed 200. I have an old paper book merc parts catalog. I looked; it only went up to in line 1500. I gave my fiche away years ago. That would be trust worthy. I say it all started going bad when OMC went under. LOL Seems to me Merc hired some staff and things got silly. Soon after parts numbers started to change. There have been a few cycles of number changes prefix- 5 digit, prefix-6 digit. Most recently 8M numbers.
Initially merc would offer s/s and one could follow the part history thru number changes. I guess the process got outsourced and soon there was no way to verify old numbers. In the same dysfunctional way diagrams got edited. It got increasingly frustrating for me. I have new bagged parts from early OPTI days with no way to know what the current number is or any way to see what they go to.

So I hear you tlwjkw. I can't trust my memory past 30 years anymore and there are not many if any trustworthy ways to verify old stuff anymore.

Cant say it's complete or not, but, Mercury's parts catalog gives you the superseded part numbers. Click the little plus all the way to the left. It will open to the superseded part number. Sometimes it goes several deep.

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**FUJIMO** · 07-02-2025, 09:48 PM

...first chrome bore 2.4's were vertical reed engines. crankshaft rated horsepower then, rated at 200 horsepower. made 1978 thru 1982. great running engines in their day. after the 225 was produced for a couple years, they re-rated the advertised horsepower to propshaft horsepower. the 225 became the 200. the 200 became the 175. the 175 became the 150...

**pcrussell50** · 07-02-2025, 09:58 PM

Originally Posted by FUJIMO

...first chrome bore 2.4's were vertical reed engines. crankshaft rated horsepower then, rated at 200 horsepower. made 1978 thru 1982. great running engines in their day. after the 225 was produced for a couple years, they re-rated the advertised horsepower to propshaft horsepower. the 225 became the 200. the 200 became the 175. the 175 became the 150...

Now that makes sense of it all... at least in my mind. Thanks.

-Peter