1982 200hp high-performance "Franken-motor" hybrid build serial number 6033659 block casting has the J92W stamp

[acadian2022]

the 858-7790 is stamped bottom engine block below cylinder no 5 also added a gasket that was replace perhaps with the caliper indication the size could help

 

[acadian2022]

bade on AI
Based on the photo, your engine has a 200 HP (2.4-Litre) powerhead. A previous owner likely swapped the block or the entire powerhead onto your 1982 150 HP midsection.
Measurement Breakdown:

• Bore Size: The caliper reads exactly 3.375 inches (3.3" on the slider + 0.075" on the dial).
• Gasket Stamp: The factory gasket itself is stamped with 3.375 in red ink at the bottom right.
• Engine Type: A 3.375-inch bore is the definitive size for a Mercury 2.4L V-6 200 HP block. A stock 150 HP (2.0L) block from 1982 has a much smaller 3.125-inch bore.

 

[Dukedog]

you have a 1st generation motor.. its a 2.4 175.. pre '83.. its basically a 200 block with tha vertical front half instead of tha horizontal front half used on tha 200... nowhere near a "hot rod".. but preforms just about as good as a 200.. in fact some of tha 175's would run right with a true 200.. someone was not informed as to what it truly is.. probably believed what he was told somewhere down tha line.. it happens quite often in tha merc outboard world.. still a very dependable, tuff little motor if it was taken care of properly..

one reason it may show up as a 200 is tha way tha data bases are set up.. most that show that age motor are shown as a serial number "group" which will include 135 up to tha 200... most in tha "group" have a lot of parts that interchange all within that "group"... main difference other than tha block itself will be crank, rods and pistons.. most other parts will interchange (bolt on) with one another..... gl and hope ya get all straightened out....

another note: you have ta know what part goes to what hp motor because most of tha web sites don't distinguish tha hp that part goes to (some do, most don't) although they will bolt up and function on tha different hp's ....

 

[Dukedog]

jus something ya might wanna check is tha bore's.. they should be "chrome plated".. if they are steel then its had replacement sleeves installed.. if it has that done then tha rings will be different than "stock" rings.. chrome bores use steel rings and steel bores use chrome rings..

there are a lot of variables with these motors and tha only answer i can say is "experience" with all tha difference's

 

[acadian2022]

you have a 1st generation motor.. its a 2.4 175.. pre '83.. its basically a 200 block with tha vertical front half instead of tha horizontal front half used on tha 200... nowhere near a "hot rod".. but preforms just about as good as a 200.. in fact some of tha 175's would run right with a true 200.. someone was not informed as to what it truly is.. probably believed what he was told somewhere down tha line.. it happens quite often in tha merc outboard world.. still a very dependable, tuff little motor if it was taken care of properly..

one reason it may show up as a 200 is tha way tha data bases are set up.. most that show that age motor are shown as a serial number "group" which will include 135 up to tha 200... most in tha "group" have a lot of parts that interchange all within that "group"... main difference other than tha block itself will be crank, rods and pistons.. most other parts will interchange (bolt on) with one another..... gl and hope ya get all straightened out....

 

[acadian2022]

I can't thank you enough on your help my my.... I'm going to my last problem with this engine A arm advance timming WOT. when I manually pull forward the main trottle arm given full trottle C my advance arm A goes opposite to reaching the BTDC 22deg therefore may bugged down on the water again need it in the water asap. as soon as I touche the timming set crew B I lost my TDC+2deg that I setup with the timming light. I disassemble the hex bolt that holds both arms together clean everything check if all part are there 2 teflon busing the spring and the center metal dowel were the hex bolt goes in and still same result. I figure flip the spring orientation and same results. The hex bolt is just snuged not to teight not to loose

 

[acadian2022]

Good day. so I just came back boat in the water OUF when I discovered the bugging down at 2000 RPM my my I disconnected the trottle shifter cable and operated manually Wow hold on to the seat the Boat hit 3000 rpm and I could have given it lots more therefore I think its a link and since and still do proper timing with a real dial indicator 10/1 etc. so I've decided to now bring it in local Merc mechanic owner of store old school owner to finish off the setting however the owner of the shop told me there should be a black box something about timing delay of sort and we concluded it is not there and from my reading racers would have removed it for performance reason therefore I may need that box and given the mix match parts of this engine I'm not 100% what the part number would be? also the shop owner said the gearing may also have been changed not sure what to do about that if it has? I feel I'm almost there all please help as much as possible and if any ever want to visit NB free stay we have a huge house

 

[Dukedog]

tha box he's referin' to is mounted on top of tha air box stuff. will have a red, white and black best i remember.. they terminate on a switch box.. its called an "idle stabilizer".. looks like it is there in one of your pics? it has a piece of tape on it aligned with your makeshift pointer?.. it can be trashed... it sometimes has problems and really doesn't do much.. its supposed ta advance timin' if you go from full wide open ta idle very quickly.. supposed ta keep tha motor from diein'

 

[acadian2022]

yes I know what box your talking about some said it was my neutral switch most likely I got wrong info will check that box real good for ref number and wire ID. what about the gear for propeller if it was touched for example lighter boat etc could that potentially cause an issue down the line?

 

[Dukedog]

motor mounted neutral safety switch hadn't come out yet.. was a few years later.. but there should be a neutral safety switch inside tha control box

gear case?.. unless its been changed which is a good possibility is has whats called a pre-load gear case.. its a weaker design than a later model.... it still works pretty good though if in good condition.. it gets its name because of tha way tha top driveshaft bearing is held in place.. easily identified when its off tha motor.. has what looks like a dowl pin stickin' outta tha top of tha driveshaft.. it has a spring under it which compresses when installed holding tha top bearing in place in its race.. think it went away in '87 maybe.. went to whats called a ratcheting gear case.. for a few years.. that is tha most desirable case.. tha ratio will be 1.87 ta 1 if it hasn't been changed...

jus for your info.. all 2.0, 2.4 and 2.5 gear cases (all years) will interchange as long as drive shafts are same "length".. 20", 25",30" etc. yours looks ta be a 25", considered an extra long or XL shaft.. for every extra 5 inches you just add a X.. XL=25", XXL=30".. plain ole "L" is standard 20"..

 

[acadian2022]

awesome BIG BIG thank you I will pass along all your helpful informations to the Shop owner. I welcome any feedback and will continue to log in from time to time to read if anyone added more info have a great day

Thank you

 

[Dukedog]