Help... 2.4 Merc.... the story of!

Ok so here goes, I'm going to try this again... Maybe the fine folks of BFR can help!

....So, I got my Dads old race boat about 15yrs ago, since then the whole time I have owned it, buying parts or getting info on the 2.4 has been a FREAK'N NIGHTMARE!

I have been called a liar. I've been told I don't know what I'm talking about. I've been told many, many times that the 2.4 I have sitting in my drive-way doesn't exist....That Mercury never made the model I have in '78! I said all that to say this, If you are going to tell me the same thing, I'm use to it, expecting it, and am completely numb to it!

...So, here goes it is a 1978 (20") OFFSHORE 250hp 2.4 BLACK MAX, and yes, it said ALL those things on the cowl! Here is the next problem, because I'm a knuckle-head, the first time I took it out... I lost the freak'n top cowling, so I have no proof of what it said, other than "Hard to see" photos!

Why I am writing......I am giving-up try'n to dial this thing in! After 15yrs of thinking "I knew what I was doing"....I'm done! I need help! All the manuals that came with it, DO NOT have that freak'n model in them! I can never find ones that do, everybody over the years has given advise some good, some bad, on timing, carb set-up etc. but I'm still having problems! I have always wondered if becuase of the factory mods, things like timing etc. need to be set different than a stock 200..... Maybe I'm the problem, I don't know, but I want to be on the water, not at the freaking dock fixing it! Now because of age, I'm sure it needs rings and seals to get back to what it was... But I'm thinking I need someone smarter than me to take a look at it! I moved to NorCal and I realy haven't found anyone yet that gives me the "Warm Fuzzies" to take it to... Any help on where to go would be a much appreciated! ...I've tried looking things up on line, I talked to people, and to shops.. I've had this thing for 15yrs, trust me, I've tried to do right....

...Here is a few of my favorite things; Dosen't want to start when cold, hell even after it's warm sometimes, coughs coming off the line, cuts-out at mid throtle at times....but then runs like a champ at WOT!?!?! ....am I wrong to think timing and carb issues? I have set the timing/linkages/carbs to the factory specs so many times, I can do it in my freaking sleep! I'm seriously starting to think I am freak'n LEGALLY RETARDED! So the reason I'm ranting, after I gave up for a while and the boat sat for the last 5yrs, we took it out last weekend and I got to once again enjoy all the things I HATE about that freakn motor!

....Oh yeah, and now it will barely keep the battery charged!

Stats:
Heavy boat (Hallet 19' sport skier)
Heavy merc hydraulic "Parabolic" jack plate
2.4 (250hp they never made)
Bob's nose cone w/low water pickup
Ron Hill 24p Chopper

I was running high on the jack plate, 4 adults, full tanks, calm water, and trimmed to the moon.... 4.5psi fuel pressure, 30psi water pressure, the tach was right around 5500 (Can't remember for sure, seems low, but there was 4(Large) adults with me) and GPS read 61... Seems pretty good for the set-up and amount of folks riding with me right??? I can live pretty darn happy with my WOT for a family boat, I just want to fix the freak'n IDDLE to WOT problems!

...PLEASE HELP!

like most told u
the 1st v6 mercs from 76 up were 2litres
im no vintage buff ,,,dont know exactly what merc did when
but the 225 2.4s were 80 -82
but maybe with the offshore housing on there they released a 250 version
as the housing will add hp to rating,,,
was there such a housing in 1978???20" offshore???
yrs dont match but theres guys on this site that know vintage releases and dates

the 50 in the serial # dont show up on 1976-80 150-225 motors
the 1978 175 startsrun with 48 and 1979 starts run with 51
so can be a 1978 175 swivel section
as u know no 250 listed
so could be real,,,,,1off try for merc,,,,,,
or motor was pieced together many yrs ago,,,,,probably so

so if its life started off a 225 block which was not released until 1980,,,who knows????
with head off will be chrome bore,,, 2 transfer ports and 1 exhaust ,,,no finger ports like the later 200s,,,,
will have horizonal reeds with 14 metal pedals
and carbs shouild be wh-22 stamped in on top by the butterflys
if has these items then its a 225 block
and then would want to get a 225 manual to tune to

also with the spitting and hard to cold start
might want to pull intake and look for broken reeds
do a comp test to see if rings are holding or might have some peeled chrome
if comp is low,,,,should be around 125psi
good luck,,,again no nestagic expert
but do know its gotta be a 225 block assy if its that old of a 2.4
as 150/175s were 2.0 litre

Idle jets need to go smaller to richen them up. As main jets have to go bigger to richen them up. Dave

Don't think it is a "Offshore" no hood pin in the back top cover? Also it looks like the decal is MERC? not on a "Offshore" . I have never seen a Black Max on a "Offshore" cover? It has a "Offshore" mid. jm2c's. I will check the number at work in the AM.;)

More pics.... One more of the org. cowl and the rest are of the 2.4

...and more, I took the choke plate off, which I know, would aid in the "Hard-starts"

Looks to be a 150 or 175 block. Has 5 pedel reeds. Has a "Offshore" flywheel.
Boat looks to be a "Ski Racer" maybe post in that area?

that is a vertical reed motor,,,,,,,,,,,,,,
all the big hp motors are horizonal
the carbs are of the older 76-79 150-175 by #s and having a choke,,,,,,

when mercury started the 1 piece drop on cowl
on the twister motor
then went to the v 6s
all the factory stickers back then said mercury,,,,
merc came way in the later yrs,,,,,,
i had a twister 2x motor set up,2.4 formula efi set up with the original cowls and stickers
all i know is they were all mercury in chrome print,,,,,,,,,,,,,,

....and more

enough pics,,,,,no disrespect but,,,,
u have a pieced together motor
as i original thought,,,,,but trying to get benifit of doubt to ya,,,
without pics of the powerhead,,,
is older 1978 175 by the swivel serial #s
that 20" mid did not come on that motor
u have the production 2 piece tuner plate with the rubber seal
to fit the original clamshell style production cowls
some 1 put on the race cowl and mid
but didnt change to the 1 piece race tuner
to make it a full conversion