TOPIC: My Merc has an identity crisis

the boat is a 17' 1971 Kona. The motor cowling is for a 72 Mercury 1150 ELPT. no serial number on the transom bracket (not surprising). The stamp on hte block is 4604854P. I looked it up, and the list I found said this is a 1977 1500.
Is there a better way to know just what I have here?

Will

Will,
Most of the covers were interchangeable so there's a distinct possibility that someone wanted to make it a "sleeper" and changed covers. The best way to tell is by going by the engine block serial number like you did. I'm not that smart on the Mercs but I know many parts are interchangeable depending on the year of the motor. The good Dr. Frankenmerc is one of the experts here on modifying the Mercs. Smaller Mercs can be hopped up but I think In your case If the block crosses to a 1500 than it's a good bet it's a 1500.

Bob

I was thinking just a little earlier, that it started as a '72 1150, and the owner at the time torched the motor -didn't mix oil, or bad impeller- and just swapped out the powerhead. I guess it was all the same mid section and such.

Will

Pictures please, and all will be revealed.

Yes,...Pictures will help.
The wrap and cowlings will interchange as has been noted, but the '72 1150 powerhead can not simply be swapped out for a 1500 using the '72 drive shaft housing (DSH). Different exhaust configuration.
A '73 and later 1150 can be swapped out with a 1500 using the same (DSH).

Underneath the lower engine pan is a 'U' shaped cowl that covers the powerhead studs. Please take a picture of the area just in front of the front edge of the U shaped cowl.
Also please see if you can read to stamped number on the carburetors.
They are vertical on the front of the float chambers and start with WMK-
doc Frankenmerc

Carbs are WMK- 22.
Because of storage space, the motor is down, and full to stbd. I got a pic of the front of cowl on the port side.
I need to resize the photos, then I'll post them.

Will

Motor right side

Will,
WMK-22 is the correct carburetor number for a 1500.
But we'll need more to positively identify the beast, since the carburetors will fit an 1150 as well.
Like "Waterwings" Bob suggested, armed with the serial number that falls into a 1500 group & this carburetor number things are suggesting a 1500 is possible indeed.
However,...The serial number 4604854 is also in a serial group of the early 1150.
On the starboard side of the block is a cast number that starts with 852-
What are the follow (4) numbers?
On the starboard side also is a small black hose running from a fitting down low on the block up to a fitting on the block behind the flywheel. If the hose runs straight from the top to the bottom, I believe we can safely eliminate the early 1150, which would have additional fittings and related hoses up the starboard side of the block.
There are other differences between these beasts internally that can help in the identification, but I think we can nail it down externally.
doc

im at work now, so i got some pics up, but I wont be able to refer to the motor till i get home, likely after midnight.

Will

The attached picture has eliminated it from being a '72 1150.

doc

Anybody know the significant of the 'P' at the end of the serial number??

On the starboard side, number 852- 6450. One black tube, coming up from behind the fuel pump, running straight up behind the flywheel.
What the P indicates? I have no clue.

Will

852-6450 is a casting number on (2) of my confirmed 1500 Mercs.
So-o-o-o,...It looks like you have the beast of inline-6s!!
COOL!!!
doc

This could be a situation like my 1150 that now has 900 replacing any stickers on the outside. My Thompson is rated for a 90 hp motor. If you recalculate the horsepower of my '77 1150 with the new way of calculating at the prop, it comes down to about 90 hp and the boat handles it just fine. Someone might have hid the actual horsepower of your motor to match the boat.
Bill

The boat is a 71, so there is no tag stating motor hp. How it got listed as a 1150, I dunno. I was kinda wondering g how a lot 19 pitch prop was launching so well on a 115. Now I know.
Thanks, guy.

Will

I don't know if casting numbers will say much. I think they were probably the same on the post 1972 1150 and 1500. I don't have any 1150's to confirm this tho.. The 1500 just had the extra port cut into it. I know Jim Ruck will cut the power port into a 1150 if you pay him to do so.

Doc where do you get the WMK 1150/1500 carb breakdown?

I find it interesting the bottom valance is the correct style for the serial number. It almost steers me to think the lower cowling valance decal is correct... But just a hunch.

The P on the serial number most likely means Pace Maker. It was a program where Mercury rebuilt problem engines then re-sold them. Ive got a 1972 800 with Pace Maker stamped into it.

Conrad

Conrad,
I agree that the only sure-fire way of identifying the beast as a 1500 is to confirm there are boost ports in the cylinder walls.
I have managed to do this by removing a transfer port cover and feeling for the machined relief with my pinky via the notch for rod clearance.
"Doc where do you get the WMK 1150/1500 carb breakdown?"
If you are asking where I found the list of WMK numbers specific to a 1500,...I don't recall, but I documented the info at the time for reference later.
WMK-11 & 14 for short shaft & WMK 19 & 22 for long shaft. .082 for shorts & .080 for longs.
doc

And now on tho the bonus round. Does anyone conviently know the part number and vendor for a fuel pump kit and also a carb kit (set)?

Will

carb. kits

not sure what fuel pump you have.. but here's one kit

Hi I am reading through your comments, i am just wondering if the 852-6450 could be something other than a 1500 i have a motor that i am trying to identify, and the serial number looks like it was stamped by a blind school kids, and oesn't match with anything, but just above that is the 852-6450 which i can't find listed on any Mercury parts list.
sorry to jump in on this thread, should i start a new one?

I don't see any harm in carrying on with the same topic, but a different inline-6.
Based on your fuel pumps, it is either a first serial group 1500, or possibly a '73+ 1150, or possibly a 1972 1400 - which is the only model inline-6 in 1972 that had the later exhaust configuration.
Trivia note: The '72 1400 was a one year only, but when the 1500 model was discontinued after 1977, the 1400 returned in 1978.
The 1978+ 1400, 140, was actually a 1500 internally, but was designated a 1400 to avoid competition with the up-n-coming 1500v6. The 1978+ 1400 & 140 are a true beast. The late 1979+ 140 has the later ADI (6 coil) ignition, and my all around favorite inline-6. The later 1980s 115 is virtually the same beast, but with low dome pistons, and HP rated at the prop - not the flywheel. They run like a scalded dog too, and are a little more forgiving with the low dome pistons.
Block casting numbers, like Conrad pointed out, don't tell the whole story.
Check the carburetor ID numbers on your Merc.
They are stamped vertically on the face of the float bowl chambers and start with WMK followed by (3) numbers.
Example: WMK-14-1. The last number designates carburetor placement. 1 (or T on some means the top carburetor, 2=middle, 3=bottom.
To identify the horsepower. or model, I'll need to know what you find where I have "14".
AND,..Your lower cowl decals are from a 1976-77 model 1500, but like so many other inline-6 external parts, the lower cowl fits all model inline-6 and some inline-4.
There will be a test on Monday!! LOL
doc