Mercury 650, 800, 850 Identification

[boattinker]

I have several 1965 to 1975 Merc inline 4 cyl motors Some have Carb bases with straight accross bolt pattern, Some have tilted carb bilt pattern, One has power port pistons. Did all 850 motors have power port pistons? Did all 850 and 800 have tilted carb bolt patern?
Do all 650 have straight across carb bolt patterns? I ran serial numbers and found all the ones without powerport pistons had serial numbers in the 650 ranges. However some of those have the Tilted carb bolt pattern. Can ayone give me a rundown on how to identify which is which.

[150aintenuff]

try grubbs marine (http://www.oldmercs.com)
they have a good listing of SN cross references for most older models.... soon to be up to 1978... that is where i would start looking..

[boattinker]

Thanks, I have already been to the serial number charts a Grubb's. I am told that one can differentiate between the 650, 800 and 850 motors by pistons, carb bolt patterns, and carb size/number. Type of blocks as well. Ie, "Marathon" etc. Thought someone might be able to shed some light on the subject

[Blizz]

http://www.pfs-ware.com/kwast/ Go to this site and ask the same question and someone will be able to tell you thier all vintage guys over there.

[Ron V]

Boattinker, I'm not an expert on this, Raceman will probably chime in and answer your question better. But, to the best of my knowledge the 800s and 850s were direct charged (should have ports in the pistons?) and the 650's were crossflows (no ports). I'm not sure what you mean by the tilted carb bolts pattern. As for number of carbs, the 650s only had two, and as far as I know the 800s and 850s had two carbs as well.

At least some of the 650s also have the word "Panther" cast into the side of the block, but that may only be on the 62 cubic inch powerhead. The first ones were 60 cubes and I don't know if it was called the Panther at that time.

[Mark75H]

The pre 1967 60 ci 65's don't have any name ... the 44 ci 4 cyl was a much smaller casting and had "Super Thunderbolt" cast on them.

The 1967 to 71 63 ci 65's say "Panther" on the fuel pump side, Merc made them that way so you could tell them apart from the 60ci blocks without measuring the bore.

66ci 80 & 85 blocks say "Super Marathon" on the fuel pump side. All 85's are direct charge (but I don't know whether they all have power ported pistons .... probably yes; Dave S might know or have a more educated guess than me).

In 1969, 1970 & 1971 both 63 and 66 4 cylinders were made .... that is your over lap. I'm pretty sure the low serial number tilted carb stud fronts are 1969/70/71 66ci's. Check to see if they say Super Marathon

Did I leave anything out?

[Dave S]

You got it all about covered Sam. The only thing I can add is the 80 hp had no boost port, and were silver instead of black and the bolt pattern was the old style. ;)

[Mark75H]

THanks Dave. I was thinking about the paint color, but didn't remember at all when it changed.

[Raceman]

Begiining in 1970, the 4 cyl 800 and both of the 6 cyl engines were direct charge. The 70 model 4 cyl 650 was still a crossflow. All of the engines in 70 and 71 still had the old bolt pattern at the bottom of the powerhead. The 72 1400 was the first with the new bolt pattern, making it unique for that model year. In 73 the rest of the 4 and 6 cyl engines changed to the new bolt pattern. In 70 through 72 the big 4 cyl was rated at 80 horsepower and again, were direct charge but without the boost port in the side of the piston. Also through 71 was a 4 cyl 50 and 4 cyl 65, both crossflows. In 72 the 3 cyl 650 was born. In 73 the big 4 cyl was upgraded from 80 to 85 horse with the addition of the boost port. The 73 1500 also had the boost port while the 73 1150 did not. This difference continued for several years. 72 was the only year that the 1150 and 1500 had different bolt patterns in the bottom of the powerhead, and also, the only year that Merc ever sold a shortshaft 1150. Sometime AFTER 1975 the 850's rating was again lowered to 800 (80 horsepower) but the engine retained the boost port. To the best of my knowledge, the 800/850's WITH the boost ports were the only 2 ring boost port pistons that Merc ever installed in an engine from the factory. Sometime AFTER 1975 the 1150's got the boost ports also,but I'm unsure of the year. The 1500's were the first engines that Merc painted the powerheads black on, and the rest of the line followed, presumably in 74.

At times in these descriptions in the past there has seemed to be some confusion over direct charge and boost ports. All inline 6's from 1970 foward were direct charge, but many were not boost ported. Direct charge as opposed to crossflow refers to combustion chamber design, and not the hole in the side of the piston. Actually Merc's direct charge design is still a crossflow type arrangement, but they so designated it as DC to differentiate between the old and new designs.

[Mark75H]

I went back and checked, in 1969 the 66ci 80 preceeded the 6's as Merc's first Direct Charge model. As Raceman states, in 1970 all the big motors were Direct Charge and in 72 the 3 cyl 49 ci Direct Charge triple replaced the old crossflow 65 hp 4 cyl 63ci 4 ..... BUT the 44ci 50 hp was not discontinued for many years! It was called 50 hp until it was derated to 45 in 86. It was still being produced as a 40 hp well into the 1990s.

[Raceman]

Sam, I've heard my friend at Merc say on several occasions that the 1000 and 1250 Super BP's of 69 were the first of the direct charge engines and the production stuff followed in 70. I guess he was referring just to 6 cyl stuff. I never realized until now that the 69 800 was ACTUALLY the first production engine to have the direct charge design, but it IS clearly defined that way in the 69 catalogue as you say.

[Mark75H]

1969 was my dad's first year as a Merc dealer. I set up all the brochures, banners and posters .... and waxed the motors on the display rack in the front window (at least I didn't have to wax the boats! :) ). I remember there was a way cool 3D diamond in one of the display kits that I wanted to play with all the time after I got done inserting tabs A thru F into slots A thru F.

Before 1969 my dad sold McCullochs which weren't nearly as cool as the Mercs (nor as good looking!).

[150aintenuff]

the 44ci 50 hp was not discontinued for many years! It was called 50 hp until it was derated to 45 in 86. It was still being produced as a 40 hp well into the 1990s.

in 1986 tha engine went to propshaft rating as was billed as a classic 50... and into the 1990's it was again re rated at the prop to 40 hp as most were only 44-45hp @prop anyway so the engine was never actually detuned... just rebadged as 45 and later 40 hp.... and for reference the 44cid came out in the 1950's with the mk55 and mk 58's... good design if it held up for over 40 years.....

[Mark75H]

for reference the 44cid came out in the 1950's with the mk55

Mk55A to be exact. Only the 1959 Mk55A is a 44; eariler Mk55's were 40ci. Nick is excatly correct with the Mk58 starting out the 44ci Merc dynasty in 1958.

I wonder how many 44ci Mercs were made over the years .... it has to be the #1 produced outboard of all time. Some production data I have acces to shows probably 10,000 in 1958.

[150aintenuff]

I have a 1961 MERC 400 and its SN is 1307864 and a parts motor that is SN 1379985(also merc 400) so there were a bunch made in 1961 a well... i would gander a guess of around a total of 1,000,000 over a 40 year run... of 1 block design but more is totaly possible.....


mark 75h you caught me running from memory again... DUH... but atleast i only forgot a letter..

[Mark75H]

Merc serial numbers were deliberately deceiving. Sometimes there were gaps of unassigned numbers to inflate the total so the "enemy" at OMC would not know how many Mercs were made each year. My total of 10,000 Mk58's from 1958 comes from 4 or 5 sets of numbers assigned to Mk58's ... not from the first number assigned to a 58 and the last. The assignment of numbers also jumps from model to model along a line of numbers ..... 3,000 of model x, 2,000 of y, 1500 of z, another 1,000 of x, another 500 of z, 100 more x, 1,600 more y's, 3,000 unassigned, 100 more x, and so on ....

[150aintenuff]

I dont doubt that I just was giving the ### i had in my stock and also using the known fact it took chevrolet 40 years to make 1,000,000 corvettes i would assume Merc 40-50 hp 44cid would be a similar # if not more because i can name more people with 44cid mercs than i can with corvettes.

iu dont claim to be an expert on the older engines.. just the one i have (and i mean 1) but the knowlege i do have about it is correct.... so far.....