Joe you know I know my Merc outboard stuff pretty well but am thinking of wading into early Merc I/O land. Jim you seem to know a lot on the older drives so I hope you are still paying attention on the board to help. I have a vintage Chris Craft with a Volvo 280 which is a piece o cake but not familiar with the Mercs. Now I have found a VERY CLEAN glassic a 63 that has a 4 cyl motor with what I believe is a series 1 drive.It even has the old football shaped control so that's gotta be a first year I/O which would be COOL!It has two sets of trim/shocks one set looks like merc outboard shocks and the second set looks similar to the long trim cyls like on an alpha 1...curious they are both there. It's white and jet prop.
I'm sure there is a list of to do things and please embelish but, I am curious if these use the dreaded steel shafts that will eventually not seal anymore. I assume these are set up like an alpha 1 where waterpump is in on top of lower unit? Are impellors avail still?
Are the gaskets avail to do the "must do stuff before you run it" maintenance? Out drive looks likes it has spent minimal time in the water so I'll take that as a plus.
WORST CASE SCENARIO: I have to replace with a modern 4 cyl and alpha 1 at some future point. How bad is that?
Any help insights would be appreciated on the old and new.
I'd like you two to weigh in before I even think about making an offer.
From what I understand (remember, I was 1 year old) the 1st MerCruisers were introduced in late 1961. So when did they actually become available to the boat manufacturers & to the consumer? Some time in 1962 I would assume. As for Mercury's electronic parts catalog, they show 1963 being the 1st model year and that is for a #1 drive with serial numbers of 1534572 thru 1684187. 1964 was for a #1A/1B/1C with s/n 1684188 thru 1777798. 1965 was for a #1A/1B/1C with EZ shift s/n 1776349 thru 2065189. Notice the overlap in serial numbers here. So, some were built with EZ shift & some without for a short time frame.
The differences between the drives in a nut shell; #1 used an outboard type shift spring loaded to forward gear and a 14" dia gearcase. #1A/1B/1C still used a spring loaded outboard type shift mechanism but had a larger 16" diameter gearcase still used today. #1A/1B/1C w/EZ shift used the crank type shift mechanism and shift interupter that has been in use ever since and still the 16" dia gearcase. The 1A/1B/1C designation had to do with gear ratios.
While they all looked very similar, there were differences at the bell housing to upper housing interface. 1967 is when the drive took on its most popular design that was used thru 1981. 1982 had the gearcase redesigned (designated as an "R") with squared off edges but internals were the same. 1983/1984 is when the "MR" was introduced. The MR looked just like an "R" but had the vertical driveshaft and lower gears improved. In 1985 they introduced it as the Alpha 1. Same drive, new name. The Alpha 1 was used thru 1990 then the Alpha Gen 2 came out.
Let me go back to the 1967 thru 1969 and some earlty 1970 models. They had a square prop shaft shoulder for the thrust hub & a different lower bearing carrier. Also, course threads for the prop nut. Later 1970 models used a tapered shoulder & fine threads. There were subtle differences internally from 1967 thru 1981 but in theory, the drives were interchangeable & WOULD bolt right on & work. I can tell you that there were some mid '70s drives with some type of junk alloy shift shafts used for a few years.
To answer your question about shaft materials (I assume rusting), 1967 and later with the exception of the above mentioned few years of junk shift shafts had no issues. Earlier years did.
Water pump impellers are available. As for entire gasket/seal kits, I believe that you will be OK there too. Bigger issue is the engine parts like hoses & manifolds. These were a breed all their own until 1967. 1967 & later you are OK.
As for the 2 sets of cylinders on the drive; The short ones are shock cylinders to absorb any impact. The long ones if there are for power TILT, not TRIM. TRIM became available in 1967 as on option and standard in 1968. TILT cylinders have one hose running to them, TRIM cylinders have 2 hoses running to them. The shock cylinders went away in 1967.
I have never worked on a #1 (14" diameter drive) I have worked on a few 1A/1B/1C w/EZ shift and lots of 1967 and newer.
Thanks Jim!!! Is motor a Chevy II GM 4 or a Renault 4, or other??? Does it have an overhead cam with belt drive...gotta figure that would need replacing just due to age and most likely impossible to find. Not to mention points must be non existant.
Sounds like I'd clean and treat with kid gloves till trouble shows and then have to upgrade all to ALPHA with more current 4 cyl. donated from a newer junk . Major effect on price of boat, as we all know this old glass just does not command any kind of money.
My reply was all based on the engine being original to that boat. (And remember that records are notoriously inaccurate from that era.) That will be a GM 153 CID used in the Chevy 2 cars. The Renault engines came out in 1965 with the 60 HP model that was later upped to 80 and eventually 90 HP. Those all used the Model "0" drive. Why a zero? Well, I always assumed that since the original drive was a #1 when they shrunk it down to use on the smaller Renault engines they called it a zero. But that is my just my assumption.
That engine is an overhead valve gear driven camshaft (no timing chain on any of the GM inline engines). The original 4 cyl was rated at 110 HP lated upped to 120. In 1968 the 181 CID was introduces, rated at 140 HP. The original 6 cyl models were 194 CID rated at 140 HP lated upped to 150 (230 CID I believe) then to 160 then 165 HP based on the 250 CID block.
Tune up parts are no problem. Points, condenser, rotor and distributor cap are all readily available. Like I said earlier, the manifolds were a problem. It wasn't until 1967 when they standardized the manifold & then used it for about 20 years.
Thanks again Jim, it's a 110. So Chevy II it is. That makes me feel better about it. Can I swap a later 60's lower unit on? It sounded like the early smaller ones were a one or two year only. I can add the shift cutoutif needed to save the shift dog.
Thanks again this is enormously helpful to understand what difficulties I may have if I need parts.
Like I said before, the interface is different from the bell housing to the upper gearcase housing prior to 1967. the difference is very slight, typically not visible to the naked eye. But the gaskets were different & the drives just won't mate correctly. If you are going to replace the engine, then find a 1967 120 HP with TRIM (1967 TILT parts are scarce) or any 1968 thru early 1980s 120/140 HP and swap everything including the transom plates. That will basically be a bolt right in proposition.