Need help identifying Mercruiser.

[Starcraft Enterprise]

I found a great trade on a spare engine and outdrive from a junk hull on Craigslist. Even if the engine is junk, the outdrive parts alone are worth it. When the guy sent me the pics, I noticed that the Intake / Exhaust manifold is different from mine.
He says the hull is a 1968 Mark Twain with 120 Mercruiser. Mine is 1969 Starcraft with 120 Mercruiser. I have never seen a manifold like this before, can any of you identify it? Is he mistaken on the year and model?
I know if you go back a little further in years I might run into some problems.

 

[barato]

Re: Need help identifying Mercruiser.

outdrive is a Mercruiser 1, same as yours. motor looks identical to one that came in my 64 boat, but i suspect it is original for the 68 boat.

still may be an issue finding parts for motor and OD. if you have to replace, i'd look for something newer....80s and early 90s boats are out there & often cheap as fleas on a dog once floors get soft....replacing floors on fubarglass boat is a real bear and not worth for most folks. maybe try a "wanted" ad on CL?

 

[Kainon]

Re: Need help identifying Mercruiser.

I'd go with a 140, same drive ratio as the 120 - 1.98:1. The older 120's had a 2 peice intake, vs the newer 1 peice. there is a slight difference between the 120 & 140 intake to but can replace your 120 with a 140 or even 165 but that would require a different ratio drive though mine ran awesome on a 1.98:1 with a 23P Prop !!!

 

[Kainon]

Re: Need help identifying Mercruiser.

If you cant hear the engine run, at the very LEAST require a compression test. steer away from anything less than 120psi or more then 10psi difference from high to low. Working on them I've seen 120/140's have valve leakage or bad head gaskets.

 

[Starcraft Enterprise]

Re: Need help identifying Mercruiser.

If you cant hear the engine run, at the very LEAST require a compression test. steer away from anything less than 120psi or more then 10psi difference from high to low. Working on them I've seen 120/140's have valve leakage or bad head gaskets.

I don't really need or want the engine. The drive shaft oil seal on my current MC-1 upper unit leaked causing it to fail. All I need from these parts is the upper unit, if I can use any of the other parts, that is just bonus. I am just trying to confirm that the outdrive is an actual MC-1 and not a earlier 1A EZ or 1B EZ because they would be the wrong ratio. From what I have read I believe some of these outdrives (1A EZ or 1B EZ) was hooked to the 153 cubic inch 110hp GM engine. Does anybody know for sure? http://www.4shared.com/document/LCxp...nd_Histor.html
Since I did not recognize that manifold, I was afraid it was 110 hp engine. Example, this is that same manifold but I guess it is possible that the 120's got the same manifold too. http://www.youtube.com/watch?v=N3Bv3N2Jvs0
http://www.youtube.com/watch?v=necvq83UWlQ&feature=related
This is a super cheap (I have less than $100 in the trade) way for me to make my boat usable again for a while. I do not want to invest anymore money into this engine/outdrive setup. I have a very dramatic repower in the works and will not be able to use any of my existing parts.

 

[Starcraft Enterprise]

Re: Need help identifying Mercruiser.

Now I am even more confused.
http://www.youtube.com/watch?v=Ekf5y0I6AdA
and
http://www.youtube.com/watch?v=ZkyAl3BMVNM

I will just have to check serial #'s
If it is wrong ratio and still bolts together, I guess I will at least get to use the boat. I have already gone from a 19P prop to the current 21P. The little lower gears will probably just drop my top speed from 37 mph with 21P, back to 34 mph with 21P, what I originally had with 19P.