Which engine

Hello to all. I am new my first post. My question is which used motor would you all recommend. I currently have a 1988 mercury 150 xr4 on my 1988 pro-craft fish and ski and number 4 hole has no compression. Yes I purchased the boat knowing this. Rebuilding I understand in these parts runs between $2200 to $3000. So I am looking at used. I have found a guy who is a retired 40 year mercury certified mechanic that has two motors for sale that he went through a year or so ago and both have been run. He is selling them as is though with no warranty. One is a 1991 150 mariner magnum ll for $1600 the other is a couple of years newer 150 mariner not a magnum he wants $1800 for it. He is willing to take my old motor in trade and will knock $600 off either. Any help making this derision will be greatly appreciated. Thanks to all.

Re: Which engine

Before I go and drop $1600 to $3000, I would find out the problem with the motor you have.
It could be as simple as a blown head gasket and you can fix that for under a hundred bucks.
Even if it has a hole in a piston you can replace that for cheaper.
I guess it depends on what kind of mechanical ability you have, and how deep your pockets are.

Re: Which engine

Never thought of that. Although when I was running the compression check last weekend I did not hear any air coming out of the motor while cranking over on that cylinder, it would not even pump up. I can see where my motor has gotten very hot, the wire to the heat sensors on the head are both melted. My motor did not shift very well and there is also a charging problem, I just fingered I would trade off for one that has all the bugs worked out already. I have some other motor part he is going to take in trade so total out of pocket will be either $800 for the one or $1000 for the other. I am a pretty good wrench on Harley Davidson's and cars but have no where to do the work and have never worked on an outboard. Pockets are very shallow around here at this time of year.

Re: Which engine

Here is what your lookin' at. No comp. chances are not good on something simple and/or easy fix. Tha '91 is basically tha same as what ya got (a 2.4) only in a "fat" block version (only a 2 yr. run I think. '90, '91) with a 40 amp water cooled regulator which can be a pain. Tha later model is gonna be a 2.0 "fat" block motor (built for many years) with tha later style 40 amp with 2 air cooled regulators (lots better) and all tha newer "top" guided rods n pistons (depending on build date). With tha 2.0 motor your gonna give up just a tad in power but ya gonna gain with tha chargin' system. With what your doin' ya may not even notice tha difference. You might/might not need ta do some prop changin. Your XR4 has a small hub 1.78 gear if its still original. Tha later 2.0 motor will have a big hub 2 ta 1 gear. Again if original. Tha later tha year, tha better off your gonna be.........JMO

Re: Which engine

Thank you so much for the info. I did not hear the later model motor run, but he said he would be glad to put it on a boat and take me out on it to run it as hard and as long as I want to make sure I like it. I do know that the 40 amp charging system on the 91 went out and he replaced it with a 19 amp. I spoke with a friend of mine son who is working in a boat shop and he also said go for the later model if I could swing the extra cash. I will give him a call tomorrow and get the serial number for the later model so we know exactly what we are looking at. Thank you all for the excellent advice. I have to tell you that around here at least the pros are not very forth coming with info to us novice boat owners.

Re: Which engine

No problem. Glad ta share. If tha "newer motor" is not a Mag III or an EFI its gonna be tha 2.0 motor. But thats alright. Its probably tha most simple and "bullet proof" motor Merc built. GL with it............

Re: Which engine

I talked to the guy with the motors. He agrees the water cooled regulator is a pain and that is why when it went out he replaced it with the 16 amp. he says unless I am going to run a big amp on my radio that it works fine. He also says they both have the top guide pistons. He does not care which one I get O by the way the non magnum is only one year newer it is a 92 where as the magnum is a 91. I don't mind spending the extra $200 if you all think it is worth I just don't know.