1983 85hp Chrysler: 0 Compression in bottom cylinder

[Shorebreak91]

Well, looks like I might have gunked this up! If you've seen my previous posts, I have an 85hp Chrysler that has been giving me some trouble since I bought it (would bog down and die after 25-30mins WOT). When I took apart and rebuilt the carbs, my first trip out maxed out at 10mph, so I took them apart again and had maybe 10-12mph on the 2nd trip out. This 2nd trip also featured a lovely 500lb water passenger when I forgot to put the plug in the boat and took on quite a bit of water.

Fast forward to now and my boat has been at a mechanic for 4+ weeks while waiting for its turn (only mechanic in the area that would even touch it). I did a recent compression test on the engine and found that it had 120 compression on the top 2 cylinders and now 0 at the bottom. The mechanic recently got to my bought and found out the same. He planned on taking the powerhead off to see if it was something more trivial than a hole in the piston, but he says the bolts were so frozen on the powerhead, it would cost $400+ in labor just to get it off. He thinks I should trash the engine and look for another one (he put a few calls out though I'm not looking to drop more than $1500 given that the boat was only $1K or so). I feel really sick about the idea that I might have caused the denotation in the cylinder (if that is the culprit) due to my re-building of the carbs incorrectly. Not sure if the Chrysler is worth anything to anyone with 2 working cylinders.

 

[The Force power]

IF...you can't do the work yourself and it does have a blown piston; you could look for a good used power head or sell it as a parts-motor.
e.g. Lower-unit / ignition components can fetch you some decent money

 

[Shorebreak91]

Yea, my mechanic said that the bolts were so fixed that he thinks it'd take a few hours with a torch to even get them off. That combined with the unknown nature of what the real problem is once the powerhead is off would set me back a couple hundred bucks as it is. Looking for an Evinrude, Johnson, Mercury, or Yamaha that is at least from the last 20 years or so as a replacement.

 

[The Force power]

Yea, my mechanic said that the bolts were so fixed that he thinks it'd take a few hours with a torch to even get them off. That combined with the unknown nature of what the real problem is once the powerhead is off would set me back a couple hundred bucks as it is. Looking for an Evinrude, Johnson, Mercury, or Yamaha that is at least from the last 20 years or so as a replacement.

You don't need to pull the entire power head to inspect the pistons, just the head to see/inspect head / cylinders / chambers

 

[Shorebreak91]

Sorry, that's what I meant. Apparently that thing is really stuck on.

 

[Tassie 1]

Put the money that you would have paid the mechanic towards a " newer " motor ( after a compression test, at the very least )
unless you like working on them more than actually using them.

Older motors are always going to be a lucky dip in regards to longevity,
I've had and still have several.

 

[jerryjerry05]

NEW ITEM FOR DIAGNOSING ENGINE PROBLEMS!!

Recently bought a snake camera for my Android phone. $11
Yup 11$ and it even has a flash light for taking pics.(get the one with the stiff cable)

37 years. The head bolts might come loose??? Maybe not.
Remove the port cover on the bottom cylinder and inspect the piston sides.
If it really has no compression? then some collateral damage will show on the side
of the piston.