Mercruiser not starting need some ideas

gdpalumbo

Seaman
Joined
Mar 18, 2009
Messages
50
Hello everyone,
I recently purchased a 1988 233xl 25 foot regal ambassador. I only purchased the boat for 1,000 dollars with the trailer. The interior is in excellent shape and the trailer as well, it came with a new actuator and 4 new tires and new brakes. I figured the trailer alone was worth the purchase. When I bought the boat I was told it needed a manifold and I asked if it had ever been run with the cracked manifold and I was told no. The guy seemed very honest with us. We bought the boat without hearing it fire because he said he had it winterized 5 years ago and hasn't run it since. We got it home and first thing we found was that the motor was locked up. We poured some mystery oil in the cylinders and let it sit for a few days. We removed the pulley on the balancer and welded up a bar to bolt to the balancer to free the motor up and we actually got it to move. The motor is now cranking over with the starter but will not start. We have spark. We did the thunderbolt ignition test and found the ignition sensor in the distributor to be bad so we replaced it. We have a spark at the plugs but it looks very orange to me instead of the normal blue color but will still jump a pretty decent gap. The motor still won't start so we checked compression on all the cylinders and found every cylinder to be at 60 psi and two to be at 90 psi. I realize with all my work on cars and such over the years that these numbers are low and probably too low to start the engine. I forgot to add that when we drained the oil there was about a gallon of water that came out first. This doesn't bother me a ton because I'm pretty sure the crank and lower end were completely emerged in oil that was sitting on top of the water but I do realize that some of that water definitely created moisture in the rest of the engine. My question is....do you think this could just be some stuck rings? And what can I try if anything to get the rings to free up? Going to try and perform a leak down test this week and I guess that will answer my question but I was just curious if anyone had any ideas for me. I understand we got the boat for a good deal but I was in no way planning on doing an engine. Thanks in advance.
 
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Bondo

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Apr 17, 2002
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I understand we got the boat for a good deal but I was in no way planning on doing an engine.

Ayuh,.... So what were ya plannin',..??

It sounds like that motor is junk,... parts at best,....

Either long block it, or scrap it, yer choice,...
 

alldodge

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Mar 8, 2009
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Well sounds to me like your guy wasn't very truthful. Either way, with a gallon of water in the oil pan and nothing higher then 90psi compression, I don't see a leak down test helping much. I think you have a cracked block, blown head gasket and the motor was not winterized.

I would pull the intake and heads
 

Mercruiser420

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Nov 24, 2015
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92
Just so I wouldn't have gone down without a fight, I would pour some mystery oil in all the cylinders (it will temporarily improve compression), spray some ether (starting fluid) down the carb (stand back when u crank) and the orange spark may be indicative of weak spark due to an undercharged battery, so charge it up some more. I'd disconnect the gas line too in case u have water in the fuel system. I'm guessing mercruiser 5.7/5.0. Of course the correct/safe thing to do in this situation is an overhaul, considering the block/head is not cracked.
 
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Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,762
It should start with 90 PSI although it will run poorly. Dribble a little gas down the carb and give it a spin. With spark, fuel and air it should run. But I agree, sitting five years with a gallon of water in the pan is not a good thing.
 

gdpalumbo

Seaman
Joined
Mar 18, 2009
Messages
50
The battery is charged enough and I had an engine starter on it while cranking. I will try the oil in the cylinders. I was surprised it didn't try to fire myself. We put fuel in (tank was drained and was empty) I can see fuel goinf into the carburetor when we pump the throttle. We did try starting fluid and it still wouldn't go.
 

flipbro

Master Chief Petty Officer
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Feb 8, 2013
Messages
830
Fun to try and get it to fire! But even if it does there will be internal issues. Never reliable enough to go out in.
 

gdpalumbo

Seaman
Joined
Mar 18, 2009
Messages
50
Agreed, I won't trust it on the ocean with my kids. Me and my brother will probably buy an engine for it I think. I found someone online that uses brand new Gm blocks to build their mercruiser and doesn't require a core for 1,800$. Unless you all have a business you recommend to purchase a new or reman engine from. Do you recommend spending the 800 bucks for the closed cooling if we are going to go as far to have a new motor?
 
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gdpalumbo

Seaman
Joined
Mar 18, 2009
Messages
50
Also, I see the freshwater kits come with a lot, but what about circulation? There is only one water pump on the boat and I'm
Assuming this will circulate the fresh coolant through the motor but what pulls in the raw sea water through the whole setup? There are no pumps in the kits
 

alldodge

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Mar 8, 2009
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40,722
You have yet to say which motor or drive your have, I'm guessing a V8 with an Alpha drive.

If this is true, your alpha drive has the pump in the drive and will move all the water the motor will need, if passages are clear and pump is in good shape.

Closed cooling for a saltwater boat is the way to go unless you don't plan on keeping it. Even if you don't keep it the resale value is much higher.

Yes you can pick up a new crate motor which does not require a core. Some reman also do not require a core put need to compare
 

Mercruiser420

Petty Officer 3rd Class
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Nov 24, 2015
Messages
92
Believe it or not, the best bang for yout buck is an overhaul as the experience/knowledge you'll gain is priceless... If you can pull the motor and have an engine stand ($60), the rest is cheesecake and lots of fun and knowledge. Just have it bored (if it needs to be...prbly does) and throw a rebuild kit on it with some oversize pistons and new bearings, gaskets etc...You'll have a brand new engine that YOU built. Me personally, I'd keep it seawater cooled as I don't like headaches, but if ypu dont mind headaches and spendindg $800 then switch to freshwater cooling.

PS. Boats are not meant to save money...they are for entertainment/fun...You'll end up spending the same if not more, so dont waste your time trying to save money.

Good luck
 
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