• Mobile App For Android Now Online!

    Download it here. The app is searchable in the Google Play Store under Sailboat Owners.

    Sorry iPhone/iPad users, we are still waiting on Apple. :(

    Click the X in the upper right corner to make this go away

Lister-Petter AC1W Small Diesel Marine Inboard....Seized

Sep 10, 2019
5
Catalina 27 Catalina 27 San Diego
Greetings everyone,

I'm a newbie when it comes to forums and chat sites, so please forgive me for my ignorance on proper customs and courtesies with posting new topics.

For starters, I've already been down the rabbit hole on seized engines using google and other sites (You Tube) with little luck finding anyone with a Petter AC1W Inboard diesel. Not that this should matter too much. In any case, I purchased a Catalina 27 from a fellow who was just using the boat as a "Sneak-Aboard" for his young son. My guess was that this was probably a decent option, given the rental rates in San Diego versus the costs to dock a boat at a marina for $400 a month or so. The boat is in great condition, but the previous owner mentioned the motor was seized.

I've only tried to bar the engine over with the crank lever manually, as the battery was dead to turn it over with the starter. What's more, when opening up the Seacock, (Raw Water Inlet Valve), I didn't see any water fill the Seawater strainer. This was my first clue as to what may have caused this particular diesel to seize up. So, I pulled the water hose off the seacock valve nipple, to discover water coming through just fine. (Only about 1/4 gallon per minute or so starter coming through). I quickly replaced the water line to stop the water from flooding my bilge - and sinking my boat. Yes, probably not the best method with the boat in the water, but now I know the hull-through is faulty too; as I also discovered the valve is broken in the OPEN position. So, now I'm relying on whatever is clogging that line to keep water from coming in or going to the engine. It probably sounds more horrifying than it is, but the boat is still on the right side of the waterline for now. Once I replaced the hose line, all went back to the way it had been sitting for however long it was before I bought the boat.

Now, knowing that I can get water to the engine (albeit from a broken hull-through valve, which will be replaced at the next haul-out), I'd like to get the engine turned over/unseized. I should probably pull off the head (replace the gasket afterwards) to get a peak at the cylinder/pistons. I want to be able to determine, definitively, if the engine is seized and what may be causing it. Not being able to turn the manual crank with the decompression lever open is my only indicator, and it's definitely a good one. Having no Raw Seawater going to the engine is most likely culprit in this seized-up mystery, but is there anything else I should look into first?

It was recommended that I drain the oil and look at the viscosity/color to determine if there is "bigger fish to fry" (as in cracked block, faulty bearings etc.)

I've never really dealt with a Lister-Petter AC1W Diesel before, but it has all the same workings as any other small diesel. My goal is to get this motor to run (unseize it) so I can drive it over the boat yard and have it hauled out for bottom paint and hull-through replacement. Also, I want to have it surveyed out of the water for a proper appraisal. I figure a working inboard motor would help.

I sincerely appreciate and respect all serious recommendations and guidance. This boat is going to be used for our charity that teaches at-risk youth sailing fundamentals.

Thanks ya'll

John B.
 

Attachments

Last edited:
Jan 5, 2017
1,299
Beneteau First 38 Lyall Harbour Saturna Island
Welcome to the forum. Lots of knowledge here. My personal way to do this would be to get the boat on the hard soonest. Get a tow, borrow a outboard ,whatever then pull the engine if required. Much easier to work on at home then in the boat. It’s been a very long time since I’ve sailed a Cat-27 and I don’t remember how easy it would be to pull the engine but I know it’s doable. Keep us posted!
 
Feb 5, 2004
3,933
Tartan 3800 Westport, MA
Could it be AC1W? Anyway, it appears it weighs 187 lb., plus the weight of the gear. With some help I would take it home.

For the broken seacock, haul it and fix that ASAP!
 
Sep 10, 2019
5
Catalina 27 Catalina 27 San Diego
Could it be AC1W? Anyway, it appears it weighs 187 lb., plus the weight of the gear. With some help I would take it home.

For the broken seacock, haul it and fix that ASAP!
Yes it is, my fingers are faster than my brain. AC1W. I concur fully. I just discovered the Seacock issue last night, so now I'm changing my plans. Any ideas on how to get it unseized though? I've heard acetone and diesel leave issues down the road. I have access to PB Blaster etc, but is this an achievable/worthwhile item for this particular diesel?
 
Sep 10, 2019
5
Catalina 27 Catalina 27 San Diego
Welcome to the forum. Lots of knowledge here. My personal way to do this would be to get the boat on the hard soonest. Get a tow, borrow a outboard ,whatever then pull the engine if required. Much easier to work on at home then in the boat. It’s been a very long time since I’ve sailed a Cat-27 and I don’t remember how easy it would be to pull the engine but I know it’s doable. Keep us posted!
Thank you! Will do! After discovering the seacock issue, my new plan is to haul out the motor (bring it home) and get it towed over to the yard. The thing about San Diego - Everything is freaking expensive. I'm not even sure I would even be allowed to change out the hull-through myself even. The boat yards I've looked up here don't even let you paint your own bottom. I'm still learning the cruiser secrets for San Diego, but all leads point down to Mexico for cheaper boat-yards etc. In any case, I will continue to post updates on the progress. Like I mentioned earlier, "Googling" AC1W Diesel Engine doesn't bring up a lot of information. I've heard these are also referred to Twin Minis too, maybe?
 
Mar 29, 2017
321
Hunter 30t littlecreek
Engine seized as in will not turn most abandon vessels just need some lubes and gentle persuading to run again. ya gotta get to top pistons. if glow plug engine pull them. Or pull injectors. I use transmission fluid but oil works pour 1 ounce into cil and let sit. Get a breaker bar on crank and gentle try turn both ways slowly wework on it days until free
 
Jul 23, 2019
29
Hunter 18.5 Nameless Revelstoke
I have NO marine diesel experience but lots of engine repair/ rebuild experience..... that being said..... I wouldn’t try to make it run for fear of doing more expensive damage until I could isolate why it’s seized. First thing I would do is disconnect the drive line and see if it’s the source.

Can you find a way to decompress the cylinders, by relieving the valve pressure? You could pull the head off and see if there’s a dropped valve or a bad cylinder.sounds like a big task, hope you can solve it.