No Compression in 2 Cylinders

[kcallowai]

Good Morning! ... my name is Keith and Im a newbie here, I just purchased a 1973 Catalina 27 for $1500 in San Pedro CA. The boat seems to be in decent shape except of course for the engine. The boat motor spins freely while attempting to start it and I can hear it firing and almost turning over. A compression test found that the front and rear cylinders have no compression.

I have briefly read up on the atomic 4 and from what I have seen, the valve springs are weak and can get stuck.... so my kneejerk reaction is to spray some Kano Kroil into the cylinder heads and let things sit in hopes that the valves free up. Is this the first course of action one attempts in this instance and is there another thread with an SOP for this? My motor is super tightly squeezed into the Catalina 27 engine compartment so Im not sure I can easily access the valve cover without pulling the motor ... thoughts on this as well?

Thank You in Advance
Keith

[Mo]

I too would suspect seized valves at this point. Continue to read up on various cases of this issue and try some of the suggestions. It would be a good idea to put in any info you know about the engine. Things like when it last ran and if you don't know what things are on it just use your phone to take a few pics. It's a good idea to lower the resolution on the camera when taking pics as well because the site here has a size limit.

[Ando]

See how it goes after soaking it in that oil and report back. I use MMO, but I think I do recall others using the one you mention.

I have a 1974 Catalina (and am in San Pedro as well consequently) and it took some getting used to fitting into that engine compartment. Luckily, I am of smaller stature and frame.

[kcallowai]

Engine

I too would suspect seized valves at this point. Continue to read up on various cases of this issue and try some of the suggestions. It would be a good idea to put in any info you know about the engine. Things like when it last ran and if you don't know what things are on it just use your phone to take a few pics. It's a good idea to lower the resolution on the camera when taking pics as well because the site here has a size limit.

I will be back out there this weekend and take some pics ... the exterior of the engine looks very good ... in fact it has the same bright bronze paint on it that I see on the moyer marine front page.

The boat had a survey done in January of this year so I know the engine ran at that point. The PO said it ran until roughtly 2 months ago. I think he also never closed the cooling seacock to the motor as I found it in the open position... my hopeful assumption is that he only used the boat and never did the required proceedure for start/stop/maintainance ...

[Surcouf]

you are not the only one there..

https://www.moyermarineforum.com/forums/showthread.php?t=11680

[Mo]

Sounds like you need to keep putting the penetrating oil to the valves. Here's what I do. I've never had to do it on my own boat but have sorted out a few others. I mix 1/3 transmission fluid and 2/3 acetone ( you only have to mix about half a cup)...it's a very watery mixture but it is just works wicked on stuck valves and rings. Use a flexible tip oil dispenser to shoot it right at the valves. Let it sit a few hours and try it...repeat as necessary. You need to change the oil as soon as you get it running.

[kcallowai]

MMO on valves

Sounds like you need to keep putting the penetrating oil to the valves. Here's what I do. I've never had to do it on my own boat but have sorted out a few others. I mix 1/3 transmission fluid and 2/3 acetone ( you only have to mix about half a cup)...it's a very watery mixture but it is just works wicked on stuck valves and rings. Use a flexible tip oil dispenser to shoot it right at the valves. Let it sit a few hours and try it...repeat as necessary. You need to change the oil as soon as you get it running.

Thanks for the good info, Im getting excellent repair and maintainance tips here!

1/3 transmission fluid, 2/3 acetone
8oz MMO with every oil change
TCW-3 in fuel at 100:1

I was out last weekend and added the Kano Kroil to each cylinder, then cycled the motor, added MMO to each cylinder and cycled the motor, then added MMO in each cylinder to let it sit for a week. I will be down there again in the weekend to see if anything unsticks / check compression ... if nothing frees up I will try the transmission-acetone concoction...

Thanks everyone for all the feedback ... I dont feel miserable and alone in this, lol!

[kcallowai]

Three cylinders now have compression!

I was out last weekend and added the Kano Kroil to each cylinder, then cycled the motor, added MMO to each cylinder and cycled the motor, then added MMO in each cylinder to let it sit for a week. I will be down there again in the weekend to see if anything unsticks / check compression ... if nothing frees up I will try the transmission-acetone concoction...

Thanks everyone for all the feedback ... I dont feel miserable and alone in this, lol!

Good News!

The front cylinder (of 2 that had no compression) now has compression, so thats 3 good cylinders out of four. I switched to the 1/3 transmission fluid 2/3 acetone concoction on this trip and am soaking the cylinders for another week in this stuff. BTW ...heres a funny.... I used a double plastic cup to mix it up and as I was holding the cup and squirting it in the cylinder heads, the acetone melted thru the cup and splashed everywhere, lol... live and learn!!

I did try to start the engine on three cylinders but it wouldn't fire at all due to all the MMO and penetrating oil that was present in the cylinders. What is a good proceedure to clear out the head of the cylinder properly so I can get a proper spark? Is all this MMO gonna gunk up the carburator?

Thanks Again
Keith

[Surcouf]

you did half of the job!! well done!


my 2 cents, but MVP's opinion are more valuable (by definition):
You should remove the carburetor for sure if not already done, clean it, then spray compressed air (those keyboard cans come handy) into the manifold before installing carburetor back. Regarding whatever is left in the pistons, a few seconds cranking will get rid of all that (if you really have a lot pooling in the pistons, crank without spark plugs but it is going to spray mix everywhere around the engine).

But once you fire it, make sure to change the oil. Not sure if the acetone and all the mix sent is very good for lubrication system..

[kcallowai]

you did half of the job!! well done!


my 2 cents, but MVP's opinion are more valuable (by definition):
You should remove the carburetor for sure if not already done, clean it, then spray compressed air (those keyboard cans come handy) into the manifold before installing carburetor back. Regarding whatever is left in the pistons, a few seconds cranking will get rid of all that (if you really have a lot pooling in the pistons, crank without spark plugs but it is going to spray mix everywhere around the engine).

But once you fire it, make sure to change the oil. Not sure if the acetone and all the mix sent is very good for lubrication system..

Sounds good! ... you also have an early Catalina 27... how difficult is carb removal given the tight fit of the engine compartment? I do have an access hatch on the manifold side of the engine... I do have the moyer manual so I will start learning about the carb now... any tips or comments on cleaning a carburator would be super helpful

Thanks
Keith

[JOHN COOKSON]

Good News!
Tall the MMO and penetrating oil that was present in the cylinders. What is a good proceedure to clear out the head of the cylinder properly so I can get a proper spark? Is all this MMO gonna gunk up the carburator?
Keith

If there is a lot of acetone\MMO or other liquids in the cylinders take the spark plugs out, lay rag across the spark plug holes, and crank the engine.
A heavy duty shot of starting fluid to the business end of the spark plugs will clean them up and make them usable, at least for awhile.

ex TRUE GRIT

[JOHN COOKSON]

Good News!

The front cylinder (of 2 that had no compression) now has compression, so thats 3 good cylinders out of four. I switched to the 1/3 transmission fluid 2/3 acetone concoction on this trip and am soaking the cylinders for another week in this stuff. BTW ...heres a funny.... I used a double plastic cup to mix it up and as I was holding the cup and squirting it in the cylinder heads, the acetone melted thru the cup and splashed everywhere, lol... live and learn!!

I did try to start the engine on three cylinders but it wouldn't fire at all due to all the MMO and penetrating oil that was present in the cylinders. What is a good proceedure to clear out the head of the cylinder properly so I can get a proper spark? Is all this MMO gonna gunk up the carburator (maybe, maybe not)?

Thanks Again
Keith

KEEP AT IT. If you can get the engine to start on three cylinders, which you should be able to, betcha the fourth will free up by itself. The carburetor might not need cleaning first - give it a try - what's to loose? You could try draining the carburetor but access is very poor on a Cat 27 so not sure you could do this.
YOU'R ONLY ONE STEP AWAY FROM VICTORY.

ex TRUE GRIT

[zellerj]

Please keep in mind that acetone is pretty flammable, and the starter my spark upon activation. So use your nose and sniff around the low points of the bilge, and if you smell any acetone or other fumes, wait until they clear out before triggering the starter.

[Surcouf]

removal of the carb in a C27 is not that bad; the worst part for me was the throttle cable, the pin refused to come out of the carburetor lever. I had to remove the whole cable assembly and put it on a vise... bad luck. Of course wear long sleeves, as there is a bit of suffering involved.

But I agree with the previous advice, before you try to remove the carb:
- make sure you water valve is closed
- make sure to crank without plugs a couple times, but with large rags on top of the engine and a piece of wood to avoid having the rags fly everywhere (thinking about it, a piece of old carpet would be ideal...)
- make sure everything is well ventilated, no heavy fumes below the floor
- put dry plugs back in, after checking they give you sparks
- and just start it, with start-pilot if needed. very good chance you get the last valve last this. You may have to run some time before it frees itself... check oil pressure and engine temperature during that time (cooling water valve back open...)

and if it works, enjoy the cold beer that tastes "I just avoided an engine removal"

[kcallowai]

Please keep in mind that acetone is pretty flammable, and the starter my spark upon activation. So use your nose and sniff around the low points of the bilge, and if you smell any acetone or other fumes, wait until they clear out before triggering the starter.

I did pick up a pump for doing the oil after (hopefully) all the cylinders have compression. My thought was to use this to suck any extra fluids out of the cylinder via the spark plug opening, then flushing and sucking out whatever is left in the cylinders to clear everything... was thinking of just using the leftover acetone for this... thoughts? should i use a different liquid to dilute the oil in the cylinders as acetone is somewhat corrosive and quite flammable?