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]

Originally Posted by 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.

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/for...ad.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]

Originally Posted by 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.

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!