Seakamp 200420 zinc replacement


Any idea what is the zinc matching the Seakamp 200420 heat exchanger?

Seakamp just replied to me ​”¼  npt thread zinc is 1.7 inch”

Checking on the association, I got recommended size E0 from this site.

They also have a page for the kind you screw into the brass cap – but you may have to cut that to length.

Anyway I had to cut to the length even the E0, as soon as it was inserted the water was not able to go through anymore.


Transmission stiff shifting and control cable replacement

Over the week-end, we had an issue with the transmission where it was not possible to shift to forward gear anymore.
Few minutes later and too much play with the gear control, I managed to shear the screw in the shift lever, as you can see in the picture below.
sheared screw in my catalina 36 shift lever
sheared screw in my catalina 36 shift lever
After a safe back-up to the dock, thanks a lot to the help of Philippe Guillaud and his family!
It’s now time to fix Hotel Catalina (again)!


This issue looks to be current with Edson Pedestal (as all other issues before :)), according to multiple comments online:

So the plan will be to:

  1. Remove the sheared screw from the lever
    1. How? Still need to figure it out
  2. Replace this screw:
  3. Check that the transmission shifts easily by itself to make sure the problem is coming from the control cable and not the transmission itself
  4. Figure out what size of control cables needs to be ordered:
    1. 14′ cable (transmission):
    2. 15′ cable (throttle):
  5. Replace the old control cables with a coupling nut (10-32) connecting the old and new one:
  6. Give some love to the engine parts who need a bit of painting:
    1. metal treatment:
    2. paint:
    3. Protect the fuel line from chafing, not sure how I missed them during my last chafing protection mission.
Picture from the control cable to replace
Picture from the control cable to replace

New priority project on Hotel Catalina! Let’s see how many week-end will I need to get it fixed 🙂

Helm tear down and fixing

Most of this section is coming from this document from Edson Marine. Edson Marine has been very helpful to answer my questions about the different part numbers I was not able to find around.
Edson Pedestal
Edson Pedestal

Remove the broken screw in the 960-A-938 lever assembly

During the issue the screw broke and the gear handle got free:
Easier than expected! I was able to get it out pretty easily with an easy out screw extractor after I drilled a small hole in it with a 1/16″ cobalt drill bit.
1/16" cobalt drill bit hole
1/16″ cobalt drill bit hole

Remove the compass

The 3 first ¼”-20 x 3 ½” ¼”-20 x 4” stainless machine screw came out very easily and of course as usual one didn’t come at all after a lot of drilling and one drill bit broken I succeeded to get the compass out with only one screw to replace!
compass broken screw
compass broken screw

Remove housing

Remove broken ¼”-20 x 3 ½” ¼”-20 x 4” stainless machine screw

At the beginning based on documentation and online information I ordered by mistake 3 ½” machine screws where needed 4″ long screws.
broken screw removing method
broken screw removing method

Lost lever assembly to control housing screw

Lost lever assembly to control housing screw
Lost lever assembly to control housing screw

I just had to send a quick email to edson to be able to order the needed screw on

Those screws are 8-32 pan head machine screws 3/8” long.

Remove screw holding the cable holder

I was doubtful about this part since it looks tedious to get it back there. But it was not as bad as it looked.
screw holding the cable holder
screw holding the cable holder

Engine room side work

 Now I am done on removing the different pieces on the pedestal side, I need to see how it looks on the transmission side.

Transmission control cable holder

Transmission control cable holder
Transmission control cable holder
Pretty rusty but not too difficult to remove.
Pretty rusty but not too difficult to remove.
Pretty rusty but not too difficult to remove.

Transmission control cable is now free

Transmission control cable before cleaning


Transmission arm removal 

Removed from the transmission but impossible to disconnect the cable from the arm 


 After some efforts the transmission cable is totally free!

Cables pulling

Time to put a coupling nut (10-32) and send the new control cables

Old cables removed

New screws from arrived

Cables replaced. Time to put everything back together at the pedestal

Now at the engine

Bracket cleaned and painted


Cables in place

Machines Screw too small for the housing!

First I went back with the old one before to replace them later on.

Compas LED crimping for easier removal next time

Everything is now back to normal!

This project took me 2 week-ends, and some painting at home. When it happens I thought it will take a lot longer, but it got fixed pretty fast.

More information about this process

Here more good information about this issue:

Engine high temperature water alarm issue


After the over heating issue we had last month, the water temperature alarm stopped to work. No sound anymore at the start of the engine.

After some troubleshooting it seems it was just a ground issue at the engine block level.

The wire with a resistor broke at one point and it seems to be the culprit for this issue

Ordered some 1K Ohm 1/2W Flameproof resistors:


Rebuilt it and it works great now!

M25XPB Heat exchanger leak


After 2 weeks ownership we decided to go out for a small cruise, still the stress of the docking and undocking of this huge to us boat. Fortunately we will not have to dock it back ourselves this time!

Just out of the marina we started to hear the noise of the high temperature alarm yelling at us. Time to turn off the engine. Calling the radio and getting a free ride to our slip by the cost guard 🙂

After few calls and some troubleshooting we realized the issue was a leaking heat exchanger. Learning the hard way…

I posted first these troubleshooting notes on the Catalina 36 user association, if you have a Catalina 36 I highly recommend to join as a paying member. You will get more content and receive mainsheet magazine once a quarter.


In the process to troubleshoot the leak we discovered it was the time to replace the heat exchanger!

Yesterday I removed it from its very unaccessible location. I will definitely mount it back aft at one point.

Once removed I was able to read the part number / SKU: Seakamp 200420 and take some measurements.

Now here is my question, do I replace with the exact same model? And where should I buy it?

Some pictures of the little guy 🙂

seakamp 200420 m25xpb heat exchanger 1
seakamp 200420 m25xpb heat exchanger 1
seakamp 200420 m25xpb heat exchanger 2
seakamp 200420 m25xpb heat exchanger 2
seakamp 200420 m25xpb heat exchanger 3
seakamp 200420 m25xpb heat exchanger 3

For the inches to mm value, I was using my vernier caliper, and not sure if it’s in metric or standard. So maybe some numbers are a bit off, also since I guess this heat exchanger didn’t move for the last 10 years, they are not the exact value.

So far I saw the required part there:

One other option would be to bring it to a radiator shop, have them clean it up, and give the outside a good coat of paint (or powder coat), but not sure about who I could ask to do that here in LA? And does it worth it? I have the feeling it needs more than a clean up.

Especially since it was leaking.

Heat exchanger replacement


So I decided to replace it with the SEAKAMP model shipped by Mr Cool (…(link is external)). For now, I just replaced in the same location at it was before, the ultimate goal is to move it aft, but I want to avoid to add more troubleshooting for now.

The heat exchanger came with brackets AND clamps as you can see in this picture:



So I felt a bit concerned about the brackets shipped with the HE, if I use them, I don’t see how I can use the clamps.

This is how it looked at first:


hotel catalina catalina36 seakamp 200420
hotel catalina catalina36 seakamp 200420
Updated my setup, look a bit more pretty, even if it will be way better when I will move it the way Matthew from Catalina 36 forum suggested it!

Radiator flushing

I also did few (ok a lot of them) flush of my radiator since it seems a lot of salted water has been living on the fresh water side of the cooling system.

To do that I used a Water Quality TDS Tester, cheap tool found on amazon ( to mesure how salty the remaining coolant was.

A temperature gun ( pointing the top of the thermostat and a lot of free time! Not sure it was really useful but it made me happy 🙂

Hotel Catalina M25XPB TDS values
Hotel Catalina M25XPB TDS values
  • TDS value was always measured during the draining step when the engine had cool down
  • Temp min was taken before to start the engine again
  • Temp max was taken just after I ran the engine for at least 10 minutes
Here a picture of the radiator flush cleaner I used!
Prestone radiator flush cleaner
Prestone radiator flush cleaner
I am now done with my heat exchanger / cooling system replacement for a while I hope. It was a very instructive process 🙂


v-berth insert fix


The Catalina 36 V berth is laid out with one large V shaped cushion and a separate insert to fill in the Vee area attached to an upholstered board that fits/rests perfectly onto the trim of the berth. Invariably, just as we become fast asleep, the insert falls to the cabin sole. Since our plan is to sleep on the v-berth to enjoy the nice custom mattress who came with the boat, it’s time to fix it!

The solution was to put some velcro tape:

I had to staple the velcro tape against the insert (update: so far after 5 months it still hold perfectly to the v-berth).






Marina del Rey
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