1967 Sea King 6hp - Low Compression

[logan_menk]

Hello! I’m new to the forum but not necessarily new to boating.
I have a new little project. It’s a 1967 Sea King 6hp. It has low compression, but before I start looking into it, I’m worried about finding parts for this motor. It reads 42lbs of compression on the top cylinder.

Is there a good resource for things like a head gasket, rings, etc for these motors? I really want to get it running well because I have the matching 12ft Sea King aluminum boat. I’d love to get them paired and on the water together.

The model number on my motor is: VWB27906A
The serial number is: 76X11670

Thanks in advance!

 

[racerone]

I believe that is a motor the same as a CHRYSLER.------Your local MERCURY dealer might offer to help with parts.----Call them or look online.

 

[Nordin]

As racerone says it is a Chrysler, but it is the early model of the 6Hp Chrysler.
In late 60.es (1968 I believe) there Chrysler introduce some small low profile engines and they were in many different Hp ranges during the late 60.es and the 70.es. From 4,4Hp up to 7-8Hp.
Many parts fitted all these such as head gasket etc.
Your engine is different to these and your best source for parts is Franz Marine.
Maybe you find parts at Ebay too but try Franz Marine.

 

[jerryjerry05]

42# on the top cyl. what's the reading on the bottom?
Could be something as simple as a head gasket??
This could be the part# 27-F525529 does it look like this?
Found this on ebay 25$ ebay# 323634192003

 

[logan_menk]

The fitting on my compression tester was a little too long to fit between the bottom cylinder and the engine cowling. I saw such a low number up top and didn’t go an further on the bottom. I’m hopeful it is something simple like a head gasket. I’ll pull it apart today and inspect.

I’ll definitely look into Franz Marine. Thank you for the tip!

I saw that gasket on eBay too when I was looking. There wasn’t much info other than the part number. I suppose at $25 I could order it and if it’s wrong, send it back. I would like to have a little more confidence in it but that may be the route I take.

 

[logan_menk]

 

[logan_menk]

Unfortunately I found a hole in both pistons. That’s a real bummer. In everyone’s opinion, is it worth putting this engine back on the water?

 

[Nordin]

Logan that is not a hole in both pistons!
That is the pin which stop the piston rings to rotate.
This is normal, look at the cylinder walls for score when the head is off.
Maybe the rings are stuck from carbon build up.

 

[The Force power]

There's a LOT of crud build-up, as Nordin said; inspect the cylinder-walls.
Run your nails along the side-wall and feel if they catch??
If not I would start cleaning the gasket mating surface, be VERY careful to stay straight & flat !! with the sand-block. (or permanent damage will occur)
There's a good possibility that the head gasket was the culprit

 

[logan_menk]

Okay, I cleaned the pistons up a little. You guys are absolutely right. I’ve never seen a locating pin on the top of the piston! On every 2 stroke I’ve ever been inside of the pin is in the ring groove. How interesting!!

Now I’m back to suspecting a head gasket. I’ve been trying to find one but I haven’t had luck. I sent Franz an email so hopefully I can get one next week. I looked the old gasket over and really couldn’t find a spot that “looked” questionable. Time will tell.

I’ll clean the gasket surface up and go from there. Is there anything else I should be looking for while I’m this far into it?

 

[racerone]

Post pictures of old head gasket.

 

[logan_menk]

 

[racerone]

I will look at my leisure and see if I have a NOS gasket set with that head gasket.

 

[logan_menk]

I will look at my leisure and see if I have a NOS gasket set with that head gasket.

That would be greatly appreciated. I’d also be interested in a carburetor rebuild kit if you had one. It is a Tillotson MT91B.

 

[racerone]

I have a number of NOS Chrysler sets.------No carburetor kits.---Your location ?

 

[logan_menk]

I have a number of NOS Chrysler sets.------No carburetor kits.---Your location ?

Kingman, AZ

 

[jerryjerry05]

Comparing the old gasket to the new.
The holes don't need to be the same.
As long as the comp ring is the same it should work.
If the carb isn't too corroded??? it just might need a cleaning
and no new parts??
Just make sure the jets are clear.
A welders tip tool does a good job of cleaning the holes.