Topic: New to the forum & have engine question

[pdx-m]

HI Mike from Portland, OR here.  I lucked across a 1976 CB550K.  I haven't owned a motorcycle in almost 20 years and I' loving this bike.  For the most part, the bike runs really well, but it has a small leak in the cooling fins on the left side.  I've never dealt with this before.  My other ride is a '87 Vanagon, so I do know work on mechanical issues.  Any help would be very much appreciated.  Thank you.

[MickB]

Welcome and these guys know all the tricks

[Gordon]

Looks initially like a base gasket leak (between head and cylinders).

'Round these parts we call that the head gasket.

[BobbyR]

Your leak is where the two halves come together which is fairly common. You can see it clearly when you open the pic and zoom in.  The question is how much oil are you losing vs the effort to fix it. If it takes a few weeks to get where it is in the picture you may want to wait.

[rb550four]

Welcome.
Cal is right about the clean and run. be sure to clean the engine  well so you are sure that's where the leak really is coming from when it shows up after a short ride.
 If it is head gasket ... well you'll be getting the head gasket for sure  but while you have it opened up you will also want to change out the O rings that are on the oil passages on both sides of the head level. and if the engine has original gaskets , you may also want to change the rest of them while you are there. a complete gasket kit is what I would go for.
Note: The pucks do not come with the complete gasket set. This you should know should you want to change them out too.
   This can be done in frame on a 550. So taking the engine out isn't a given ... unless you would like to.
    The carbs will be out, it'll be a good time for a carb cleaning while it's laid up.
And since it's been running poorly.... points, plugs,oil and filter change.Check and set the valves, the 3000 mile maintenance program.
  Shop manual, got to have  and read the shop manual.
If you needed to change out the clutch plates do it before you put the new oil in, and if you are doing that, it's a good time to change the shifter and kick start seals... which is also not included in the complete gasket set.I like to drop the oil pan and see what's in there , check the primary chain for slackness, clean the screen, The oil pan gasket and clutch sidecover gasket does come in the complete gasket set.
  Remember, that this is all fun and games, but it's serious. We are here to help if you get stuck, but you have to have your shop manual for your understanding and technical information. We really like pictures. This will be fun .           Really.