Cylinder head stuck to cylinder

[1sttimer]

I have a CB175 and can't get the cylinder head apart from the cylinders. It is a 2 piece design and there's a gasket there but I can't help but think I am forgetting something. The cylinders are off the bike so it's not a stud issue. I wouldn't think the valves are presenting a problem. Should I have to remove the valves to separate?

I've had some good luck with a heat gun on the crankcase before but I haven't pulled it out yet. I wasn't sure about applying heat to a gasket even though I am going to trash it.

The whole attempt is to separate, soda blast, paint and add new gaskets.

Thoughts?!

Thanks!

 

[SONICJK]

It has dowel pins between the head and the cylinders.
Once youre confident you have the bolts out (i am unsure if there are any on a 175, look near the spark plug holes) take a rubber mallet and gently hit in an upward motion to separate the two.

 

[Tim]

Are you working with a service manual or parts diagram?

I quickly scanned the ones at CSMNL - http://www.cmsnl.com/honda-cb175-super-sport-k0_model7912/partslist/E01.html

There is a bolt it seems right in the middle between the exhaust ports. Did you remove that? 6mm x 45mm long. Looks like it passes through the head to the cylinders.

There are 4 dowels it looks like between the head and cylinders, which may be binding things together. That's a lot of dowels for such a small engine.

There is likely a small slot on one or both ends of the head where it meets the cylinders. Often put there for a large screwdriver to be used to pop them apart. Trick would be working it evenly from both sides, as doing it from one end only is going to bind those dowels.



You do not need to remove valves. Your gaskets cannot be reused regardless of their condition so don't worry about them.

 

[1sttimer]

Thanks for the quick turnaround guys. I have removed the chain tensioner bolt that you mentioned. It hooks to a slot on the spring loaded tensioner inside the cylinder. I will try the mallet approach. Those little dowels have been giving me quite the fit lately!

Thankfully this is my last component I have to disassemble, then on to blasting!

If I can't get it unstuck after these attempts, I'm going with heat.

 

[SONICJK]

Throw it in the oven if you cant get it apart haha.
I put the jugs for my SR500 in the oven to powdercoat last night and about 10 minutes into the cycle heard a crash so I opened the oven....the aluminum had expanded enough that it had just slid right down the steel sleeve and slammed into the bottom of the oven. So a few minutes at 400 and it should pop apart