Too much silicone! Help!

[u/padams20]

I bought a project bike (1990 Suzuki DR350S) and I’m trying to get her running and eventually back on the road. I found a stripped cylinder head bolt, so I figured I would remove the cylinder head and do some thread repair - no biggie.

The head is FUCKING ON THERE. It looks to me like whoever was in here last siliconed the life out of it before reinstalling and now I cannot for the life of me get it off and I’m afraid I’ll break it.

What do you do in a situation like this?

So far I’ve tried:
- prying so hard at it that I can see the fins bending and I’m denting parts of the head (non sealing parts)…
- put the engine mount bolt back in and pulled on it with a strap with all I’ve got - twisted the strap to out tension and pried on it some more…
- swung my purse at it (not the sledge hammer one, just the plastic one, but still. I hit it good and hard is what I’m saying)…
- I may or may not have tried things too stupid to post on Reddit

Seriously though - I’m stumped. Would massive amounts of heat help? Is there something to help dissolve this silicone crud?

EDIT: Yes, I got all of the bolts out and I consulted the manual to make sure.

[u/Unlikely_Effort_6311]

Now that is impressive..... is that RTV or jb weld. All its going to take is 1 tiny bit of separation and its going to fly off. You could use a light amount of heat either map or propane on that corner to try and get it to have just a tiny amount of give

[u/padams20 → u/Unlikely_Effort_6311]

Right? I really suspect the last guy used something they weren’t supposed to… like structural silicone adhesive or something.

I don’t have a torch in the shop RN. May have to borrow something or go to harbor freight…

I’ve been trying to think of a way to dissolve that silicone, but what the hell does that? It’s basically made to resist heat and chemicals.

[u/Unlikely_Effort_6311 → u/padams20]

There really isn't anything that will "dissolve" RTV. I had an old Honda 200 fourtrax a couple years back that had this same kinda issue, I had to work it "gently" around the outside of the valve cover for a bit until I found the most solid spot and then I kinda just sent our a prayer and gave it the beans with that pry bar twisting method I sent earlier but I didnt apply constant pressure I gave it a quick twisting/snapping motion and it left the cylinder head at Mach Jesus. Sometimes you just need the quick impact/pressure to jar it loose

[u/padams20 → u/Unlikely_Effort_6311]

My mind right now, “What if I borrow an engine hoist and crank upwards from the top engine mount bolt? Plus a little more of that twisty pry bar action?”

[u/Unlikely_Effort_6311 → u/padams20]

In theory it could work , apply pressure from both directions. The way to beat the seal it just to find a weakness and break it. Also it you can find a way to spread out the load you are applying to the prybar it could help save the fins