The 4200 uses torque to yield head bolts and they can snap off in the block.
I'll detail how I have removed them with NO breakage.
Once you have all the other parts off to get at the big head bolts:
1) using a 1/2" breaker bar/10mm hex bit - loosen each bolt until the first TICK this is like 1/16 of a rotation - stop.
If the bolt will not budge - don't force it.
2) using a piece of 1" steel round bar as a punch and a 5 pound hammer - smack each bolt head 2-3 times.
3) using a 1/2" breaker bar/10mm hex bit - try to loosen the bolt - usually it will only turn a tiny bit more.
4) repeat step 2
5) repeat steps 3 & 4 about 3 times.
6) 1 at a time try undoing the bolt - some will come loose other will need more smacks.
Once you have a full turn on the bolt it should come out.
Main thing is to 'feel" what the bolt is doing - just don't yank on it. Some bolts will need to be run back near tight and then loosened off.
Patience pays off here.
Last edited by efi-diy; 12/02/18 12:07 AM.