I finally got my prechamber socket in today so I can pull them out. Let me tell ya, what a pain in the *%#^&*2!^*%* ass that was, I created new curse words for that job...
I have some advice for anyone thinking about pulling the PC's out of their OM606. First, pre-soak everything in a very good penetrating oil, one that attacks carbon is even better. I prefer and lovingly endorse Kano Kroil/Aero Kroil, its expensive but it is seriously GOOD stuff! It's saved my butt more than once and nothing works better for really stuck stuff. That and some heat. Anyhow, I soaked everything about a week in advance with Kroil. In the top of the retaining ring, combustion chamber end, and through the glow plug hole. Repeated applications of it too. My head was off the engine already and I think it would be easier on the engine but only if you pull the head off afterwards because a lot of carbon chunks fall out the bottom during removal. You also can't soak the PC's from the bottom if the head is installed and remove the tip deposits before they are drawn out of the head. I pulled the PC retainer rings out with the special spline socket. With some wood spacers on the bench (needed because the PC's protrude out of the head) I securely clamped the head nice n' tight to my workbench with a couple of C-clamps and I used a couple lead ingots to seat the clamps against as not to damage or gall the head with the clamps. The head was bare at this point, no cams, lifters, valves, springs, etc, bare minus the PC's. Next was careful preheating of the entire head evenly as possible with a torch. (I wouldn't risk oxy/acetylene for this, too hot.) A large propane or mapp torch might work but it needs to be decent size to preheat a hunk of aluminum this big. My propane is too small, I used an old school Turner plumbers torch that burns Coleman fuel but is specially modified to be safe to use, most are not! Anyhow I heated the head evenly to the point it was hot enough you wouldn't want to hold your hand on it for more than a second or two. Make sure to keep the torch moving while heating it up and doesn't hurt to add a little more Kroil while heating, it helps it migrate into voids. Once good n' hot, threaded the PC puller arbor into the 1st one (make sure everything is threaded good n' snug, it transmits the forces better that way and lessens risk of damage) and attatched the slide hammer and start pounding away with everything you've got! I have a big heavy duty slide hammer that is quite powerful and it took about everything I've got throwing blows to yank these things out. Each one took at least 20 good swings or more to even budge
They don't come easy! In between each one I paused to apply more torch to keep the temp up and needed a breather anyways! They all came out in the end. The bores got sprayed afterwards to soften the carbon for clean up later. I de-carboned the exterior of the PC's with a soft wire wheel on my bench grinder and the PC's and retainer rings are enjoying a hot bath in my ultrasonic cleaner for a while.
I use a blend of Simple Green with a little Ballistol and good hot water. My machine is heated too which heat makes a big difference.
That was tonight's escapade. Also toss in a picture of my fuel heater delete plate I fabbed up a couple nights ago, turned out nice!