If you are in college, you are way too young to remember 12,000 volt coils! Plug gap is that small as the spark has to jump it under wide open throttle, and the low voltage coil in there isn't able to get the spark across any more compressed air than that!

A new chain will be a big PITA -- I just did the one in the 220D last week -- unless you have a helper. I had to use the visegrip method since Hans didn't have the nice Klann tool to hold the chain on the sprocket for the 615. For the 117, he has one -- bolts down over the sproket so the chain can't come off, has an opening for the swaging tool, etc. Just grind off the swage, unlink the old chain, link the new one on, and crank the engine around till the ends meet. Way too easy, destroys any vestige of moral fibers, etc.

Without it, you must have either two people, one to hold the old chain tight and guide the new one on, or use vise grips (three, please!) to hold both ends of the chain on the sproket. I got lucky, when I dropped the slack side, it didn't drop into the pan and I could fish it back up. I need to check the injection timing yet, but I think I managed to keep the timing correct even with the dropped chain -- cam and crank agree now instead of bein 12 degrees off.

Peter

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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!