Below is my original post from 6/2/2002 regarding my power problem. I recieved numerous responses (all VERY helpful), and have finally solved the problem. After ignoring the good advise I got, I pulled the injectors out and had them rebuilt (not the problem), and payed a deisel mechanic to check the engine and adjust the valves (not the problem) in addition to everything mentioned below. Turns out my prop was fouled. I had it and the shaft cleaned by a prop shop over the winter when I pulled them to replace the strut and it appears that all that fresh metal was too much for the barnicles to resist. I just refused to believe that this could happen in 6 weeks time since I put the boat back in the water. Thus the idiot part. The good news is that I now have supreme confidence in my little Yanmar to behave and run like a champ, as well as having gained a TON of knowledge about intake, exhaust, and the fuel injection systems on the boat. Following is my original post: Yanmar Not Powering Up - I Read Archives Submitted by Glenn Newcomb on 06/02/2002 at 01:53pm regarding General_interest. and have tried everything I could find suggested in them to fix this problem. Here's the deal: My 2GM20F will no longer attain more than around 2000 RPM's in forward gear moving through the water. Used to run 3400-3600. It will attain 3600+ in nuetral and in reverse. It will also attain around 2450 in forward TIED TO THE PEIR! but not moving through the water. At 2000 RPM stops powering up, as I add throttle it blows black smoke and crud into the water. After a careful search of the archives and copious note taking, I went to the boat yesterday hoping to fix this. Here's what I've tried: 1)Hull is freshly cleaned/painted 2)Changed all fuel filters/tightened hoses/bled and re-bled 3)Ran brand new fuel from seperate can directly into manual bleed pump, eliminating current tank/hoses/Racor 4)Checked air filter/intake - sucks in plenty of air - will try to suck in a paper towel 5)Replaced mixing elbow 6)Checked entire exhaust system including muffler for blockage 7)Checked saltwater pump and strainer - pumps lots of water I'm at a loss. What do I do next and why on earth will she run higher RPM under load tied to pier than in transit? Fuel pump? Injectors? Help!