I think I may have bent some valves by messing up valve adjustment. Cru RH350, Mark IV. When boat went in water I had a stuck hyd. lifter so I replaced all lifters. Engine restarted with noisy lifters. SO, I adjusted lifters (engine off - 1/2 turn after contact), left covers off so as to do running adjusted later. Tried to restart but when turning engine over heard a very weird sound. Engine was turning over but I have never heard that kind of sound. Like: "mmm, mmm, mmm". No ignition. re- adjusted valves. Checked for other problems - replaced carb, tuned distributor, re-set timing. Now the best I get is barely running, lots of gas, black plugs and hissing back through carb when it quits. Some valves will tick, tick afterwards like lifters are settling down. Push rods do not appear bent and will rotate freely, valves appears to go up and down correctly, but it will not run for a more than 15 sec and then load up. My fear it that I mixed up the adjustment sequence and had the engine 180 degrees out when adjusting the valves and therefore created my problem. Next steps? I am thinking of pulling timing cover and/or heads. Thanks for any input. Tim