proline2550
Cadet
- Joined
- Nov 20, 2004
- Messages
- 22
Original post was:<br /><br /><br />Just put my twin Mercruiser in after rebuilding the heads and re-ringing both engines after an exhaust shutter problem last year hydrolocked both engines on several outtings. With new fuel filters and all new ignition components, they both tested fine when run with the muffs on. While running slow and checking for leaks, I noticed the starboard side riser leaking and tightened the clamps. No more leak, but no more power either. After the repair, I got on plane and the starboard engine began to lose RPM and then quit after a half mile at 2300 RPM. Both engines ran at idle fine on the return trip to the slip. (a no wake return) The port engine runs flawlessly. Last night, I went down and removed the filter to find no debris or water,I replaced it anyway. I then swapped fuel pumps (electric) the problem didn't move to port. I removed the easiest shutter and again ran it to another stall within a minute or two. The engine spins freely, no evidence of liquid in the cylinders, after the engines stalls, I have good accelerator pump squirts, the choke pulloff is working properly, A vacuum guage test showed 20 inches of steady vacuum at 1000 RPMs, I keep thinking exhaust restriction, not fuel starvation. I meant to run the port side fuel hose to starboard just to eliminate a blocked hose, but forgot the stuff on my work bench.The problem remains with the fuel cap off so I eliminated a restricted vent. I am a mechanic by trade and have seen a lot of weird problems on gas, diesel, and propane systems but this one is trying my already limited patience. Put your thinking caps on guys, did I miss something? <br /><br /><br />After a lot of hair removal scratching my head swapping almost every component fuel and ignition related from good side to bad side and no result I hauled the boat , pulled the drive and no shutter parts at all! The only thing I hadn't done was feed the fuel pump with it's own source. A jumper to the positive lead made the engine run until I shut it down. It turned out to be a chafed wire that I had missed while inspecting the harness during the engine rebuild. a butt connecter and some heat shrinkable tubing and back in she goes tomorrow. Thanks to all that responded. You guys really helped clarify my own thoughts and question some other thoughts I had. Have a great year!<br />--------------------------------------------------------------------------------