After several months of attempting to help my brother fine tune his engine via phone, I have finally been able to put my hands on it. I'm pretty close, but I thought I'd ask the pannel of experts.
Main problem: "Engine not firing on all 4". Carbs have been rebuilt, all new fuel lines replaced, new spark plugs gapped at .032", correct fuel mixture, etc.
Engine ran well for first hour, 5 people onboard the 17' deep V(unknown boat builder). Boat had to be fine tuned b/c it was not running at WOT. Carbs were sync'd, but the throttle was only opening 3/4ths of the way. I adjusted the linkage so the throttle would open up all the way. Spark advance was fully opened at the same time as WOT. (I am not an expert, but I think this is a correct sync and link). Next, I had to adjust the throttle cable so that the engine would idle down when taken out of gear. I know there is another way to adjust idle, but this worked, allowing the engine to idle down to normal and throttle up to WOT/full spark advance. All was well until it began to miss. We got back to the dock at WOT, not allowing the engine to idle at all, just coasted into port(I wanted to see the plugs after running hot with no idle ), then pulled her out. Bottom two spark plugs were dry and white. Top two plugs were charred black and dry, not wet. I noticed that gas was leaking from the male fule line connection on the top carb's float bowl when bulb was pumped. My Bro told me that when he rebuilt the carbs, he noticed that this connection would pull out of the float bowl easily.
I am goint to replace the float bowl and retry with fresh plugs.
By the way, compression was 118, 118, 118 and 105. 105 was one of the white spark plugs.
I checked spark via grounding a plug to the block and found = looking spark x 4.
Any input/feedback would be much appreciated.
Main problem: "Engine not firing on all 4". Carbs have been rebuilt, all new fuel lines replaced, new spark plugs gapped at .032", correct fuel mixture, etc.
Engine ran well for first hour, 5 people onboard the 17' deep V(unknown boat builder). Boat had to be fine tuned b/c it was not running at WOT. Carbs were sync'd, but the throttle was only opening 3/4ths of the way. I adjusted the linkage so the throttle would open up all the way. Spark advance was fully opened at the same time as WOT. (I am not an expert, but I think this is a correct sync and link). Next, I had to adjust the throttle cable so that the engine would idle down when taken out of gear. I know there is another way to adjust idle, but this worked, allowing the engine to idle down to normal and throttle up to WOT/full spark advance. All was well until it began to miss. We got back to the dock at WOT, not allowing the engine to idle at all, just coasted into port(I wanted to see the plugs after running hot with no idle ), then pulled her out. Bottom two spark plugs were dry and white. Top two plugs were charred black and dry, not wet. I noticed that gas was leaking from the male fule line connection on the top carb's float bowl when bulb was pumped. My Bro told me that when he rebuilt the carbs, he noticed that this connection would pull out of the float bowl easily.
I am goint to replace the float bowl and retry with fresh plugs.
By the way, compression was 118, 118, 118 and 105. 105 was one of the white spark plugs.
I checked spark via grounding a plug to the block and found = looking spark x 4.
Any input/feedback would be much appreciated.
