Loss of power

I purchased a boat a few months ago and it was running a little slow and using a little to much gas. It was even slower today and we changed the thermostat and if anything it was worse after but idk if it was related it was taking way to long to pull up wake boarders probably a few hundred yards before it hit 20mph floored. It had been slow before like having to floor it to get someone up but this was worse. We did a compression check and they were all over a 100 most 120-125 one close to 105. Now its dying worse and wont plane out or get above 15mph. The boat idles fine and shifts from neutral to reverse fine. We are wondering if this could be transmission not grabbing? Fuel Injectors clogged or letting to much gas in. Timing? Computer? It is a 1997 air nautige pcm v-8 351 ford direct injected

Today I looked at the fuel filter it didn't look to dirty. I took the boat back out and it got up to like 35 but still felt like 50% power.

Re: Loss of power

I would start at the spark plugs and work your way back. Sounds like your ruining on one or two cylinders. COILS? Harbor freight has a spark plug tester for under 10 dollars.

Good Luck

Re: Loss of power

Fixed: we changed fuel filter checked fuel pressure checked out fine..the spark plugs sparked to engine fine when out but checking timing we noticed the light wasn't working on a few wires so we thought wires might be the problem...we pulled the spark plug wires off while running and no change on cylinders 1 2 and 7 number 7 the spark plug was bad and the spark was all over the place not in the cylinder this was with a new spark plug I had just put in so I changed it out. number 1 and 2 we swaped plugs we ohmed the wires and even swaped wires they were fine..ended up looking at a firing diagram and somebody had swapped the wires of 1 and 2 cylinder. boat runs fine now. Had been running on 5-6 cylinders all summer and maybe even for the guy that owned it before me.

Re: Loss of power

Nice enjoy the rest of Summer Fall is great boating also.:joyous: