I am trying to help my brother get his boat going, long distance. He is in NY, and I am in FL. I have more experience than him, but you guys are the infinite source of info. I was hoping, together, iboats, my brother and I could solve his problems.
He told me that the engine runs fine on land, and idles up in the water with the warm up lever, but when he tries to plane out, he has no power. He said it sounds like the engine is running on one or two cylinders. he can't even plane, so I bet it's only firing on one cyl.
He checked spark with a new spark plug grounded to the block, and found weak blue spark, even on all four. I'm not sure he could tell the difference between massive blue and weak spark without seeing them side by side, but nonetheless, he has even spark. Next, he switched out power packs, with a used one we had lying around. No change. He is trying clean and rebuild the carbs as we speak.
I told him to check compression, but he doesn't have a gauge. He will check this tomorrow, but I think he is going to water test the boat tomorrow also.
What do you guys think, especially about the spark?
Any thoughts are welcome.