04 XLV with 350 vortec Indmar engine issues. Help!

I bought an 04 XLV back in February of this year with 510 hours and it has ran great up until the last 2 times i took it out. The last two times out it has ran fine up to the beach about 3 mile ride but on trip back while pulling tuber it has started busting up and bucking and backfiring like it is skipping or something but when I let off on throttle boat runs fine I can cruise back to dock at 13 to 14 mph with no issue but if I get on it or try to run above that speed for any period of time it will start busting up again. After first time it did it I changed out inline fuel filter the gas that I poured out had somewhat of a rust tint to it but after getting it home today I pulled filter and gas was clean and clear that was in filter. What should be my next troubleshooting step I was thinking maybe plugs wires distributor and rotor but they all look fairly new?

I would try to put a fuel pressure gauge on it and see if the fuel pump is starting to fail.

Have you pulled the distro cap to look at it and the rotor? Pull the plugs to check condition and gap?

Same thing happened to my 04 LSV. The previous owner didn't take care of winterinzing it correctly and there was a little rust in the tank. I had the fuel pump replaced and that solved the problem.

Sorry for delay in response been working all weekend. My next troubleshooting step will be to put a fuel pressure gauge on it. I haven't pulled the plugs wires or dist cap I did check all the connections of the wires to plugs and dist cap and they felt good dealer I bought it from said plugs and wires were just changed guess he could have been mistaken. TahitiVC was the issue with your LSV continuous or intermittent like mine I would think if the pump was bad it would be constantly bad but I could be mistaken?

It was intermittent. Boat ran great for 45 minutes to an hour towing the kids on the tube and then would barely come on a plane and wouldn't take any throttle going back to the ramp. Happened two or three times and I got it fixed hasn't happened since, knock wood

I am also having similar issues with my outback with 442 hrs. Do you have one fuel pump or two (low pressure & high pressure)

If it has two, indmar put out a bulletin about service/ maintenance of the small hvlp fuel pump. Search their site or bakesonline

I am doing the same for mine this weekend.

Took my mech. with me to river it took forever to recreate issue. The fuel pressure remained a steady 58psi whole time so we pulled dist cap when it started acting up and it had some condensation and a burn spot that looked like it was caused by arcing in the cap itself. So we replaced coil wire dist cap and plugs but I didn't get to test it after repairs due to having a tire blow out on trailer on way back to river. Patrick I have one fuel pump the one mounted to side of the engine.