325 assault cutting out under load

[wolff supra21v]

I got a 2007 supra 21v with the 325 Assault 710 hours. the boat runs okay with no load or pulling the kids no weight in the boat. I might pop every now and than so I know something is wrong.
As soon as I put weight (3000 lb plus of water) in it and go to take off it starts backfiring and dies.
I replaced the fuel filter.
I replaced the plugs around 400 hours but I have never done anything with the distributor cap or wires.
I was thinking a complete tune up plugs, wires, cap. I was wondering where you guys been buying all this?

My only other worry is the fuel pumps. I do have high and low pressure pumps and wondering if one of those is going bad.
But I also think I am pass due on a good tune up.

[Stazi]

I got a 2007 supra 21v with the 325 Assault 710 hours. the boat runs okay with no load or pulling the kids no weight in the boat. I might pop every now and than so I know something is wrong.
As soon as I put weight (3000 lb plus of water) in it and go to take off it starts backfiring and dies.
I replaced the fuel filter.
I replaced the plugs around 400 hours but I have never done anything with the distributor cap or wires.
I was thinking a complete tune up plugs, wires, cap. I was wondering where you guys been buying all this?

My only other worry is the fuel pumps. I do have high and low pressure pumps and wondering if one of those is going bad.
But I also think I am pass due on a good tune up.

Probably way overdue for cap, plugs and wires.


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[PatL]

Symptoms sound like water in the fuel to me. I haven't had this with my outback but I had the exact same symptoms with a previous boat. Boat only acted up when under load. Might want to try a fuel additive like marine stabil.

[PatL]

Agree with replacing plugs wires and distributor cap too. Bakesonline.com is a good source for parts for our vintage boats. Good luck hope u can get it sorted.