problems with my avenger 44

Hello everyone Im new to the forum but not rc or small engines but some what to boats.

ok I bought a AM avenger 44 with a toxicmarine 26cc and it's sweet other then I can't keep it running. OK when I got the boat the previous owner kept the prop (6717 3 blade) OK not really a big deal I thought. We'll I put the only prop I have on it (prather 270 2 blade) well I go to run the boat idle it up a lil bit and chuck it in. We'll it's cruising nice but once I start giving it throttle it'll get up but after about maybe half throttle it starts to (bog?) But it all happens so fast I don't have time to lift off or anything it shuts down? The motor will run for days on the stand has good compression clean plug clean coil surfaces. I'm stumped I asked the previous owner and he says the prop I have (prather 270 2 blade) is too big and causing it to stall out.

I don't get it I had this same prop on a 54" gull wing hull (v24 one design) with a echo 23cc with no probs other then it didnt zoom bcuz the small weedeater motor and it had a undersized carb on iT but it would run til I brought it back in and docked it. So could it really be over a prop is maybe something else? I've checked the carb out the diaphragm is good and very clean but I haven't gone real far into it. I'm just stuck I don't know if I should be trying to get my money back or go buy a prop

Check your carb settings as it should be able to spin that prop but it's not an ideal one for it. Two turns out on the low-speed needle and 1 turn out on the high-speed.

Even nitro boats will run great on the stand until they hit the water, it's the load of the prop in the water that changes everything.

Ive tried the carb settings and its still a brat lol. Maybe ill go ahead and pull it off and do a tear down on it

Also is there anyway a fuel bag set up could cause proplems?. The bag has been bled of any air and is almost full

An IV bag shouldn't be the problem, that's all that I use.

Yes, it could be a leak somewhere from the isolator block to bearings. Check the plug gap as I run them at .16"-.018". Plugs out of the box have too much gap.

Check the diaphragm in the carb to see if it's wrinkled. If you run pump gas that can give you fits. While you've got it apart, check the screen on the other side.