Help a noob with lots of questions

[Happy]

Hi I wonder if anyone can help me. I have a wltoys 915 RC boat that was ok until the esc/receiver broke.
I put a 30A flycolor esc link: https://www.aliexpress.com/item/1005005799418752.html into it however now I can't seem to get it on the plane anymore it just cavitates a lot. Not even full throttle. I can get it to move onto the plane if I keep the throttle down to bellow 1/3rd. The strange thing is if I set start power to level 1 on the esc it doesn't even have enough power to come out of the water and if I set it to level 9 it just cavitates.
Currently I have it set on lv 8 I may try lv7
Does anyone one know why its just cavitating at any throttle position above 1/3rd
The batteries I'm using is a 3s have not changed its position. it is the same turniggy 3s i used before the esc broke.
The motor is the same stock 1900kv motor
The only thing that has changed is this escc may be way more powerful so I have been looking for new props however I have no idea what pitch ratio the stock prop is.


The timing is set to automatic.
Does any one know if the auto setting is any good on this esc?

What size prop should i try ?
The stock one is a two blade 30mm propeller.
I found this site that sujests a 42mm but not sure if i need 2 or 3 blade prop https://www.radiocontrolinfo.com/inf...at-calculator/

[fweasel]

Auto setting for timing is a good place to start. Did you calibrate the throttle position after you installed the ESC? You'll need to make sure the throttle trim is set to zero on your transmitter before performing the calibration.

Also, you mentioned the boat would not come up on plane. Does it move it all? Is the prop spinning in the correct direction?

[Happy]

I did calibrate the esc @fweasel both trim and sub trim are both set to 0 before performing calibration.

I does move forward ... :-) Yes the prop is moving in the correct direction just seems like the prop cannot keep up with new esc

[fweasel]

Without seeing the setup in action, the only thing I can imagine is that the original ESC was suspect from the beginning and limiting power. The new ESC "shouldn't" make the motor spin any faster than the old one, rather provide more thermal and current draw capacity. So, under the huge assumption that the boat is now operating correctly, it wouldn't be the first time I've seen a mismatched prop for a given motor/voltage setup. It's possible the prop was damaged or the trim angle of the outdrive was knocked out of alignment.