Hi folks,quick bit of advice needed please!the setup I’m currently using is twin rs550 motors direct drive to 38mm props with turnigy 30amp esc on each motor and am using 4700mah 2s lipos one for each esc.what I’m planning to upgrade to is 2 hpi saturn 20t 540 motors giving 140watts each.going by what I’ve researched it will work with the esc’s I’ve already got with a good increase in power to enable it to get on the plane a lot better.have checked what amps they draw on rc car forum and they’ve been dynoed at 19 amps so within 30amps or 40 amp blow on esc! Is it a case of suck it and see ? Any advice is greatly needed from experts .

Thanks for info dave but could struggle to put them 700’s in as I’ve put long propshafts in and really don’t fancy cutting them down to get them to fit!could put that down to first time ever building a boat and trying to get the perfect weight distribution without adding ballast

Think I’ve got it sorted and I’ve changed the motors to hpi gt550(rebadged johnson st550)also changed props to raboesch 3 bladed 40mm.have tested it in bath and under load each motor pulls 10amps on my ammeter.the same ammeter I use to check output of alternators.forgot I had this tool until rummaging through toolbox lol.

Do your motors have the inbuilt fans like mine have? Just puzzled as to why you’d need to add extra fans.

hi folks,just a quick update on my mtb! have changed back to my old motors speed 660 and have noticed they're also johnson motors as well .have checked amp draw and they're pulling just over 5amps each and should give a lot longer run times. the only time i get off work and decide to test the new setup and the council decide to empty the boating pond for cleaning grrrr.