Hi I have a problem with my boat I just cant seem to get it to work in the water it started life as a 800 ep I fitted a 600 motor with two 7.2 bats went very fast for around 5 mins till the batteries cooked my mate got a nitro one thought that's for me My local shop sold me a 1.5 engine as soon as i put it in the water it just died had to put a very small prop on and it worked but it was very slow not a speed boat I have now got a 3.5 engine brand new but that go,s very fast till i put it in the water then i dies I have spend a small fortune on this boat new prop shaft engine mount my local shop is no help so can someone please help me im now thinking it could be my fly wheel is too small i have put in some pics of my boat I have got a few air boats that I have made as sort of gave up on this one but it is my baby my 1st boat please help me kind regards stewart

You have to get a.21 flywheel for it.the flywheel will keep the crank throw right/and it willl start easyer to.plus it

Before I saw misshydro's reply I looked at the shots and noticed that you don't have a flywheel on the engine, you need one! Once you get that installed, make sure that you run it a little rich. Airboats are a little easier to tune as the prop already has the resistance where a water prop won't get the load until it is in the water.