[whiteriverrambo]

sounds like either a low compression or ignition. does it have points distributor or coil packs? could also be water in fuel. is it running rough or smoothly without power?

 

[whiteriverrambo]

have your coil packs tested. if you have a weak one it will not keep up when engine under load. and engine doesn't load much in reverse. its either that or your bottom cylinder is lost compression. usually comes from a water jacket leaking into heads, water then falls to bottom cylinder and will wash the cylinder wall and the oil doesn't provide protection anymore.

when you ran it at home did it smoke a lot? tail tail sign of poor spark. if its not dying under a load or died at home when reved up then your carbs fine. if there's rust on a plug when you pull it out it would show your weak cylinder. good luck