KHB

Hi all, I have a 440 that is in need of an engine rebuild and I am looking at my options. I am considering upgrading to a 550 motor in the hull. I am also looking at a reman engines that SPT offers. The ski is stock with the exception of a west coast pipe. I realize I will probably have to improve the intake side if I go up in displacement. Additionally, I am not against rebuilding it as a 440. I am looking for advice. I know there are hull and pump differences and probably more than I am thinking about. I am a recrational rider and I want reliability. Sure a little extra power is alway nice, but is it worth the effort?

melscharf

Hello
The 440 to 550 upgrade is an easy swap, you will need a yamaha 650 carb cause the stock 550 carbs are garbage and you will need to make a spacer plate about 3/8" thick I make them out of a piece of plastic or aluminum between the intake manifold and the jugs. Also you should be sure to install a stainless prop in the 440 pump I would not change the pump the 440 is actually better.
Thx Mel

jonesy54

+1 to that. I was able to use the 440 carb on my 550 engine when I did the swap. I had to tweak the mixture settings a little but I've had 0 issues with since.

__________________
-1984 JS550 clone - restored, 440 pump, Skat Trak, primer, thumb throttle
-1987 JS550 - bone stock
-1990 X-2 - soon to be for sale