300/440/550 440 / 650 Conversion

[crazy4sand]

i have a few 440 laying around in my back yard i was thinking about doing a 650 conversion for jumping is a simple swap? meanning no hull cutting?

theirs a old 650 TS forsale on creigslist cheep is it the same 650 motor that fits in the standup?


just a little input will help me thanks.

 

[herbnerd]

yes the 440 to 650 is easly done,you will need to pick up a conversion bed plate there are a few people on here that sell them.or you can mod the stock 440 to fit the 650 .the ts electric box is bulky so you will need to mount it some where .i built brackets to mount mine to the block but made it a floating one so its not close to the heat.good conversion and good power.i believe you will have to reinforce the pump also,i have heard the 650 is quite a bit of power for it and will blow it out,or just switch to a 550 pump.there are a few build write up about that here and on pwctoday.good luck and have fun.take your time and do it right.

 

[crazy4sand]

thank you, next question 440 good for flatwater jumping? im 5'11 210lbs?

i plan on doing foot holds and probaly handholds

 

[herbnerd]

despite what other people think its you who will determine that.ive seen guys ride those in surf .everyone has a starting platform may not be the best but you will learn to handle it.not sure about back flipping or barrel rolling one but im sure if you tried hard enough you could.footholds are some work to put in and to turf them is an art.the glass work isnt hard to do but i had a hell of a time trying to turf and mine looks like .

 

[betrezra]

I've got a 1986 JS550 with a 650 swap and it's a fun little ski. It really changes the character of the ski...... it now goes 45-49 mph (hangs with a stock SXR), it weighs more...... so it's more to deal with in the surf, but the weight is actually nice on a buoy course for handling IMHO, it's worlds more reliable than the old Piston Port 550 it replaced.

My setup: Stock 650 out of an X2, 650 Stator, WC Pipe, WC Ex Mani, PJS water box, 46SBN Carb, St Pitch 19 prop, bored exit nozzle, top loader, ww cone. There are some good threads out there showing the details of the e-box hook up......to literally plug the 650 stator wires into the 550 ebox. I had to solder 1 wire. No big deal. And you use the 650 rectifier in the 550 ebox.... the cool thing with the 550 ebox is no rev limiter.

 

[Ram- man]

One thing to think about when putting all that power in a 440 hull is definitly reinfroce the front< where the front of the hood sits i crack my 440 hull almost in half with just a 550 motor in it and jumping it all the time, they used to make braces to fix the problem i am sure you could find someone to sell you some

 

[crazy4sand]

thank you for all your input

 

[poopski]

Adding turf and footholds is one of the best things you can do to a 440, besides adding a bigger engine. I used the 550 ebox also, theres a wiring diagram on here if you search. Heres a couple picks