300/440/550 85 js 440 to 650 Conversion

[Ancelmo]

I just bought a project js440 ski with a 650 motor which is pretty much complete just needs head gasket. I know i need to get a carb and exhaust. it also has the 650 ebox this is my first project ski i know the basics when coming to these motors but not all that savi not sure what else i need to get this running bought it for $250 thought it was a good deal just for the motor cause i was planning on this swap with my js300

 

[N2 H2O]

These are fun skis when they are set up right. The pump is the most important part of the whole equation. I would get a 550 pump. I run a 550 pump with a 15/20 impeller in mine and it hooks up great, but I have a pretty modded motor. I would suggest a 18* impeller for this ski. The nozzle is also very important. Ocean Pro nozzles are great, but they are rare. I would get a few different stock ones that have been bored to different sizes to try out if you cant find an ocean pro one. A stock nozzle has worked best for me because I only weight about 140, but most of the bigger guys run a bored nozzle. While you have the head off, I would have it milled. Milled heads really wake up 650s. I have built several of these and they all turn out to be a lot of fun. You will be glad you did a conversion once its all done and you ride it for the first time.

 

[Ancelmo]

It already has a 550 pump i checked that out today not sure if it has a stock impeller or not ill probably give that a look tomorrow im 6'1 and about 175 pounds i bought the ski yesterday so far im impressed with few of the parts it has on it. The js hulls are my favorite i like how they ride last summer i rode a kawi 650 loved its power but didnt seem as fun. cant wait to get this ski runnin :biggrin:

 

[caseville9036]

Looks like from the pic's that your ebox is a 440/550 one, not a problem because the wiring is pretty straight forward on the conversion ski's.

The new power in these fun hulls is great.

 

[Ancelmo]

oh i thought it was a 650 ebox because on the inside there is stickers that say 650 but must already have the 650 regulator ill post pics later and someone can confirm exactly what it is

 

[Ancelmo]

550 ebox

 

[N2 H2O]

It's a 550 ebox w/ a 650 voltage regulator. It'll be fine to use. Here's the wiring diagram to use it with the 650 motor.

 

[Ancelmo]

Thanks for the info will be really helpful

i opened the flywheel case this morning found out that i also need to get a stator and a bendix hopefully i can get them at a good price. I figured with my budget right now which isnt much that im going to pretty much build it stock and then work my way from there. Tomorrow i will start my preperation on the hull for paint.

Parts list iv come up with so far
650 carb with manifold
Reeds
Head gasket kit
650 stator
Woodruff key
Exhaust manifold with stock 650 exhaust
Bendix
Intake grate
Primer Kit
Waterbox

Let me know if there is somethings that im missing

 

[N2 H2O]

I know your working on a limited budget, but don't buy a stock 28mm carb. The later ones came with a 38mm, which would be fine, but don't buy the 28mm that came on the earlier ones.

 

[Ancelmo]

Yea im debating if i should get the stock 38mm carb or a sbn 44mm carb cause i already know either way i go im going to end up with the sbn 44mm eventually just depends when i wanna fork out the money for it

 

[N2 H2O]

Yeah my 650 ran great with a sbn44 on it


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[Ancelmo]

Was given a box of random jet ski parts mostly useless to me but tjeres a few good parts ill probably sell some if anyone wants anything

 

[Ancelmo]

So Just bought a dual mikuni 38mm carbs with westcoast manifolds should that be good enough? Any modifications that I'm going tto need to do for this set up?Oh and they don't come with a flame arrestor so if anyone has 2 for sale that will fit ill be looking to buy

 

[Mobile Chernobyl]

I have the K&N flame arrestor for the dual 38 setup (I had it on mine) with the velocity stacks that bolt onto the 38 carbs. I can't run it anymore due to a severly modified and lowered hood, so if you'd like it I can cut you a deal - send me a PM if interested.

 

[Ancelmo]

are they for the bn or sbn forgot to mention i have the bn set

 

[caseville9036]

The both mount the same.

 

[Mobile Chernobyl]

I have them on SBN, but ilke Caseville said - eitherway you'll be good to go. Shoot me a PM if you want them!

 

[Ancelmo]

blue nozzle up close picture for Caseville

 

[Ancelmo]

Randon question iv bern looking at jet skis on craigslist ind iv seen a few for sale that have no paperwork but they say that the DMV states that jet ski is in limbo after 6 years of not registering . what does it mean that it is in limbo?

 

[Ancelmo]

Finally got my dual 38s after 2 weeks of impatient waiting and now i need help with setting up the throttle anyome have picture or diagrams on how and what do i need to link them together?