i got this hovercraft, with a yamaha 600 sled motor in it. i want to know the exact sled it came out of... year too is possible. does the vin show the year?

i need an air filter for it, and i think i need to change the jets. anybody know where to get that stuff?

Well...it's been a while.  Mid 90's VX 600, 36mm Mikuni ???

Yea, I'm pretty sure the only twin 600cc sled motors yamaha made were put in the vmax 600's in the 90's.  Air filter wise, just put a couple pod filters on the carbs and don't mess with trying to find a yamaha airbox from that exact sled, they are just restrictive and don't filter much.  For the jets, they will be mikuni, just pull them and see what you have as far as the style of jet.

Oh, and that is a pretty sweet project!  I like the custom made pulley on the crank, how hard is it to pull over since it is direct drive?  Looks like there is plenty of room for improvement, maybe drop a big triple in there at some point??

The red seat is a dead give away,if its the original seat/motor it's a 97 600/700 sx.
When jetting keep in mind it was jetted to run at below zero temps,so its going to take some work to get it close,i usually go up 1 or 2 main jet size when i remove a yamaha air box and put uni filters on it,or leave the stock jets if i dont change any thing else,but do wide open under load/kill it plug reading to check it.yamahas are usually jetted fat from the factory,and i rarely ride when it's that cold.
I usually go up or down a jet size for every 10 degrees of temp change to start with and read plugs if i dont have a egt gauge on it (highly recomended)
So if you figure out the factory jetting in your climate is good for below zero,and you are going to use it in the summer,figure an average temp,say 60 you would start by going down 6 sizes and then add 1 or 2 because you need a uni filter which will lean it out.
Be carefull always jet fat first,plugs are cheap,pistons are not.

egesledder said:

I have the stock air box though, just not the filter element. I was hoping the restrictiveness would allow me to not have to change the jets. I believe the jets were already changed for the warm weather, im just not sure if they did the right size. It runs pretty good with the choke on or halfway on.

egesledder said:

Thanks…. Its not hard to turn over. Probably just as easy as the few ski doos I have. And for a triple, maybe at some point, but I wanna see how shell drive first. Its never been driven too far yet.

BDD1469 said:

Right, but as I already said in this post, I think someone already tried to jet it for warm weather, but it runs better with the choke on (but that’s with no air filter). So I think I need larger jets just by a size or 2? But I wanted to see if the airbox helped first. Or any filters for that matter. Anybody have advice on exactly what filters to get?

BDD1469 said:

Smaller jets for temp increase, and larger jets for a less restrictive air filter, right?

BDD1469 said:

Ya that’s definitely it… 97 600sx.. I got the gauge cluster with it and it as well as the seat are shown here.
http://www.chitownra...MAX-600-SX-Sled

BDD1469 said:

Will do. Where can I get an egt and how do u use it? I mean I know how to use it but what do its findings tell you?


Anybody know if these carbs have tuning screws? (I wont see it till Friday)

lol was that too long a post?

[quote name='110Anthony400']lol was that too long a post?/QUOTE]

haha ok fine... i guess the only thing i need to know is.... if it runs better with the choke on do i just need to get bigger jets? and where can i get em?

im goin to the lake 2night so ill be able to check it out

First off...you are going to have to decide on what filters you are going to run before jetting.  If it needs the choke 'tweeked' to run at high revs then you should jet up from what is in it.  
Try Denis Kirk...should have what you need, or when you get the motor, pull a jet and measure its length and your local shop should be able to scource them.

anybody know where to get a pdf service manual of this sled (97 yamaha 600sx)? thanks

http://www.pacificcoastmanuals.com/

ok sounds good, bringing the jets and air filter situation to the dealer tomorrow. good manual link

The best thing to do would be to clean the carbs first if you haven't, there could be something stuck in a pilot jet which would make it run better with the choke on.  I would think if anything you would have to lean it out since it will be used in warmer weather, even with a less restrictive filter.  If everything looks clean though, yes, come down in jet sizes.  Start with the main jet and work your way down.

i took the jets out today and brought them to a dealer. they were clean. i found out that

stock pilot jet is 45 and main jet is 151.3.
and the motor had in it a 30 pilot and 151.3 main.
the dealer told me i should get the stock pilot jet and a 155 and/or 160 main jet.
i didnt order them yet though till i found out what you guys thought.

Going up in jet sizes won't hurt anything, and if you think its running lean, then it needs to happen.  Do a little research on properly tuning carbs if you are a little unsure about where to go from here.  I think this article explains it pretty well:

http://www.dansmc.com/carbs2.htm

And this is one of the best, in depth carb tuning handbooks out there and is always good to have around the shop:
http://www.aaenperfo...m/Handbooks.asp

realized you need to go down in sizes for warmer weather. stock is 45 pilot and 151.3 main. it had a stock main so i got 150s to try. and the pilot in it was a 30 which is smaller than stock, but probably too much. i ordered a stock pair which im waiting for to try first.

got stock jets.... they were way too boggy, but ill have em for winter now. im ordering smaller ones tomorrow. i did drive it though. its idled good and starts first pull. i also got some nice wire mesh cone filters on ebay for 8 bucks each

This appears to be a twin cylinder,  not the triple that was in the later model SX,  I don't know what some of the guys are talking about with the red head,  which was on the the triples.   I believe Yahama only made that from 94 through 96,  you can get all the info you need on jetting at Totallyamaha