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Thread: need for speed

  1. #1

    need for speed

    i am in need of some low buck performance mods for my 91 650sx its stock except someone removed the waterbox. im pretty green on pwc but mechanically inclined. the wife has a seadoo 580 spi and walks away from me! i need help!

  2. #2

    Join Date
    Jul 2007
    Smithtown Long island
    try getting a new prop

  3. #3
    thesepaperwings's Avatar
    Join Date
    May 2007
    South East Kansas
    I'd say a waterbox, f/a's, westcost exhaust manifold and pipe, intake grate, r&d nozzle, heads, impeller, rideplate, stator. All those you can prob find used on ebay because of the age of your ski. If you want to go crazy, bigbore, flat top pistons, lighted driveshaft, duel carb setup. It would be one sick 650

  4. #4

    Join Date
    Jul 2007
    Puerto Rico
    try this......
    1:solas 13-18 impeller
    2:mikuni SBN 44 or 46 carb, ill provide u the jetting number that have worked for me.
    3:mill your head to 175 psi. ( do this if your skis comp is good).
    4.remove the reed cages and flip them over ( this is the easy way to make them seal completely.
    5. remove oil pump and go pre mix
    6. remove water drain and do the block off.
    7. water box for your ski (see what u find)....
    8. coffmans exhaust if found.....

    this should put your ski between 47-50 mph. depending on rider skill and weight. minor porting/polishing on intake exhaust, cylinder port matching(mild porting) should give you 2-3 extra miles you will still be under 53mph.
    magnum pump, of extrude honing pump, milled pump cone (another 1-3).
    TDR medium carbon flappers (greater engine response, Low-mid).
    Hours and hours of finessing the carb will give ya more reliability and some extra speed. Similar setup was used on my 1989 650 when it was rebuilt completely and I was able to obtain close to 52 mph (I weighted 195 at the time). a lighter rider Tony doukas Wife was able to obtain 54.7 as indicated by a stalker radar. tested at sea, no chopped waters, 6pm on a relatively cool day for Puerto Rico. The setup at the time was std wiseco prolite pistons, crankshaft trued, pinned, welded and balanced and msd enhancer with red blaster coil....... Long story short skis was sold on 1996 and fell on my hands on 06/2007 as a piece of junk (restoring this craft as we speak).
    You see you will run big bucks to make your machine faster, any way you will need many of this parts if you decide to go 750 or 800 swap.....which I would do 1-7 on the list this should not set you back finantially and you will have fun with the 580.....
    Most important thing is tell you wife to try and do a sub dive on have a fun machine she and mostly all other sitdown rider would never understand the fun of riding a stand up. They are always mouth wide open trying to figure out why would we go to the trouble on riding these machines.... For me there is no such thing as of let me try this....or can I ride it, answer is Hell no, try a seadoo.....hahahhahaah

  5. #5

    Join Date
    Jul 2007
    Puerto Rico
    as promised seat valve on the sbn mikuni 44/46 is a 2.5 spring on seat valve is a 115 grams to prevent flooding. no filter installed.
    Hi needle is a 160, low needle cant read but it should be a 85 or 95(not sure).

    Carb was built by scrapping a few togheter and a new carb kit to go with It was under 100 to build it and rebuild.

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