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  1. #1

    GP800X Carb Problem/Upgrade Question

    Hi everyone.

    So I have an 99 800 that i got from a mate about a year ago, wasnt working at the time. Has barely been on the water and have spent much time and a few $ fixing and replacing things, but will skip to keep the story short.

    Have had it running, and it has been having some type of fuel issue. It would bog when coming off-idle, when it decides to go, it goes, but most of the time i just keep throttling and it dies. Doesnt stall on throttle, but just bogs.

    Working on it last night i found what appeared to be a small fuel leak, and after further inspection today i found where it was coming from. Looking at the carb directly towards the throat, airbox off, from the right side of the ski. On the left side of the right carb,(so in the middle of the 2) there is the plate held on by 4 screws. In this plate there is a small hole, and at certain points during throttle i see a bubble and fuel come out of it. I looked at the other carb, different plate on it but same hole in same spot, so i assume this is normal and is a breather of some type?

    I guess im just looking for confirmation of the fact the carb is buggered, and fuel is leaking somewhere inside and then finding its way out of this little hole and down the side of the carb. A mate suggested plugging the hole up with some metal putty, but i expect the hole is there for a purpose.

    2nd part. I have done a lot of reading/research last couple days, and seems to be many opinions these carbs are pretty average so im looking to upgrade rather than rebuild them. Big reason for this is i can get a set of 'Mikuni twin SBN48 Buckshot carbs' which have just been rebuilt, and including twin air filters, for $200.

    My biggest concern is whether these are just way too big, and what issues i might have with them. Im pretty keen to just grab them, cost wise they seem by far the best option, but if they wont work then theres no point.

    Any and all opinions appreciated. Cheers


  2. #2
    To big for that engine. The stockers are perfectly fine until you go major big bore. Rebuild the ones you have.

  3. #3
    But is there a way to make it work? I dont know exactly what this ski has, im new to skis. engine wise i think its stock, but im also looking to put a high compression head on

    For 2 rebuild kits, new needles/seats/springs(low end bog i want to fix) and shipping to me(australia) im looking at $150 or so. whereas $200 i can have 2 48mm newly rebuilt buckshots with flame arrestors... it seems worth finding a way to make it work

  4. #4
    A child of five would understand this. Go get one. pierowman's Avatar
    Join Date
    Sep 2011
    Seattle, WA
    Not sure about the buckshots but sounds like you might spend more than $200 trying to make those carbs work. Where rebuild and needles are a known solution that works and is reliable. Just my .02

  5. #5
    I dont mind spending a bit extra if there is far more value in it, if you follow what i mean. The cost for new 44s that i can find on are 200 each, plus shipping. So if buckshots+filters cost me 200, and another 100 to get them working, im still way ahead.

    Are we talking about redoing jet sizes, or is there more to it than that? The carbs are a 46mm that have been bored out, if that makes any difference, but i didnt think so.

    The other option is i just buy all his gear coming off the 800, buckshots, hi comp head, twin pipes, cdi...but im trying to not go that far with it, but its tempting lol

  6. #6
    A child of five would understand this. Go get one. pierowman's Avatar
    Join Date
    Sep 2011
    Seattle, WA
    I get what your saying but if your plan is just to keep the ski stock then going to bigger carbs arent going to help anything. Its not like the stock carbs cant push through enough fuel obviously with jet change. The problem i forsee is that your fuel requirements are going to be much less than what the new carbs will want to give. So youll need to turn them down and getting them to the sweet spot is going to be difficuilt because it wasnt designed for that fuel flow, it may get finiky where just a hair adjustment gets u to much or to little fuel. But hey man its your ski. ultimatly your the one that has to deal with the install and adjustment.

    I was just pointing out that your pain will be less with the current carbs vs bigger carbs and stock setup that no one is running. Not to say it cant be done.

    The stock carbs would want a rebuild, new jets, possibly springs, the t-handles are a must, and flame arrestors. Make sure D-plate is installed. Thats going to push $200 on stock carbs.

  7. #7
    Yeah im sticking with rebuilding the stock carbs. Thanks for the reply.

    Wth is a D plate tho? Back to searching...

  8. #8
    Im in australia, so i think im good on the d plate front, the cat is a US only thing if i read correctly?

  9. #9
    Ok so i have a high speed adjuster stuck hard on one carb, and a low speed adjuster stuck hard on the other carb... options?

  10. #10
    1200Jet's Avatar
    Join Date
    Nov 2009
    Stick it in the oven and get it nice and hot (all fuel removed and wife out for the day) put some gloves on and attack it with a screwdriver till it gives.

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