300/440/550 carb

[the flying dutchman]

also what is the best carb to put on a 550sx, and were can they be bought at rather than a used one,, thanks

 

[Austin]

I like the 42sbn on the 550 with a pipe and a head. I have a few friends with 550's and one runs the 42 and the other runs a stock 38 off a x2. It might also depend on what other parts you have because a stock 550 would need no more than a 38 and maybe 42 but that is pushing it.

 

[the flying dutchman]

my ski is a 90 550sx pp and its bored over all the way factory brand pipe west coast water box and pjs head, have all the other gooies downstairs in her to, but it does have a diff carb but it gives me problems and im not sure what it really is it has the vestport filter on top. how can i tell what it is?

also were would i get new carbs at? thanks

 

[Austin]

With your set up I would go with a 44sbn or 42sbn witch ever you can find. Ther is a local shop in my town that I can get that stuff from so I would check if there are any shops in your area first if not then I would hit up ebay (good deals).

 

[the flying dutchman]

so i know that it is the mekuni with the vestports filer but is it stocl or what? and a local shop or e bay would be best place to find a carb or a shop any new i can find?

 

[Austin]

It is not stock if its a mikuni if it was stock it would be a keilin. You are probably running a 44 I bet they are very common. I would search up the side of it first but I am guessing it is a sbn (the side of the carb will tell you the model). Just go on line and get a rebuild kit. I would tear it apart and and blow out the jets and put the whole rebuild kit in it. I would do that before spending 300 to 600 on a brand new carb. I Have a 44sbn on my x2 and it was running ruff then I did the whole rebuild on it and it runs great so I would start there.

 

[the flying dutchman]

ok man thanks! but that is the only thing it runs great there is no problem with it running but i cannot use my choke the only thing that is does is it could b the first ride of the day or ive been riding for 4 hours and shut it off it takes forever to start and i have to hold the throttle wide open? any help

 

[screaming440]

as far as stock goes 550s came with a 44mm mikuni carb after 85 when they went to the 1/2 pipe style exhaust. a 38mm mikuni would be on a 440 0r older 550 and keihin's where used on 650s.

we have used the 44s on a lot of really fast 40's and 50's and they work fine.

as for the hardstarting this is a problem commonly caused by crank seals. if they have not been replaced recenly its a good idea to do it so your not chasing your tail.

 

[the flying dutchman]

also on the side of my carb its like a milkey water or something there like gas and water is mixing and blowing out.. ive tryed to let it run with the hood off but cant see were it is coming from.

any ideas would be great if it would help i will try to upload a pic but have no clue really how to do that. but i havent been runing the ski afraid maby this might be the result of a cracked block?

 

[cookn]

That is a fuel water mix on your carb. My guess is its coming from a leaky diaphragm. It could also be leaking from a worn out throttle shaft. Im pretty sure a carb rebuild would fix this.

 

[Ĥölënböt]

reed 550sx came with a 38 keihin
90sx is a pp and came with 44bn and the jetpower ("half pipe style") pipe that became the norm for 550's in '85
a 44 sbn would be perfect look on ebay but plz dont pay the 300-400 some people are asking for them

to run the 44 sbn you will also need a mani for it or a spacer the carb will hit the cyl its a little bigger than the bn thats on ur ski now

make sure you have the fuel in/ret lines hoseclamped to kep them from leaking

 

[gtgoat]

What is a good price to pay for used SBN44?