carb help

[ninjamonkey_16]

hi, i dont really know anything about carburetors, like the jetting or what the jets are. can somebody help out? i dont know what jets to change depending on temperature, rpm range, etc. im just curious about cabr setup and the sizes of the jets. also, can i adjust the mixture screw on the side of the carb (mikuni) if my bike is bogging in a certain rpm range, or will that ruin a piston or what have you. i dont want to melt a hole in mine like a friend of mine did.

[TRexRacing]

OK here is something to help you along.It's for Mikuni carbs but theory is the same on all.

[Only registered and activated users can see links. ]

What symptoms are you having?Or are you looking to tune the bike to it's best?

[ninjamonkey_16]

well its actually on my lt230, but i dont think it would matter.
basically, whenever i try to give it throttle, it bogs way down like im drowning it, and the air/fuel screw is out as far as it can go so i was just wondering if i turned it in if it would make the bog go away, or at least lessen it.

great link by the way, it helps a lot, thanks

[TRexRacing]

What ratio are you mixing the fuel/oil at?Is the bike stock?Or does it have a pipe?

[ninjamonkey_16]

straight gas, stock, stock pipe, and i turned the screw two turns in and it went away, so thanks anyway.

[Willum]

I just went through the same problem with my yz250. I thought it was jetting but it turned out to be leaky crank seals. First I would take the Carb off and clean it and see if it helps. If not then I would check for air leaks. Head gasket/base gasket and then lower end seals. When I took my stator off the seal was hanging out of the case just sucking air in. Good luck