As the title says pretty much. I know the 3LN and 2KR carbs are different, but are they interchangeable between bikes? Mines a 2KR and i'm looking for a genuine butterfly valve if I can, but its more likely i'll find a complete set of carbies and just curious if I do find ones in better cond to mine if I can swap the whole assembly over Alternatively does anyone know if the throttle body diameter and shape is the same? Since all I really need is 1 butterfly valve
@GreyImport is best placed to impart his wisdom on this topic, if not possibly @maelstrom. I think 3LN1+'s are interchangeable (the newer carbies are slightly different in design) but I'm not sure about the 2KR.
Actually for the 2KR they are BDS26. It is most unlikely that the butterfly from the 2KR would fit the later model. Fitting BDS26 carbs to a later model will require that the rubbers on both sides of the carbs can make an effective seal and that the carburettor centrelines are the same. If the homemade butterfly that you made is sealing correctly then there are three issues to consider for poor low speed running. Setting of the pilot mixture screws. Do not expect 'n' turns out to be correct. Worn needles and/or emulsion tubes throttle opening balance If it is of any use, if I had to make a butterfly I would have scribed the outline using an original part and then drilled out a rough outline then file and sand to finish. cheers Blair
The one I made starts from a waterjet cut template. It's starting point is much closer than you'll get from cutting it out by hand. And it is 95% of the way there, but it is slightly uneven at very small throttle openings. It's an incredibly time consuming process filing off hundredths of a millimeter at a time. Now i'm fairly happy with it as is but I don't mind spending a small amount on replacement carbs if they're cheap enough. So I guess 3LN carbs are completely out of the question then
Just gumtree it dude, should be able to pick up a set of carbies for a 2KR for $50-$100. There's a few around, try: http://www.gumtree.com.au/s-launceston/yamaha+fzr250/k0l3000393
Those are some pretty rough looking carbs.... I ended up getting another set for the butterfly valve, not a bad idea that I did because I swapped over the diaphragms as well which got rid of the 'notch' in the slides when pushing them up quickly, which is caused by the diaphragm being slightly swollen and folding over itself as the slide rises I figured the carbs would be more expensive but I didn't spend all that much, if I knew they could be had in the $100-200 range I would have done that originally. My experience with carbs is on dirt bikes, where it's common to pay $450+ for a 'single' second hand carb
