robcassels

Thank you, Do you have a part number and/or first hand knowledge of the dimensions of this model's part? I will try to research that part as well.

Thank you for the information. I grabbed a pair of calipers from work and you are correct, the new parts (2NX-12159-00-00) are 6MM. However, the current screw in my bike does measure out at 7MM (6.9342MM exact). The locking nut has an inside dimension of 6.223 MM. Any suggestions as to referencing the various Yamaha Valve Adjustment screws to their respectives sizes. Even a phone number to an actual Yamaha dealer anywhere in the States that may have a hardware reference manual. I have called several "Yamaha" dealers in florida but they are all multi brand dealers that only have access to the standard mirofiche files that we all have seen. Any help would be greatly appreciated as the busted adjustment screw is slowly wearing down thought the threads now, the compression nub is what has broken off. I ride the bike every day to work and have to re-adjust the valve screw every 40-50 miles. I would like to avoid replacing the rocker arms as I don't have the time right now to rebuild the top end nor the funds and I depend on the bike to get to work. Thanks

Hello all, I have a '81 SR250 with a busted valve adjusting screw. Having a bit of a problem finding the correct size. All the microfiche images call out a # 3Y1-12159-00-00 which has been superceeded by # 2NX-12159-00-00. I have ordered both of these numbers from the internet and received a part which has a diameter of 5MM and a 0.75 thread pitch. However in my bike is a 7MM with a 0.75 thread pitch. I can find nowhere on the net that describes the dimensions of these parts. My assumption is that somtime in the past a previous owner must have put an alternate set of rocker arms in the top of this motor for whatever reason. Does anyone out there have some reference to the size specifications of yamaha valve adjusting screw parts so I can match up a part number to the measured size and order them? Thanks for any help you can give.

Name: Yamaha SR250 (1981) Date Added: 18 December 2012 - 02:47 PM Owner: robcassels Short Description: None Provided View Vehicle