littlebitcrazy Posted August 9, 2011 #1 Posted August 9, 2011 The website i found list the style of main-jet that is needed http://www.pjmotorsports.com/street-bikes-fitment-list.html (bottom of page). But does not list the style of pilot-jet that is needed. http://www.pjmotorsports.com/mikuni-jets.html#piolot/slow%20jets I don't want to have to tear my bike down just to see what parts i have to buy. I'm riding an 07 RSTD Any information would be greatly appreciated.
Carbon_One Posted August 9, 2011 #2 Posted August 9, 2011 Perhaps you overlooked it but the 1st link listing the Yamaha jet fitments does say main jets as being Mikuni N102/221. Mains are the small round head types. Using your 2nd link that would be the 4th set of mains down the page shown. I measured extra mains I have here at the house to also verify the size/type. Keep in mind that each cylinder has a different sized main. #1 & #3 being larger. Been a while since I've been into the carbs so don't remember the exact #'s used per cyclinder. Larry
dingy Posted August 9, 2011 #3 Posted August 9, 2011 It looks like #1 & #2 mains are a 122.5 #3 main is a 117.5 #4 main is a 120 Trust, but Verify I would be interested in logic behind these. I can see a front to rear difference possibly due to heat, but what about side to side difference? Gary
littlebitcrazy Posted August 9, 2011 Author #4 Posted August 9, 2011 (edited) I did find the main jets. My question was what style of pilot-jets do i use? I want to up the main and pilot jets by one size I got this info from a thread on this site I am gonna buy 2 #125 main jet for Cylinders #1 and #2 and 4 # 17.5 Pilot Jets. I am gonna reuse the jets i already have for Cylinders #3 and #4. Cylinder #1 and #2 will use the #125 jets that i buy Cylinder #3 I will reuse the #120 jet from cylinder #4 Cylinder #4 I will reuse the one of the #122.5 jets And im going from a #15 Pilot-jets to #17.5 Pilot-jets Edited August 9, 2011 by littlebitcrazy
Carbon_One Posted August 9, 2011 #5 Posted August 9, 2011 OOPs my mistake in reading it all. Ok you need the N224.103 pilot jets. I did what you're planing on doing several years ago. Bumping all pilots & mains up 1 #. I found that bumping up pilots was very helpfull in low end & inital throttle response. As for the mains they were running to rich causing the spark plugs to turn black. Also at times under a load pulling a trailer I was getting black exhaust soot on the cooler. Once I changed back the mains to their orginal postions my spark plugs were once again a nice clean brown/tan on the tips. No more problems with exhaust soot either. I did leave the pilots bumped up one number. At the time I was using H-D mufflers but that was the only change from stock. I'm now back with shortened stock mufflers since converting to a trike. Good luck doing you mods and let us know what your results are. Larry
littlebitcrazy Posted August 10, 2011 Author #6 Posted August 10, 2011 This site never disappoints!!! Thanks for the help.
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