Staggered jetting and some other questions

[zore]

Can someone explain to me why Yamaha staggered the getting from front to rear?  And can someone confirm for me that the front is a 122.5 and the rear is a 127.5.  Seems like a lot of stager.  I've also read that a few of you are using the same gets for both front and rear.  I was talking to a bike mechanic about the staggered jetting as Yamaha isn't the only one to have done this, but he couldn't give me a real reason why.  To me, it would make sense that 2 cyl of same size, with the same carboration, should require the same amount of fuel/air.  I have been told by another mechanic that the relation of Jupiter with the earths moon can change jetting in a Vision.  I think my plan is going to be to buy jet sizes ranging from 118 to 132 and just take it to a dyno.  Or maybe buy one of those k&n gas analyzers. 

I also am curious, what is the recommended valve service interval on these?  And can I ignore it like I do the ducati valve check interval?  Does it really have valves or some electronic magical force that mixes the gas and air together.  Why am I spending my mothers day morning on the ROV forum while my beloved wife toils with the screaming children?  Because I'm this guy...



Happy mothers day everyone.  Take your wives out to breakfast or something, then stick a beer can to your head.  It really is more fun than it looks.

I know I'm hijacking my own thread, but I thought this was worthy to post since I worked really hard on this (3 minutes at least).  I'm sure you most have you have read the story I told of the guy in our group who passed the car on the gap, in the rain, over a double yellow, then threw the bike over the side of a cliff.  Well, I have warned all in our group what happens when you wad a bike up doing something stupid.

[Lucky]

what scares me is that you had the foretought to take a pic like that KNOWING you'd be photoshoping it later....
the jettings different because the exhaust length is different.

[h2olawyer]

Owner's Manual says to check the valve clearance every 5,000 miles.

:D "And I thought the Woodchuck Cider was so Butch!"  :D

H₂O

[QBS]

V valve clearances hold seemingly forever.  I have had my valves set approx. every 30K miles whether they need it or not.  In the 22 years and approx. 85k miles I've own my '83, I think the valves have been adjusted maybe 3 times.  Everytime my mechanic has reported virtually no adjustment was nessessary.