48 pilot, 170 main: What about summer riding?

9 replies to this topic
  • mnm567

Posted February 01, 2006 - 09:06 AM


Hello fellow '06 owners,

Got to ride my bike for the first time indoors yesterday. probably 45 degrees inside at Motoplex, Fort Wayne. Same problems, popping, took me seventy kicks to get started. I had to back the fuel screw out almost three turns to get it to run decent. still popped So, 48 pilot, 170 Main. What will the bike do this summer when it is 75-90 degrees and extremely humid. I didn't have to do any jetting changes in the '05 from season to season. I would like to fix the '06's current jetting problems and not have to worry about it again, like the '05. So, is the 48,170 too rich for the hotter temps? Your input it is greatly appreciated. p.s. I didn't find this question in any other post. :thumbsup: Matt

  • mtrdrms

Posted February 01, 2006 - 09:19 AM


I had the same problem then I rejetted to the 170 48 and the bike started first kick. In my opinion this is not too rich and may even be still a bit lean. As far as changing it from season to season, you wont have to touch the jets but just play with the fuel screw a little to fine tune.


Posted February 01, 2006 - 09:24 AM


Matt I've been searching the forum for the almighty jetting fact book.I and alot of others would probably appreciate it if someone could put together a general set up for say every 20 Deg of temp based on Altitude.
Does the James Dean Jetting Guide accomplish this? Where you input temp and altitude and it gives you a set up for that temp?

Mike :thumbsup:

  • bg10459

Posted February 01, 2006 - 11:01 AM



Look at Indy's jetting post about 4 down from the top. Although it is for WR450's, it should give you an idea of the required changes for temp and altitude.

  • mnm567

Posted February 01, 2006 - 11:26 AM


I am just hoping there is a set-up that will work decent in all temps. Like mtrdrms said just turn the fuel screw to get it working. What I want to get away from is re-jetting the bike from season to season. If 48-170 does it, I am doing the job tomorrow. Thanks guys for all of the input. Matt

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Posted February 01, 2006 - 01:02 PM


Yea now that's what I'm talking about. :thumbsup:
I just got done rejetting YZ 450
JD Blue 4th
48 p
170 Main
Started with 1.5 turns out. There was a little studder off idle
gave her another .5 turn.
Next ride she was pulling the front tire off the ground in second with just
blipping the throttle. :thumbsup:

It was 44 deg 66% humidity.


  • Eddie Sisneros

Posted February 01, 2006 - 01:21 PM


you can leave it the same and it will run fine.if its really hot and humid lean the main jet to a 165.

  • gdbarr1976

Posted February 03, 2006 - 07:55 PM


Ask me that question in August. I have ridden in temps from mid 30 to mid 70s with no problem. 48 pilot 170 main. I think it will work year round.

  • mnm567

Posted February 04, 2006 - 05:37 AM


That's what I want to hear. It is hard to believe Yamaha would jet the bike from the factory so lean. It's pretty much the same motor from last year but the jetting is way different. Thanks, Matt

  • Ga426owner

Posted February 04, 2006 - 12:20 PM


Go to a 168 or a 165. :thumbsup:

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