New guy on the block

1 reply to this topic
  • Littlefoot

Posted May 02, 2002 - 08:20 AM


This forum is great. I'm addicted, spent several nights searching, reading till 2 am. Just came off 1/4 midget racing with my Son. We had forums, but they turned into b**ch sessions and many perfomance enhancements became political secrets.

I'm a recent owner of a '99 WR400, haven't ridin it too much. This bike loves to flood. Typical Yamaha, rich from the factory just like their sleds. I will be ordering the assorted parts for de-octopusing, re-jetting and doing the APJ,(Taffy), mod.

Taffy and JD I'm in Michigan, USA, 0-500 ft., humid, cold winters, hot summers. Would either of your jetting specs. be a good baseline to start?
:) :D

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  • MN_Kevin

Posted May 02, 2002 - 08:33 AM


Rich in Orlando's jetting:

My 99 WR came with a 180 main and DTM needle. I thought it was so great...until I started leaning the bike out. Do you ever notice the top end just kind of die away and you stop accelerating? Pump the throttle and then it will speed up on top? That's what mine was doing until I went to a 160 MJ, 35 PJ, 55 PAJ, 160 MAJ, 60 SJ and EMM needle. The leaner configuration didn't cost much ($20?) and this thing gets going like never before. I didn't believe it until I did it for myself. And I'm going a bit leaner as the weather warms up. I recently dropped to from a 160 MJ to the 158 because the temps are in the low 90's these days. I'm also planning to screw in my PAJ screw to get rid of a little low-mid throttle vibration. (I think Taffy recommended the 45 PAJ setting. How many turns out is that again?)


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