My buddies 2004 YFZ LE(on my pic page) cuts out and misses on WOT. He took it back to the dealer and they tinkered with it, told him to keep his headlights on and it would be fine. He gets it home and it still does it. So we put a Alba pipe on it...put on a K&N filter...change the needle, pilot's and mains. We put a 165 main in...too lean....so we put a 170 main in...still to lean....we put a 175 main in and now we are getting a good plug color but the misses and sputters on top end are bad...really bad.

They were bad when he took it in the first time...he started running the headlights and they were still present....put the pipe on and change the jetting and it still happens. If you just casually ride about 1/2 throttle it doesn't do it. But when you start getting on it, 4th and 5th gear sputter horribly. Any idea on what the problem could be?

Should my buddy just take it back to the dealership and drop it off for another 3-5 days for them to screw with it or what? The bike is about 1 1/2 months old. Maybe 10hrs on it. If that. It's already had one service.

 

No one care to guess?

 

My friend got HMF and he run about 180 main jet.... You might want to try in that general area.....imo

 

I used a 180 main also. try it and see. If not, take it back to the dealer!!

 

I'd take it back to the dealer and tell him maybe his 'ol ladies headlights would work better !
Other than that fix it !