just bought a new 05 660r se it was pretty fast,but i was kinda disappointed.I kept thinking I @#$%&! up should of bought the 700.Wellafter reading this forum(very helpful byetheway) I bought the yoshi,pro-flow,and dyno stage 2 followed the instructions to a tee.cut up the snorkle,box,lid,etc.Cut two 1 1/2 holes in lid, jetted like the dyno instructions said 144L-146R (4000ft.).Started it up.Idled perfect.Before mods right out of yamaha ran rough at low rpm.You would just give it a little throttle in neutral and it would sputter then kick in to like 4500 rpm and in 1st barely moving give it a little gas and it would bog.Anyways after I started it up with mods first thing I did was barely give it a little gas I new right away that problem was solved.On to the test ride.Drove up my 1/4 mile dirt driveway kinda going slow (keep the dust down) was kinda skeptical the way it sounded and felt but no more bogging low rpm.Got out the street punched it and instantly scrapping wheeli bar...holy crap!This thing only has 10 hrs on it ,stock barely wheelied unless you stand up,now in 1st just punch it and instant wheeli(comes up scary fast).Got my stuff back together cruise through 1st till the end punch it(wheeli),shift to 2nd punch it (wheeli) have to let off,punch it shift to 3rd litlle wheeli, haul butt through rest of gears.Bottom line this thing is way faster.One thing someone here might be able to help me with.It runs good from bottom to top but I noticed it was popping while coasting with no throttle in gear(more in lower gears) could this be my pilot should I go to 25 (114dn-146dn).Any feed back would be appreciated.

 

Did you richen up the Idle air fuel mixture screws. They are probably the problem.

 

yeah three turns out,the yoshi pipe instructions said 1 1/2 but that didnt seem enough from what I know dyno said 3 with the mods I got so I went with that.yoshi said the pipe should turn brown.It did mostly but up at the headers its a little blue

 

The yoshi pipe likes to pop on deceleration, mine does it running down hill and sometimes on the flats. I'm running 160/165, 25, 2.5/2.75 with no airbox, K&N with outerwears, sea level. When I was at 22.5 on the pilot, I was blowing carb boots off, I opted to go 25, could have just uped the idle and that problem would have been solved. I wouldn't worry too much about the popping, now if it's popping on acceleration, you're too lean, bogging down, you're too fat.

 

I have a Z400 (and recently bought a Raptor) and last year we went from Fillmore to Richfield (5000 to over 9000 feet back down to 5000). Once we approached about 7000 feet (I have an altimeter on my watch) I started to notice a difference. Once we were over 8000 it the Z would pop and backfire on deceleration since it was running so rich. When I would run at the dunes (about 5000 feet) I could tell it was still running a little rich and would get the occasional pop on deceleration. I put a full yoshi pipe, dynojet, K&N proflow and no airbox lid recently (it woke the Z up pretty good too) and jetted to the Dynojet kit recommendation for that setup and my elevation and I haven't had any probs at all - no pop, cough, backfire or anything and very quick throttle response, no loss of power at any rpm so I'm guessing you might still be just a hair rich. I would first try adjusting the air fuel mixture screw a half turn at a time and then go test it out for a while each time you adjust the screw.