The idle is mostly controlled through the pilot jet (dont see where you said what size jet you have installed) as well as the idle mix screw on the right side of the carb.  The needle jet and accompanying spacers are responsible for mid range throttle performance and the main jet is for upper level of throttle performance.  Tweaking of the pilot jet and idle mix screw can usually fix most if not all idle problems.  Hope this helps and read some of the carb tuning threads in the tech. section.

-matt

matt_savage wrote on 04/09/09 at 12:35:37:


Matt, were there a Nobel Prize awarded for Motorcycle Forum Responses, you'd get my vote.  That was right on the money!

DJ,

It's amazing what a little research/reading past posts will do knowledge wise!  I've only been working on my bike myself for about 2 months!  I've just re-jetted my own carb but have yet to get it back to the point where I can fine tune it while running.  

new guy,

-best advise I can give it to go out and tweak it till you turn purple, literally.  And read up and ask questions in the meantime.  Only a certain # of variables for the idle problems but you should be able to get it right where you need it.  HTH

-Matt

Sounds to me like you are still too rich.

Rough running ... rich
Warm up and it gets worse ... yep, too rich
Go back to the #52.5 pilot and readjust ... if you do not have a good one on hand I think I have one with me I can send, but will need to check ( I am visiting my daughter in NC for a couple of weeks).  It is possible to get backfires with a too rich condition, though not as common as a too lean condition.  Remember, backfiring is a result of umburned fuel collecting in the exhaust pipe and the igniting later when heat and O2 are added.

Using a  single washer on the needle is too much; I would suggest that you use 3 on it.  You will get clean responsive power with the correct setup for 1/4 to 3/4 throttle.  The responsiveness anywhere in that range should be quick and clean; no bogging or hesitation or shudder or coughing or etc etc .... just instant response, and if not then your setting is off.  
If it is too rich then it is sluggish, hesitant and/or bogging.

Same elevation here, and did the same mods with the Lancer kit, except I put three washers under the needle. I had the same problems you describe. i had to go back to the OEM 52.5 pilot to make it run right at idle again. At the same time the popping came back. No popping with bleeder 55 pilot, but awful running otherwise. I also had to pu the 145 main back in, because even with 150 main it was fouling the plug at WOT. It ran better if I backed off a tad from WOT. So this shows it's too rich. The only thing that REALLY improved the ride was rplacing the spacer with three of Lancer's washers. The thorttle response very clean, very quick, very accurate, seamless all the way up to WOT. Every little change to throttle position is very precise. The inside of the muffler gets grey on longer trips, darker in town on short trips. No bogging even in cold weather,even after pushing the choke back in after a few hundred feet. Idle screw is at 2 1/4 turns out.

You need to go back to the OEM pilot, and maybe at least down to the 150 main.

I had to mess with mine for a while cause I jumped in and did shotgun approach.  I should have done the one by one.

Lancer your input is always greatly appreciated knowing your experience with carbs. I will do as you mentioned regarding the pilot jet. I'm unsure of it's condition due to my lack of knowledge as to what I'm looking for exactly. I was originally going to go with 3 washers but I read here somewhere about complete removal close to sea level plus the smaller diameter #4 washers from the mechanic helped deter me also.

ralfyguy thanks for sharing your similar experience, a great help also. I was also thinking of dropping back to the 150 main just to see if it would help.

What's the quickest way to get the carb in and out for you guys? My K&N is getting pretty beat up from the squeezing and forcing! Thinking of pulling the battery box this time and lowering it down.

Jim, dasch, I'm hearing yas loud and clear. Total shot gun approach this round. Jumped right in with both feet, figured if I'm takin her down should take care of a few things all at the same time lol
Best way to learn though, the HARD WAY!!!!!  

So next change will be add 2 more #4 washers to the needle, swap 152.5 main for 150, and go back to the 52.5 pilot, readjust mix screw and report back to you all. I plan to get the work done over the weekend and will reinstall early next week.

Thanks again everyone. Dont know what I'd do without this site and you fellow members.