[xridgerider]

Current setup: 05 250x with a brand new 07 R head, new 05 R cam, new R pipe, JD Jet kit, red needle in the middle, 155 main, Pretty much all CCC mods done. Went to fire it up for the first time after rebuild and it started right up and sounded great but the header pipe started to smoke and got hot very quickly. I only ran it long enough to turn the choke off and shut it down. So I am trying to get a clue on how I will tune her. I was told it is running way too lean now that I have all the R stuff. I was also told by a reputable source I will need the R needle and possibly a 170 main? What are your thoughts? Any help would be great with this rebuild experience. I live in Idaho and ride mostly above 5K. Thanks...

[jjrace]

you have a JD jet kit. Contact JD about the changes, I am sure he will get you on the right track.

[Asmith]

Try setting the needle to the 5th clip down and run a 162 or 165 main.

42 pilot jet and set the fuel screw to 2 turns out.

[xridgerider]

I installed the 165 main, still have stock pilot installed. Fired the bike up and it started right up, ran it around the block and stopped. The exhaust pipe was smoking this time and did for awhile, but header was not. Maybe that new R pipe packing and silicone? Smelled hot, motor was hot, and it died as soon as I let off the throttle. Not sure where to go from here, could it be any of the exhaust valve clearances or timing? Any help or suggestions would be great. Thanks... going to proceed with a 170 main and see what results I get from that.

[Codeman00]

If you just installed a new 250R exhaust, it can smolder for awhile but that doesn't mean that your jetting is incorrect. I tore out the packing and put the spark arrestor on my new R exhaust and the pipe smoldered after the first few runs. I don't know what was on fire but there was some debris that it self cleaned

AS's recommendations are right on...You need to move up to a 42 pilot and a red needle 5th position, that's for sure. You know that pilot controls the low throttle running and the main controls the high RPM running right? I'm not sure you need to go with a 170 main yet...you should be close enough already.

There is a proper procedure on jetting...its impossible to help when we don't know details of your run....all we know is that you ran your bike and it got hot Were you running full throttle, half throttle, etc? What is your idle set at, etc? Have you adjusted a fuel screw? This is critical to where it is set.

[xridgerider]

It started getting hot and smoking just half throttle or so around the block and sitting on the stand. Brand new topend so nothing wide open. Today I started pulling the carb off again to double check things in the carb. I hate that plastic hot start screw! I know I will find it..could be a air leak somewhere too. What is the stock x pilot jet? I am betting that needs to be changed too. She doesn't want to stay idling either. Not sure about the idle, it was x stock. Full screw is at 2 turns out. Also a question for the board. I didn't use a new header pipe copper seal ring, it was slightly beat up but looked usable so I am second quessing getting a new one of those too. would that have an effect? air leak? Pulled the plug and it looks LEAN. Any suggestions would be great...I'll keep this updated on what I find.