help with engine stuttering

[Berserker]

Hello,

I uncorked my xr650r two weeks ago (everything except pipe which is on backorder) and rode it that weekend without any issues. Tons of power - real scary sometimes.

Yesterday I installed a trailtech computer and took it out for a spin - bike was hesitating at the barest turn of the throttle but even worse it was stuttering at constant speed.

I'm open to suggestions on where to look. I'm using a 175, a 68S and a jet needle set. The parts were bought on ebay (http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=4540129139&category=35597)

Thanks for any assistance!

[JackAttack]

I'm open to suggestions on where to look.

Look and see if the choke is partially on. ?

?

[Berserker]

I wish it were so easy - unfortunately it's not. That was the first thing that I checked.

[JackAttack]

Did it go back to running fine after you disconnected the TrailTech?

?

Is your TrailTech mounting hardware interfering with the manual decomp hardware?

From your sig it looks like you have a 03 650, have you ever changed the plug? ?

[Berserker]

The Trailtech is not interferring with it though that is a good question. I had originally moved the levers out a little on the bar and found that If I made a right turn it was opening the manual decomp and stalling the bike. Fixed that though.

It is an 03 but it's a new 03. I bought it from the dealer showroom 4 weeks ago. I don't think that it's the plug. Can having the stock exhaust with the other mods have destroyed the plug already? I put about 4 hours on the bike with the jetting and stock pipe.

[frankstr]

Stock Exhaust, Maybe its to chocked up on the ex end... ?

Your getting more in but its not flowing out....

[JackAttack]

The Trailtech is not interferring with it though that is a good question. I had originally moved the levers out a little on the bar and found that If I made a right turn it was opening the manual decomp and stalling the bike. Fixed that though..

?

It is an 03 but it's a new 03. I bought it from the dealer showroom 4 weeks ago. I don't think that it's the plug. Can having the stock exhaust with the other mods have destroyed the plug already? I put about 4 hours on the bike with the jetting and stock pipe.

That will not ruin the plug.

If it ran good once with that set-up it should be fine now.

If the only thing you messed with was the handlebar controls, you should maybe check the kill-switch.

You could try to pull the baffle from the pipe and run it for a while. ?

[Berserker]

Sort of like a potatoe in the tail pipe eh? The thing is why did it work so well the first time out but now it hesitates even with constant throttle at 10mph? I was wondering about the air mixture, etc.....

[frankstr]

Pull the spark plug it probly is all sooted up........ ?

[Berserker]

Well, Pulled the plug on it last night - looks clean. cleaned it anyhow and put it back in. Tested it but no luck. The hesitation and stuttering is still there. ?

[roadcam]

this probably sounds lame, but is there any chance you got a dose of bad gas ?

[TimBrp]

4 strokes can be very finicky when it comes to jetting. Fart near em' and it could throw it all off. What clip position is your needle in? Should be the 3rd. Secondly pull out the pilot and clean it(it sounds clogged) and compare the emulsion holes on the supposed "68s" you purchased with your original 65s. Make sure the hole sizes are the same, not similar, the same. Get the exhaust HRC tip soon.... Finally have you pulled the airbox restrictions out yet? All this added gas and zero increase in airflow in or out would cause a rich condition and give you some sputtering.