03 cr 250 running poorly please help
Posted 30 May 2012 - 09:04 PM
redid top end new cylinder, new top end, with pro x piston, cleaned the power valves, cleaned carb up.
i broke in the top end and have goten a chance to ride it, not hard but it doesnt do anything but bog down at anything more than 25 percent throttle and along with the bogging it smokes what seems to be very excessive, as well as that it has a large amount of black spooge coming from the silencer to expansion chamber. i have not left 3rd gear yet but when your just lightly on the throttle it seems responsive and you could throw a wheelie but if you try to get on it suddenly there is zero power just get smokeyer.
i should also state the bike did this when i purchased it i got a good deal thinking it was just a burned up top end, wich it was the cylinder had a crack in it and needed a top end so i replaced all of it, now the problem continues.
i pulled rc vavle cover off and it looks like they are working ok the move when i give it throttle. i have not played with the jetting or the idle mixture screw, there is a second screw on the carb a philips im not sure what it does all just yet.
i do not think its clutch slippage as it does this in idle as well, if i rap on the throttle when in neutral it will bog down not rev up, im wondering if the power vavles need adjusting or is this a terrbile problem due to jetting,
please help !!
Posted 30 May 2012 - 09:47 PM
Mostly sounds like gooed up carb.complete rebuild or replaced completely with a Keihin PWK38 that all the guys in-the know on these threads will explain to you. After I completely changed over to the PWK off a 2006 YZ250 to my 2007 CR I got in a hurry and did'nt pay attention to what carb. I was dealin with and accidently left out the main jet and pilot..(I made sure all was right but I was looking at the carb I took off by mistake and thought the PWK was ready to go) It started 1st kick but ran exactly like you described SPOOGE...RICH>>COUGHHHH...Get that info and someone will surely figure it out probably faster than I can surely type Ha!!!!
Posted 30 May 2012 - 10:04 PM
Posted 30 May 2012 - 10:06 PM
does it have a nut on the outside of it locking it in place? mikuni carbs have a setup like that which controls the idle.
have you checked for intake leaks and really inspected the reeds for cracks?
Edited by schrode, 30 May 2012 - 10:07 PM.
Posted 30 May 2012 - 10:50 PM
only rode it when i bought it and it ran like this, i wanted to start with the basics so i bought a new cylinder and top end rebuild kit, there was a crack in the power valve brigde in the cylinder wich is why i bought a new one.
i am wondering if possibly some re jetting and idle mixture screw mite help but this seems to be a very extreme case unless the jetting is just completly rediculous, truthfully i rebuilt the carb but didnt think to check what the sizes where i was planning on rejetting it so i didnt bother. but i have never seen jetting take this much of a tole.
i was going to start buy getting the recomended jett off the fmf website for the pipe i have on the bike
Posted 30 May 2012 - 10:58 PM
Posted 30 May 2012 - 11:06 PM