[imlandwert]

ok so i just traded my 2000 cr125r for a non-running 2004 crf250r plus $500 a few days ago, the guy i got it from claimed he took it to a shop and they told him it needed a bottom end, so i tore it down and inspected the bottom end and there was no play/ movement on it at all, i then realized the piston was on backwards and the intake valves were hitting the piston, so i put the piston on the right way and put it all back together making sure the timing was correct and all that, well it wouldnt start, so i went to autozone and got some carb cleaner and cleaned the carb put it back on and it started but it was really really hard to start, harder then my dads 05 crf450r, also it wont hold an idle, i have to keep giving it gas or it dies, PLEASE HELP

[MattBennett23]

You probably need to clean out all of the jets really really well, or better yet, replace them completely. If the bike sat at all the are probably gummed up and not delivering your fuel properly. That would probably be the cheapest solution. I would also check the valve clearances and make sure everything is in spec.

[MattBennett23]

I guess I assume you were using the choke right? Maybe try turning your idle up some. Also, is it running smoothly when started or is rough and choppy?

[imlandwert]

yea when i cleaned the carb i cleaned all the jets really well, i think im gonna order a carb rebuild kit, and i was told maybe i need an accelerator pump, could that be true? and it wasnt running bad just wouldnt idle and it had a slight lag in throttle response, and i ordered a shim kit so i can re-shim

[crfsonly]

there could be several issues causing this hard starting. first, jets are very difficult to clean to new condition. the pilot jet in particular is difficult. i recommend replacing the pilot jet. also carb cleaner likely damaged the floating valve seal on the slide. replace this seal. verify the seal and the floating valve plate are installed in the correct orientation. install the JD Jetting kit if you don't already have it. it will get your jetting spot on and eliminate this as a potential issue. check your accelerator pump (AP) diaphragm. these are known to deteriorate over time. replace it witht he AP update kit we offer. check our how-to for proper installation of this kit. once installed or verified good check for strong and long AP squirt.

as mentioned, verify your timing and your valve clearance. check the auto-decomp for proper function. check for strong and consistent spark.

if the bike is still hard to start i would be concerned about valve head damage caused by the piston by piston contact you mentioned. if they were bent even slightly then it would reduce seal and limit compression.

report back.

ken

[imlandwert]

ok thank you guys alot!! so ill order a jet kit and the new floating valve seal, i checked the spark when i put it back together and it had spark, the auto decompressor was working right, and what about the idle problem im having?? should the new jets fix that problem as well?

[MattBennett23]

Pilot jet effects idle and the very beginning of throttle usage. This and the fuel screw could effect the idle. I would replace the pilot jet and adjust your fuel screw and see if it makes a difference.

[crfsonly]

if the floating valve seal is damaged or the seal or plate are installed incorrectly this will cause a poor or erratic idle. the same is true if the pilot jet and fuel screw are not functioning correctly. check your fuel screw and make sure all three of the o-ring, washer and spring are installed correctly.

[imlandwert]

ok i ordered a carb rebuild kit to install, hopefully itll get here soon!! haha cant wait to get rippin again! and how many turns out for idle screw and how many turns for fuel mixture screw? or do i have to play with those?

[MattBennett23]

Depends on your setup, there are the settings others are using if you search this site for jetting stickies. On my 250x i have the fuel screw 1 3/4 turns out, dont know about a 250r. Start around there I would guess and adjust it as needed.

[MattBennett23]

http://www.crfsonly.com/forum/viewtopic.php?t=13470&highlight=jetting

[imlandwert]

Ok guys sorry its taken me so long to reply, I just got my parts in yesterday finally, I rebuilt the carb, I checked my valve clearences and they are good, I put it all back together but it won't start, I think I have the cam 180 out, how do I tell?? I know you line up the marks on the left and right side and on the cam but which way are the lobes suppost to be facing?

[crfsonly]

follow this how-to:

http://crfsonly.com/howto/crf250x/crf-v ... stment.php

basically you set the timing marks with the lobes of the cam facing to the rear of the bike.

[imlandwert]

Ok guys sorry its been forever that I've gotten back to you, but I've gotten my bike runnin!! YAYY...BUT there is still oneee problem haha, when you are riding and turn the throttle quick it bogs a little then jumps?? An idea of wat it would be? I was thinkin I need a bigger main jet as I have a pro circut T4 on my bike, I've added the 08 upgraded AP new floating valve seal, rebuilt carb, other than the bog she runs great and I love it!

[crfsonly]

main jet does not influence off-idle performance. what jetting do you have in the carb currently? if you don't have the jd jetting kit we offer then get it. also, get one of the fuel screws we offer as this will allow you to adjust the pilot circuit which affects off-idle performance.

ken