I have a 2003 Scrambler 500 HO I just picked up. It runs but doesnt idle correctly also doesnt run smooth at any RPM. I have had Carb apart and cleaned. Checked Timing marks. Adjusted Valves. Checked the Camshaft. I'm kinda at a loss. Not sure what else to do. I feel its Carb related but not 100% Any Help would really be appreciated!

 

Are you sure the carb is 100% clean? Did you buy a carb kit? Idle screw mixture screw set correctly? The one jet has a very tiny orifice. Fuel filter replaced? How does the diaphragm look on the top side of the carb?

 

wfburton159 Thanks for getting back to me
Yes I had the carb apart a couple of times double checking myself and everything seems good. I took another engine I have from another 500 I bought for parts and installed it with same carb.It didn't run at first so i checked the pulse coil and saw it was too tight also reset the valve lash and It fired up and runs like new with the carb I had redone. So I have to put the other engine back in and try and figure it out! I will start with pulse coil also and try valve lash and see what happens,Kinda the hard way to eliminate the carb but i'm glad I didn't go for another one.

 

Holy cow that is a lot of work! Glad you know you have one good running engine.

 

Yes It wasn't too bad swapping them over cause I have all the plastics off anyway. But I just needed to eliminate some of the things I thought it may be such as carb,fuel pump, electrical and so on. But I really want to get the engine that was in this bike running right so I'll keep you posted on my findings. Again Thanks for getting back to me!

 

have you checked adjusted ETC cable?

 

la90043
Yes made sure there was no contact. even installed a cut zip tie (temporarily) to be sure. Didn't help.

 

Give it more fuel with pilot screw and see what happens? Then lean it out with pilot screw and see what happens too.

 

oh yeah remember your initial setting beforehand.

 

I already messed around with the A/F mixture screw Oddly enough it was set at about 3/4 out when I started but seems to run ok at about 1 1/2 out. I'm interested to see if I have to change the setting with the other engine. I wouldn't think so.