this isn't sled related, but since this is the best yamaha help site there is 
and there isn't as much traffic in the ATV section, I figured I'd post here.
I have a 2001 Yamaha Raptor 660. I went through the carbs but I forgot
to check how many turns the fuel screws were at before I removed them. I can't find what the settings are in the owner's or service manuals either. Anyway I got it all back together and I don't think I've got the screws quite right. It's harder to start than it was before unless you choke it a little. It doesn't idle very well either, but if you give it a little choke the rpm's go up noticeably and it idles well. So I'm thinking this indicates that I'm lean in the pilot circuit? Also, there is some slight popping when letting off the throttle at high rpms. I'm thinking that it could be related to the fuel screws since the carb uses all circuits in the upper throttle ranges. What do you guys think? Thanks
and there isn't as much traffic in the ATV section, I figured I'd post here.I have a 2001 Yamaha Raptor 660. I went through the carbs but I forgot
to check how many turns the fuel screws were at before I removed them. I can't find what the settings are in the owner's or service manuals either. Anyway I got it all back together and I don't think I've got the screws quite right. It's harder to start than it was before unless you choke it a little. It doesn't idle very well either, but if you give it a little choke the rpm's go up noticeably and it idles well. So I'm thinking this indicates that I'm lean in the pilot circuit? Also, there is some slight popping when letting off the throttle at high rpms. I'm thinking that it could be related to the fuel screws since the carb uses all circuits in the upper throttle ranges. What do you guys think? Thanksrx1jim
New member
On most of the ATV and sled carbs that I have worked on, the setting for these screws is usually somewhere between 1.25 turns out (my SRX) and 2.25 turns out (my RX-1). I would start at 1.5 turns out and start from there. It does sound like your current setting is causing a lean condition. If you change the screw setting and there is no performance change, then the low speed circuit is clogged. I use a lot of carb cleaner and compressed air to make sure the carb circuits are clean.