1981 Yamaha XJ650 Maxim Valve clearance/ carb issues

Alright so new problem, and I figured I'd better address this before I try adjusting the mixture. first of all, it won't Idle at all unless i set the idle screw above 2k rpm if it drops below 1.5k even if I blip the throttle there is a very good possibility that it will die, it bogs down a little then will sputter and die. I took it on a 3 minute drive which I noticed when I got to third gear if I tried to increase the throttle (traveling at about 30mph) it would bog down and sputter like it was going to die, and I would have to downshift to second gear where the revs would jump to about 4k and I could then open the throttle, and the bike would accelerate wonderfully, then I could move into third gear without too much trouble (at about 35-40mph) for cruising. as I started going up a hill in third gear it bogged down again and so I down shifted to second and it bogged down again, then I shifted to first where it sputtered and died.. I tried to immediately start it (with the choke on) and got nothing, so I let it sit. about 3 or 4 minutes later I tried starting it, and i got a bit of a sputter, then a thrumping sound like it was trying to start, but it didn't want to just yet. let it sit for another 2-3 minutes, then cranked it over again, and with a little hesitation it finally started, giving it some revs I managed to make it home without too much trouble, at high rpms I have absolutely no problems what so ever, besides maybe a little backfire when I let off the gas. at low RPMs it struggles.. hopefully I gave you guys enough information on the symptoms I'm having. I think it's possible that I didn't get the carbs synced perfectly when I did them, so that's a possibility.. but I'm not sure if these symptoms show out of sync carbs, or plugged jets (again...) I've got an inline fuel filter on it now, so there really shouldn't be any foreign particles in the carbs, not saying it isn't impossible though.. anyways, thanks for reading all of this, and hopefully someone has had similar problems and managed to fix it! Thanks a bunch you guys!!

 

And you've accurately and individually WET-set the float levels to spec?

 

yup, I checked the wet float and everything... they were all pretty low, about where one on the bolts for the float bowl seated. I put them between 1 and 3mm from the top of the bowl.. I could try checking them again if you think that's what it is.

 

dID YOU CHECK YOUR PLUGS? ARE THEY BLACK LIKE TOO RICH OR WHITE LIKE TOO LEAN? whEN THE BIKE BUGS LIKE THAT, (sorry) it is not easy to tell if it is a rich bug or a lean bug. It alos could be ignition related

 

I haven't really tried to check them yet. I wasn't going to really bother with it until I could figure out the problem I'm having right now.. the bike should idle even if I have all the screws set at 3 turns out. I guess the thing I could do is run it for a little and when I have that problem again kill it, and remove the plugs to see see what it's showing

 

http://www.aa1car.com/library/reading_spark_plugs.jpg

 

Wet-setting floats: http://www.xj4ever.com/setting%20fuel%20levels.pdf

Your bike has a spec for its float levels. Put them in spec.

Did you replace the o-rings on the pilot mixture screws?

 

No I didn't replace those o-rings, I have no idea where you can get them haha. I did wet set them though, I believe the spec is 1-3mm and they are pretty dang close last time I adjusted them. I think I figured it out though... this is super embarrassing.. but.. I ran it out of gas... yup. go ahead and laugh all you want, when I realized that I *face palmed* pretty dang hard haha. I didn't even think that it was a viable possibility though because I had put about two gallons in it, and according the the tach, I've put maybe 40 miles on it. but now that I think about it I did let it idle a lot when i was doing the tests and everything, plus a decent amount spilled out when I was trying to sync the carbs, so it makes sense hahaha. So I put some gas in it and primed it, took a few tries, but it started with the choke on just fine. I was worried that I had picked up some debris from the bottom of the tank, but the inline fuel filter took care of that, and I didn't notice any major particles in it. I haven't really had a chance to ride it around and try to make some more adjustments, but I'll probably still have a problem with it idling, low gas shouldn't wouldn't cause idling problems would it?

 

and I'm pretty sure the reason why it was acting like it was out of gas and stalling on me.. was because it was.. hahaha so hopefully I don't have that problem again..