Help with idle mix and top speed:So last night around midnight I moved the needle to the richest notch. I'm running CV carb with 17.5 pilot, 120 main, big exposed K&N filter, and bazooka with the hot pipe removed. Just got back from my test rides and this is what I've found:When setup by the dealer, idle screw setting was way out... didn't measure it, but it was somewhere in the order of 6-8 turns out. That always ran great with my stock setup.2-2.5 turns out is my highest idle speed. I brought it to 3 to be on the rich side. When I rode it down an exit or two on the highway though, it could barely maintain 55 comfortably (using 1/4 to 1/2 throttle). 1/8 throttle was super quick to respond, but lacked the gusto once it got to 1/4 throttle. No real power per-say.Stopped at a gas station, and brought the idle screw to 5 turns out. Did the same highway test, and this maintained a higher comfortable cruising speed... almost 60 mph at half throttle. Still not super comfortable there, so I did it again.At 7 turns out, it can maintain idle once warm (no throttle needed to keep it from dying at stop lights), has a delayed attack when blipping the throttle, but has some serious gusto once it hits. Also, I can easily maintain 60 mph or slightly more at about half throttle. Anything higher than that and I get these 'over-revving' sounds that I (maybe falsely) attribute to dryness, leanness, and/or overheating.It still feels fairly dead when cranking any higher than half throttle at highway RPM's, but what could this mean? Shim it richer than the richest notch on my needle? Go to a larger main jet? Also, is it bad that I have my mixture screw set so much richer than its 'sweet spot' as far as idle is concerned? I don't mind the 'calm before the storm' delayed response when blipping the throttle if it means I have more power at the useable range. Plug is a chalky brown... a little lighter than hershey's chocolate, not white.I'm tempted to try my 122.5 main. I also have a 125. From what I've read, the AVL is known for this low end power that I'm getting, and that is great. Should I try and get more out of the top end, or will everything else suffer?Comments, questions, pointers, and the like... let me hear it all. I know nothing about this besides what I've read here and last night I finally popped my 'getting inside a carburetor' cherry.
Comments, questions, pointers, and the like... let me hear it all. I know nothing about this besides what I've read here and last night I finally popped my 'getting inside a carburetor' cherry.
We'll try some plug chops and probably a bigger main jet, then go from there. That being said, how pray tell does one 'shim' up the needle? Do you just put a little washer-like thing beneath the white plastic needle collar? Like between the needle's collar and the bottom of the slide assembly? If so, what happens with the little plastic nub that protrudes down from the collar and feeds through a tiny hole in the slide... seems like it'd get in the way, or the needle would lay crooked...?Thanks again for any input. Keep it comin cause I really have no idea what I'm doing. It's fun though, isn't it?
well, I am not a real expert. The fuel enriching knob is hard to reach without leaning over and hunting for it. I have learned to live with a fast idle so the bike will run normally at all other speeds. Set where it is only takes me two kicks at most and usually only one to start it. It puts real slow when cold and a little too fast when warm, but I can live with it. I get between 65 and 70 mpg and running it a little rich at idle doesn't seem to bother the AVL at all. my 2 cents.
Sounds to me like you are talking about the idle speed screw not the enrichener. Increasing the idle with the idle speed screw doesn't change the idle fuel/air mixture. Running at a fast idle doesn't effect how the bike runs at RPMS above idle. It just burns more gas at stop signs (among other things, clutch wear, etc.).
I just recently found the enricher screw through a thread here. I hunted around for it and decided that there was only one screw. Still, I have had no problems with the CV carb. I still have been getting 65-70 mpg set like it is. I'll mess with it some if needed, but so far it doesn't bother me.
I think both of those posts deserve an, 'Amen.' So, Amen, Gentlemen! After checking the plug from last ride, it's charred and black. Cakey even. Definitely running rich, but I imagine that was due to my massively enrichened mixture screw.Today after work I put the 122.5 main jet in and a fresh sparky and took it for a spin. Shot up I-95 for a few exits, and did a plug chop on the side of the interstate at full throttle. I was amazed at how the enfield pulled, even at half throttle. I was able to maintain 65 mph no problem, and I was able to get up ABOVE 70 mph. It felt like it could've hit 80 but I didn't want to break something (or myself).At the full throttle plug chop, the brand new spark plug I put in was chalky and white. Shockingly, I'm still running lean at full throttle. I got gas at an exit, then shot back down the interstate for about 5 miles at half throttle. This maintained about 60-62 mph no problem. I did another plug chop at half throttle (but with the same plug that I just used for full throttle). It was chalky and white again even at half throttle. I don't know enough about plug chops to tell how accurate this reading was. I read somewhere that you should always do plug chops with a fresh plug, but I figured I ran it for enough miles at that half throttle setting that it would've darkened up if my half-throttle setting was significantly richer than WOT. Someone please enlighten me to the significance of fresh sparkies in richness testing...Pulled back in to home and leaned up the idle screw 2 full turns (now currently at 3 turns out if I remember correctly). The idle wasn't seeming strong, even after wailing it at WOT on the highway. I then swapped out the 122.5 main jet for my 125, which is the largest I have. I'm hoping I'm not still lean at WOT with this jet, but only time will tell. I'll get on it again tomorrow and try it on for size. My long awaited EMGO Reverse Cone Shorty Silencer has finally shipped too, so I'll soon be swapping the bazooka for it. I imagine that will lean things out a little bit more, eventhough I've already removed the hot-pipe.If this jet doesn't richen up my mid-throttle I think the next step is to shim up the needle a bit. I'll have to use some washers since the one cycle shop I called doesn't have mikuni shims. They said they have some could possible may work, but told me to bring in the carb to make sure. Sounds too much like hard work, so I'm gonna stick to the hardware store a block from my house. But first, the 125 main jet.Chuck
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