Thread bump:
Quote:
Originally Posted by redsnapper
MISCELLANEOUS INFORMATION ABOUT YOUR BIKE’S JETTING SETUP:
Pulls hard to redline, middle range is great, no choke needed at all to start, but hard to control low end. If I just crack the throttle it pulls too hard, Sparks plugs are black, If I apply choke the bike stalls, I smell gas from the exhaust, Fuel mileage is bad news. Bike is running too rich. Tried adjusting mixture screws, Valves adjustment, carb sync, cleaned carbs. Will trying adjusting needles to 2 clip position from top to make it less rich to see if it fixes my low end,not make my spark plugs black, and fix fuel mileage.
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If it pulls hard to redline, it's not the main. If the midrange is good, it's not the needles, but those are in charge with the throttle ranges you typically use for daily use so they are a large influence to your mileage. Personally I don't tune for mileage at all. Still worth a shot at lowering your needle a tad to see if you can lean the mid throttle a tad without hurting rideablity but idk how successful that's going to be. Try using SAE #4 washers to get "half steps" on your needle clip positions and dial it as lean as you can go without taking away mid range smoothness.
As for the mix screws, I'm betting this is part of why you're getting black plugs. Plug checks are really only valid if you're able to cut the engine immediately after operating at the throttle position and rpm range in question. Ergo, if you want to test the mains, you need to hit the kill switch at wot and 11,000+ and immediately pull the plug. As you can see this is not convenient for those of us without dyno access. Anyhow, with no snorkel and a drop in filter, start the mix screws at 2.5 turns and adjust as necessary to get a responsive throttle. Do not change the mix screws significantly to help start up. This is what the choke is for. Needing choke or not needing choke at start up is not a good measure of your bikes health. Choke at start up for a short period is normal and totally fine. To have a smooth start up that helps the engine start easily and warm up quickly, every vehicle I know of has some way to richen the mixture and/or raise the idle while cold. So it's totally fine to use a little choke to start, adjust it back so the bike idles at 2000-2500 rpm or so until the throttle response is normal, then ride off and turn the choke down as you go. If your choke kills the bike instead of raising the idle, I'd bet your mix screws are set too rich. Start at 2.5 turns and go in 1/8 turn increments as needed. If you need less than 2 turns or more than 3, change idle jet sizes to suit.
Remember that idle mixture is in charge for small throttle openings, needles are in charge of the mid range, and the main jet is in charge for large throttle openings. If you can isolate when the bike feels funny, you can figure out which part needs adjusted and do it once and save yourself the hassle of working on the wrong part.