A little trivia: "Choke" on modern bikes is actually a misnomer. The function is now controlled by a "fuel enrichener" circuit built into the body of each carb.
The old skool method was a cable connected to the butterfly flap in the throat of a carb. It functioned by reducing (or choking off) air in the air/fuel mix momentarily, thereby increasing the amount of raw fuel being delivered during a cold start. Dunno the engineering reason for the changeover, but I would guess that it had something to do with simplifying the mechanical connection between carbs in a multi-carb setup. We still call it a choke cuz it's easier to say and the function is essentially the same. On Dec 10, 5:50 pm, Hawaii Sean <[email protected]> wrote: > Wow - great detail and I'm going to play with my choke just to see how it > works. > > Like everyone else I recommend changing the Oil and Oil Filter. Take a > good look at the Air Filter and at a minimum make sure it's clean and if > you can blow compressed air through it. If you don't have access to a > compressor the cans will work fine. You'll also find a plastic tube coming > out of the bottom of the air box, it will have a cap on the end sticking > down just below the frame on the right side further back than the clutch. > Pull the plug off and let it drain - caution nasty stuff will come out so > have something you can throw away under it. Let all this drip out and then > replace the plug. This tube is to drain liquid out of the air box. > cleaning it out once every 10,000 miles is a good idea. > > Your millage should be in the low 40's. I have a 12 mile commute in > traffic and get 42 to 44 miles to the gallon. Only 2 miles on the highway, > the rest are 35MPH surface streets. When on the "highway" for extended > periods (I live in Hawaii on Oahu, an extended period is about 30 miles) I > get 50mpg if not more. > > Best of luck and enjoy your bike. > > Sean > > > > On Monday, December 10, 2012 1:02:45 AM UTC-10, surfswab wrote: > > > First suggestion, buy a service manual. Clymer's a good one. > > > Second, fewer than 40 mpg in constant stop/go traffic is fairly > > normal, but almost half that is not. > > > Sounds like the engine is running rich. Are you mindful of turning > > choke off after warmup? If so, problem may be deeper. Try pulling > > the spark plugs and inspecting them. If they are sooty black or wet > > with gas that would confirm a rich mixture and might indicate a need > > for air/fuel mixture adjustment. > > > Also check the choke cable for proper adjustment. Follow the cable > > visually from the handlebars to the connection at the left side of the > > motor. A two-finger fork style fitting at the end of the cable > > operates brass pins built into the tops of the carbs. > > > With the engine off, move your choke lever from full on to full off > > and observe the operation of those pins (you'll probly be able to see > > only one of them. The rest are connected by a rod across all four > > carbs). If the choke is operating correctly, the brass pins should > > almost disappear into the carb bodies when you turn the choke off. > > With the choke full on, you should see about a quarter-inch of brass. > > Use your new service manual for adjustment procedures if needed. > > > I'd suggest new plugs in addition to a new air filter and oil change > > as already mentioned. Sniff the oil to make sure there's no gas smell > > coming from it. And empty blowby gases/water from the clear plastic > > tube hanging down from the frame, under your right foot peg (it has a > > plastic plug in the end) > > > Balancing the carbs wouldn't hurt either (service manual, again, for a > > description of the procedure). > > > The motor was designed to run on regular gas, so switching to higher > > octane would have no affect unless it's pinging or dieseling. > > > Before you put a wrench to it, though, try a weekend 100-150 mile, > > open road (non-stop/go) run to see if you're mileage figures improve. > > Should be in the low-mid 40s -- more, if you ride sedately, less if > > you don't. > > > On Dec 9, 6:07 pm, Sanna <[email protected]> wrote: > > > Hello > > > > Bought a 2000 NightHawk 750 3 months back. Been using to commute to > > work > > > about 15 Miles both ways, stop and go City traffic. Noticied I am > > getting > > > about 22-26 Miles a gallon. Switched to 93 Premium grade gas, almost > > same > > > thing. Please advise. I was hoping to get about 40 miles per gallon in > > the > > > City. I want to go for long rides / cross country during Summer. > > > > Your suggestions and advise is very much appreciated. Thank you. -- You received this message because you are subscribed to the Google Groups "Nighthawk Motorcycle Lovers!" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. Visit this group at http://groups.google.com/group/nighthawk_lovers?hl=en-US.
