A carb sync with a homemade manometer cleared things up this afternoon. Thanks, Chris Payne
On Thu, Apr 22, 2010 at 10:13 PM, Chris Payne <[email protected]> wrote: > Hi folks - > > I posted this over on Nighthawk-Forums.com, but thought I'd try to > elicit opinions from this list as well. > > My bike ('84 Nighthawk 650) has an issue. It hesitates or bogs around > 1/4 to 1/2 throttle when under load. It starts and idles wonderfully; > can twist the throttle when in neutral, etc with no hesitation as > well. It also seems to be independent of engine speed. It happens when > taking off from a stop and also when you twist the throttle at speed. > Once it gets past this hesitation, it takes off like mad. It does not > backfire, sputter, etc. > > Last year, the bike was hard to start, idled poorly, and needed a long > time to warm up along with exhibiting the above behavior. I attributed > all of this to dirty carbs (the bike had sat for a long time, the > odometer read just over 4k miles when I rescued it from a barn last > May). I shipped the carbs off to a guy to have them professionally > looked over. He cleaned, inspected, and visually synced them. The bike > is 95% better now, but still has the hesitation that I'm trying to > diagnose. > > My tests so far - > * carb cleaner on intake boots, and around/over/on carbs in general, > searching for leak. No rpm changes. > * remove air filter. No change. > * tape off half of air filter. No change. > * turned out mixture screws half turn. No change. > * washer mod. No change. > * Coil voltage - fine at > 11.5 volts > * choke cable allows full movement > * it has a new fuel line and fuel filter (run of the mill Briggs) > * new plugs > * plug wire resistance OK on all 4 > > Next in my list is a carb sync. > > Any comments or recommendations? > > Thanks, > Chris > -- 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]. For more options, visit this group at http://groups.google.com/group/nighthawk_lovers?hl=en.
