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Guest
Guest
I've been learning a LOT about the finer details of the carbs on my 850. Last week I resolved the high idle issue by installing a new un-bent throttle butterfly on the #3 carb (apparently these bikes don't like potato chip-shaped butterfly valves). Then the #3 cylinder wouldn't fire for the first 3 or 4 minutes after I started the bike. After studying an animated graphic on Youtube, I realized that at low RPMs, the engine is running solely on the pilot circuit, so I checked everything in that circuit and low and behold, discovered the choke pickup tube was clogged. Several good blasts from both ends with carb cleaner got it cleaned out nicely (I cleaned the other three while I had the carbs off as well - just in case). After my first improperly performed bench sync yielded horrible results, I redid it, then used another member's Carbtune Pro to balance them, and have finally gotten the bike to idle reliably at 1100 RPM. So right now, the bike still sputters and backfires a bit, so I'll install new plugs next and see if that fixes the problem.
Also, after comparing the brass adapter tubes for the Carbtune (which have rubber o-rings) to the hex screws in the vacuum ports on the intake boots (which did NOT have o-rings), I realized that may have been a source of a vacuum leak. After consulting the parts fiche online, I learned that there is indeed supposed to be a gasket on those screws, so I added them.
For those who may be interested in the Youtube video mentioned above, here is the link:
https://www.youtube.com/watch?v=wyspAHrMbb8
Also, after comparing the brass adapter tubes for the Carbtune (which have rubber o-rings) to the hex screws in the vacuum ports on the intake boots (which did NOT have o-rings), I realized that may have been a source of a vacuum leak. After consulting the parts fiche online, I learned that there is indeed supposed to be a gasket on those screws, so I added them.
For those who may be interested in the Youtube video mentioned above, here is the link:
https://www.youtube.com/watch?v=wyspAHrMbb8
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