YAMAHA CHOPPER PROJECT
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2004/03/31:
So my car is in the shop and I want to get a feel for the bike and how she runs. Runs fine for one day, then the next morning on the way to work, it feels like it's running at half power and it sounds off. I pull over and find that fuel is pouring onto the street from around the carbs.
The XS 750 uses vacuum petcocks, which means there's no "off" position, only "on", "reserve", and "prime". Obviously the automatic "off" is not working. We found out later from another XS owner that those petcocks can get stuck, especially on old gummed up bikes that haven't been run in 18 years. Although the problem may actually be due to the carbs getting gummed up or the floats stuck, letting the fuel continue to flow (and overflow).
In retrospect I should have fetched a jerry-can and drained the fuel into it, but being without transportation and late for work, I left the bike to its own devices.
Sean was kind enough to swing by and pick the bike up. We poured a bit of fuel in to get a look at the problem, and sure enough, it started draining out through the air filter. Time to bring the bike to meet The Barn.
After taking the carbs apart and putting them back together, the bike ran again. We didn't really do anything, but it worked.
Then Sean rode the bike home. The bike died on the way. After a kick start it died soon again. And again, more and more frequently, until it had to be pushed the last couple blocks.
Sean took the carbs apart more fully, blew out the passages, and she seemed to run well. Problem solved?

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email: mikebike@rocketcar.net