Kgreenhaw
XS650 Enthusiast
I recently rebuilt my engine and was having issues with one of the cylinders running rich at idle. I went through everything and finally found what the problem was. The float bowl. I swapped carbs from left to right and the rich condition followed the carb. I then swapped float bowls and the issue followed the bowl. to double check it wasn't the pilot jets i swapped those too and there was no change. Both carbs have #45 pilot jets.
My first thought was maybe the pilot jet wasn't seating all the way and was letting too much fuel through. I removed the pilot jet and saw that the seat in the bowl looked a little corroded/pitted. I found a drill bit that had the same angle as the pilot jet and gently "reamed" the seat to possibly help the pilot seal. Put everything back together and it made no change. I can turn the mix screw all the way in and it does nothing. I also tried a smaller pilot (42.5) and it ran way too lean even bringing the mix screw out multiple turns.
I thought about trying another bowl but when I search images I can't find one that looks the same as what I have. I'm stumped. there are no letter stampings and the hole along the front edge that lines up with a pickup tube is on the opposite side of the bowl...
I rebuilt the carbs before the engine, and got them dialed it. they sat for a few months while I rebuilt the engine and reassembled the bike. The carbs were soda blasted and cleaned. All passages were blown out with compressed air and brake clean. Since the issue started I disassembled and cleaned multiple times. I'm pretty much lost at this point...
My first thought was maybe the pilot jet wasn't seating all the way and was letting too much fuel through. I removed the pilot jet and saw that the seat in the bowl looked a little corroded/pitted. I found a drill bit that had the same angle as the pilot jet and gently "reamed" the seat to possibly help the pilot seal. Put everything back together and it made no change. I can turn the mix screw all the way in and it does nothing. I also tried a smaller pilot (42.5) and it ran way too lean even bringing the mix screw out multiple turns.
I thought about trying another bowl but when I search images I can't find one that looks the same as what I have. I'm stumped. there are no letter stampings and the hole along the front edge that lines up with a pickup tube is on the opposite side of the bowl...
I rebuilt the carbs before the engine, and got them dialed it. they sat for a few months while I rebuilt the engine and reassembled the bike. The carbs were soda blasted and cleaned. All passages were blown out with compressed air and brake clean. Since the issue started I disassembled and cleaned multiple times. I'm pretty much lost at this point...