Hi all- This site is the best- Here's my problem- I have a 1975 XS650b with stock airbox, and stock jetting- The pipes are more straight through with minor baffling. For my bike to run well (and it does run well) I have to turn my mixture screws way in (about 1/4 turn out on the left carb and only an 1/8 out on the right carb!) I also have to adjust the idle screw way more in on the right side than the left. With more open pipes I thought I'd be looking at a leaner mixture to begin with. With the carbs dialed in this way the bike runs great and the plugs look great. I've had the carbs off about 15 times, could I have messed something up? Why would it run so rich? Gas milage also seems less than optimal- Any suggestion would be greatly appreciated- Also valve clearances are spot on and timing is right in range. ??? Thanks again.
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Carbs Too Rich?
- Thread starter johnnymac
- Start date
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- Tags
- carburetor
How many miles? I've read that needles can wear quite a bit and richen things up. 
It only has 7000 miles on it- and the carbs look spotless after cleaning them multiple times- I just bought a spare used pair of carbs on ebay for $45.00 
. I'll clean them up and slap them on and see what happens- I'm still puzzled.
. I'll clean them up and slap them on and see what happens- I'm still puzzled.Update- I got these carbs on ebay for $40.0- One slide was frozen and they were both missing some screws. The carbs that I had on my bike were stock with only 7000 miles on them and they looked spotless inside (after cleaning 6 times) but ran like crap- These ebay ones on the other hand looked like total crap, but I stripped them down and dipped all non-rubber parts and sprayed the holy crap out of them with carb cleaner- The PO of these ebay carbs stripped screws and took 100 grit sand paper and sanded the butterfly on one side? I put them back together not expecting my old xs to even start. Not only did she start up- She purred at 1200- Almost all vibrations were gone- The excelleration was fantastic and the plugs- PERFECT I guess the moral of this story is to not judge a carb by its outward appearance!!! I am almost still in disbelief- I want to thank this forum and all on it for all of the great info- The carb manual was fantastic- Thanks Again-
I guess the moral of this story is to not judge a carb by its outward appearance!!! I am almost still in disbelief- I want to thank this forum and all on it for all of the great info- The carb manual was fantastic- Thanks Again-Attachments
bloodthirstysystem
XS650 Addict
with the stock air box i doubt straight pipes would have much of an effect on the jetting, especially with baffles.
i'm not sure how many turns the '75 mixture screw is supposed to be but i'd say if the plugs look good then keep riding
i'm not sure how many turns the '75 mixture screw is supposed to be but i'd say if the plugs look good then keep riding
I'm glad you got it running right. Are you going to keep messing the original carbs and get them figured out? Float height maybe?
Yes- I plan on working with them until I get them right also- The float heights are right on- but the carbs sat on the bike outdoors uncovered for about 18 years and I'm afraid there might some internal corrosion in passages I can't see. Now I know how well the bike should run, I'll work on them- I can really tear into them now that they are the extra set- Nothing to lose! Thanks again for all the advice-
Just an extra note- Now that the bike runs so well- The shifting problems from neutral to first and first to neutral seems cured- I was just going to rip into the clutch- But for now it seems I won't have to. The bike shifts beautifully now-It just seems to keep getting better-
