louis
XS650 Addict
Thanks 5twins, any tips on how to twist the brass floats back if they are indeed uneven?
Also, any reason this issue would surface suddenly?
Also, any reason this issue would surface suddenly?
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Running Rich/Flooding/Choke Issues
- Thread starter louis
- Start date
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- Tags
- carburetors
Basically, you just remove the float, hold one "bulb" in each hand, and gently twist them in opposite directions. Which way you twist depends on which way they need to go to be made level. I don't know why it would occur suddenly. Another possibility is if your replacement float needles and seats are aftermarket, they could be junk. My dealer won't even use the aftermarket ones anymore, he's had so many problems with them.
louis
XS650 Addict
Needles and seats are aftermarket (Mikes), but i visually inspected them shutting off fuel when I raised the float with my fingers, is this not sufficient to say they are sound?
I'm pretty close to replacing these carbs.
I'm pretty close to replacing these carbs.
Some members had issues with float valve lengths and aftermarket float tangs that made the tang/valve angle somewhat different from 90°. It's best when the tang isn't pushing the float valve needle to the side.
Something else to check would be the main jet air bleed. It's small, and if something constricts or plugs it the main fuel system will run crappy (rich, throttle lag)...
louis
XS650 Addict
Okay, I'll make sure the floats are even using a steel ruler and will blast the main jets with some air to make sure they are clear.
If this doesn't improve the way the bike is running then I'm looking to replace these carbs. I won't be replacing it with the stock BS38's. I'm sure you two have replaced carbs 21248294 times so what's the best option in your experience?
If this doesn't improve the way the bike is running then I'm looking to replace these carbs. I won't be replacing it with the stock BS38's. I'm sure you two have replaced carbs 21248294 times so what's the best option in your experience?
AIR jets. The ones that appear around the periphery of the carb's intake bell.
These air (bleed) jets supply air to the tiny holes in the needle jet (what some of us used to call aerators, or "percolator towers"). Here's a pic of my '71 air jets. Yours will be somewhat different.
I think you should dissasemble and inspect your choke. Dirt under the plunger or varnish on the plunger bore might be preventing the plunger from allowing the choke to completely close.
Later BS38s have a rubber choke gasket and the plunger tip is rubber -- not sure about your year, but because of the possibility that there are rubber parts in your choke I would not spray it with carb cleaner which ruins rubber.
louis
XS650 Addict
Brass float was twisted, left hand side was 25mm and right hand side was closer 30mm. The reason the bike was so slow is because the the rich condition was fouling the right plug and it was firing 1/10 times so I was basically running on one cylinder without realising.
Took it for a 50 kilometre ride today and it didn't miss a beat. Thanks for all your help. I still find that these bikes run quite rich no matter what I do and I have ten or so friends with XS's and they all foul plugs. Maybe it's the hot Australian weather.
Took it for a 50 kilometre ride today and it didn't miss a beat. Thanks for all your help. I still find that these bikes run quite rich no matter what I do and I have ten or so friends with XS's and they all foul plugs. Maybe it's the hot Australian weather.
CDNTX650
XS650 Guru
They don't run rich. If they are fouling plugs, It's not set up properly then. And running that rich is a surefire way to a fast top end overhaul from all the carbon and cylinder wash.
You mentioned you replaced all the jets. With what? Hint; many kits have wrong jets included. Any non mikuni jets are suspect.
Early two throttle cable carbs are futzy. it takes very little to upset carb synch.
I have a 73 with stock carbs that I redid a couple of years ago. pulled it out of the shed this spring, it started with the electric start first try and I rode it semi regularly this year, never fouled a plug. It starts with choke when cold. No choke needed when warm. Like all BS38s it's a bit of a pain to keep it running during the warm up. Can't just start it and go find your gloves....
I'll just touch on floats again, the dip test is HOT water, hold with a pliers and submerge for just a second or two. I find most old floats have radial cracks all around the edge. Any bike I plan on riding gets new genuine floats. AFAIK 650 central has the best price on the real ones.
Early two throttle cable carbs are futzy. it takes very little to upset carb synch.
I have a 73 with stock carbs that I redid a couple of years ago. pulled it out of the shed this spring, it started with the electric start first try and I rode it semi regularly this year, never fouled a plug. It starts with choke when cold. No choke needed when warm. Like all BS38s it's a bit of a pain to keep it running during the warm up. Can't just start it and go find your gloves....
I'll just touch on floats again, the dip test is HOT water, hold with a pliers and submerge for just a second or two. I find most old floats have radial cracks all around the edge. Any bike I plan on riding gets new genuine floats. AFAIK 650 central has the best price on the real ones.
