You said you found someone parting out a 650? For carbs, you want a '76 or later set, one where the carbs are linked together as a "bank" and only use one throttle cable.
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New bike, The works
- Thread starter Calev
- Start date
Calev
XS650 Member
Had sometime last night to check my valve clearances for intake and exhaust. Exhaust was perfect at .006", but intake was loose, loose enough to jiggle a .003" feeler. Readjusted the intake for both sides at TDC accordingly. I also checked the points for wear and set the gaps. I did not play with the ignition timing as I did not have a 12v light to add with a proper adjustment. I used this video as a guide. All of these adjustments were done with a cold engine.
Went for a short test drive and it was a nice improvement. The left side has about the same pressure coming out of the exhaust and sounds much better. The bike runs significantly better. Before it had a hard time when riding from a stop or slowly riding at 2500rpms in 1st/2nd gear. If I blipped the throttle it would hesitate for a split second and then ramp up, now there is now hesitation. Riding at 3000+ rpm feels and sounds smoother.
My guess is the combination of intake valve & points adjustment has done it. I still want to check the timing and make sure that it's in proper order next.
Went for a short test drive and it was a nice improvement. The left side has about the same pressure coming out of the exhaust and sounds much better. The bike runs significantly better. Before it had a hard time when riding from a stop or slowly riding at 2500rpms in 1st/2nd gear. If I blipped the throttle it would hesitate for a split second and then ramp up, now there is now hesitation. Riding at 3000+ rpm feels and sounds smoother.
My guess is the combination of intake valve & points adjustment has done it. I still want to check the timing and make sure that it's in proper order next.
Calev
XS650 Member
They are parting out a 1980 XS650 special. I believe the carb bank they are selling are BS34s.
Yes, if the carbs are the originals, they would be BS34s. They're a good carb set, once you jet past the factory lean settings (one up on the mains, 2 down on the air jets for an all stock machine, 2 up on the mains, one up on the pilots, and one down on the air jet for your typical "pipes and pods" mod).
Not sure about what setup what carburetors ..but for thinking out loud I get the impression ignition is to late
I rattles a bit at start and the throttle response is not stellar
in the video . I would check ignition with a strobe lamp . Before carburetor work. Depends on choke and if it is a cold start
But ignition check must be done and firing evenly on both cylinders
I rattles a bit at start and the throttle response is not stellar
in the video . I would check ignition with a strobe lamp . Before carburetor work. Depends on choke and if it is a cold start
But ignition check must be done and firing evenly on both cylinders
Calev
XS650 Member
Update, I checked the timing and found that it has been firing fairly late. I tried to advance the points as far as I could following advice from this forum and videos but it not quite enough. I played around with adjusting the gap on the points to help with timing and that sort of did the trick. Not sure if I need a new chain, points assembly, or tensioner. Something is worn out causing this to fire late.
I picked up a bank of BS34’s last night with air box and new filters. not sure if I can use the air box as it’s for the XS650G Special II. The person who sold me the carbs didn’t have the boots as they were cracked when they took them off his bike. are these boots assembly something I should order off eBay or MikesXS?
Also when I bought the carbs the seller let me take the gauge cluster with speedo and tach. My speedos magnets and worm gears gave up so that was convenient.
I picked up a bank of BS34’s last night with air box and new filters. not sure if I can use the air box as it’s for the XS650G Special II. The person who sold me the carbs didn’t have the boots as they were cracked when they took them off his bike. are these boots assembly something I should order off eBay or MikesXS?
Also when I bought the carbs the seller let me take the gauge cluster with speedo and tach. My speedos magnets and worm gears gave up so that was convenient.
I don’t know where the Mike’s carb boots are made but I believe these are made in Japan.
http://www.nichecycle.com/ncs/categ...-carburetor-flange-set-left-right-by-ncs.html
http://www.nichecycle.com/ncs/categ...-carburetor-flange-set-left-right-by-ncs.html
I don't think those will fit the BS34's, they say they have an I.D. of 45mm. That would be closer to the BS38 size .....
Calev
XS650 Member
Howdy y'all. Some time has passed, and I am on the tail end on putting my bike back together.
I finished a top end rebuild and now I am working on installing a PMA system. This install was not originally planned but I changed my mind. I had originally bought a windy nation rectifier and a VR-170 regulator back when I first started this post.
Since I am changing to a PMA system, I want to know if I can repurpose the rectifier and regulator instead of buying a combo reg/rec? I search around the forum for a wiring diagram for a PMA with separate reg/rec system but haven't found an answer. Anyone have any insight?
I finished a top end rebuild and now I am working on installing a PMA system. This install was not originally planned but I changed my mind. I had originally bought a windy nation rectifier and a VR-170 regulator back when I first started this post.
Since I am changing to a PMA system, I want to know if I can repurpose the rectifier and regulator instead of buying a combo reg/rec? I search around the forum for a wiring diagram for a PMA with separate reg/rec system but haven't found an answer. Anyone have any insight?
Nope. Two different regulators. Neither works for the other.
