Wrenchmorethanride
XS650 Enthusiast
So is the next step the dead cylinder adjustment to set idle higher? If so, any links for good instructions?
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Stupid question - brake light on cluster
- Thread starter Wrenchmorethanride
- Start date
Wrenchmorethanride
XS650 Enthusiast
Maybe I have more issues than just idle. I haven’t changed anything since last video. I shot this just now. Engine was warmed up. You can hear in the video at about 2 seconds it kinda surges sometimes at idle. Also, later in video I gave it some throttle and seems to miss or backfire. Seems worse than yesterday.
Idle as it is now is below 1000. Maybe 900 or so.
Battery is low maybe 11.98v. Does not seem to charge when running probably cause idle is too low?
Set your idle at 11/1200.
These aren't loping hardlys.
I'll add that charging seems to start around 1300. Don't be dismayed.
The 78/79 bs38's are good carbs and if you're running stock exhaust and stock carb air cleaners then the factory jets should be fine.
Points? I'm out on points....
These aren't loping hardlys.
I'll add that charging seems to start around 1300. Don't be dismayed.
The 78/79 bs38's are good carbs and if you're running stock exhaust and stock carb air cleaners then the factory jets should be fine.
Points? I'm out on points....
Last edited:
Wrenchmorethanride
XS650 Enthusiast
Can I just adjust the mixture screws or should I also use the dead cylinder adjustment?
A simple turning in on the idle/throttle adjustment screw located on the left carb will increase your idle....or decrease it if you turn it out.
The mixture screws on the carb sides have a suggested setting. Stick with that referred to in the manual.
Read the carb manual put together by grizzld1 and 5twins until "your eyes bleed" (I think is the common quote.)
Get those carbs to factory settings first. Get your idle to 11/1200 and see what you have.
Personally I bench set the dual carbs synchronization of the throttle plates using sewing needles, one in each throat, throttle plates holding them down and then adjusting for "grip". What's the thickness of a sewing needle? 1mm? 2 at best? That's not a lot of deviation once you get the same grip on both carbs. Remember- center adjustment screw is for the right carb only, left adjustment screw is for both.
Dead cylinder method? I'm not that anal. Other opinions may differ.
Excuse me now as I have to go outside and yell at some clouds.
The mixture screws on the carb sides have a suggested setting. Stick with that referred to in the manual.
Read the carb manual put together by grizzld1 and 5twins until "your eyes bleed" (I think is the common quote.)
Get those carbs to factory settings first. Get your idle to 11/1200 and see what you have.
Personally I bench set the dual carbs synchronization of the throttle plates using sewing needles, one in each throat, throttle plates holding them down and then adjusting for "grip". What's the thickness of a sewing needle? 1mm? 2 at best? That's not a lot of deviation once you get the same grip on both carbs. Remember- center adjustment screw is for the right carb only, left adjustment screw is for both.
Dead cylinder method? I'm not that anal. Other opinions may differ.
Excuse me now as I have to go outside and yell at some clouds.
Wrenchmorethanride
XS650 Enthusiast
Thanks. Downloaded the manual and will do some reading.
Wrenchmorethanride
XS650 Enthusiast
Another question. I have a couple of 4” Uni air filters I put on the bike. I assume they are not compatible with the original metal air filter housings? Or is there a trick to making them fit that I’m missing?
Thanks!
Thanks!
Are you asking about the airboxes or the side covers? You can re cover the OEM filters with foam if they are rotted.
I can confirm that. I've done mine, the foam was crumbling to dust. I got new foam the same colour as original. New air filters for a few £. And foam left over for next time.
Wrenchmorethanride
XS650 Enthusiast
Did you stitch the foam together?
No, I didn't actually. Used a combination of couple of narrow cable ties and glue. Over lapped the join slightly. Used K&N oil spray to give them a light oiling and left them to soak the oil up for a couple of days.
Wrenchmorethanride
XS650 Enthusiast
Thanks. I’ll give that a shot.
Just be careful when you are handling the filters removing and replacing the foam. The perforated sheet under the foam has edges like razor wire. If you aren't aware, you could shred your fingers, so be careful with it. Otherwise, it's an easy and well worth doing job.
The same foam used on high dollar filters is the same stuff they sell in sheets at the big-box store as AC window unit filters.
Wrenchmorethanride
XS650 Enthusiast
Hmmm. Mine didn't fall apart. Only the foam crumbled to dust.
First thought. Ultrasonic clean the bits. Thick beads of silicone mastic on the ends, press the bits together and leave a couple of days.
I’m thinking some epoxy would be gas and oil resistant. I don’t think I’ve ever seen one fall apart like that.
Wrenchmorethanride
XS650 Enthusiast
I used the method taught me by @Vincenthdfan. https://www.xs650.com/threads/reunited-with-xs650sh.63667/page-5#post-788014 Post #92
Wrenchmorethanride
XS650 Enthusiast
I think I have an electrical issue. Here’s what I’m dealing with.
I got a new battery. I also brought it to advance auto test. Tested ok
I also tested with another battery
When I turn on the key voltage drops about .8 volts at the battery. So if I start at 12.4 it drops to 11,5 or so.
Idle at 1200 and battery stays at around 11.6.
Rev to 2000 and voltage might get to 12v.
I checked resistance across main fuse and it is 0 (not started, key on)
I pulled other fuses and voltage does no go back up.
Turn key off and voltage goes back up
The idle is erratic and I wonder if it could be due to low voltage? Idles ok then will surge a bit then back down.
I’m looking at wiring diagram trying to figure out where to start.
Thanks for your help!
I got a new battery. I also brought it to advance auto test. Tested ok
I also tested with another battery
When I turn on the key voltage drops about .8 volts at the battery. So if I start at 12.4 it drops to 11,5 or so.
Idle at 1200 and battery stays at around 11.6.
Rev to 2000 and voltage might get to 12v.
I checked resistance across main fuse and it is 0 (not started, key on)
I pulled other fuses and voltage does no go back up.
Turn key off and voltage goes back up
The idle is erratic and I wonder if it could be due to low voltage? Idles ok then will surge a bit then back down.
I’m looking at wiring diagram trying to figure out where to start.
Thanks for your help!
