Underdog
Bark Bark
haha 5twins wins...pretty sure the main nozzles are shot took out the spacers under the needles and replaced them with a o rings half the thickness of the spacers and shes runnin like a raped ape 
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stuttering issue - with video
- Thread starter deadchef
- Start date
-
- Tags
- carburetors engine
Bjorn
XS650 Addict
interesting topic, i'm curious about the outcome
Underdog
Bark Bark
deadchef check your batt voltage at 3k rpm it should be 14.5v... bypassed my key switch and brought my voltage back up to 14.77 v at 4k rpm on the highway meter hooked up
...then my shot chain threw a master link had to push it 3 miles home
...then my shot chain threw a master link had to push it 3 miles home
deadchef
xsbobblehead
well, got my carbs back today. i was told that the choke plunger was the most likely culprit. the rubber on the end had swelled. made sense. installed, let her warm up. same thing. won't rev past 5.5k.
since i've been waiting for the carbs to return, i installed a new coil, wires, boots, plugs and even did the magnet trick on the rotor.
what else should i look at? tci box? should i question the carbs still? burn down my shed with the bike in it?
since i've been waiting for the carbs to return, i installed a new coil, wires, boots, plugs and even did the magnet trick on the rotor.
what else should i look at? tci box? should i question the carbs still? burn down my shed with the bike in it?
mrkil
XS650 Addict
do you know anyone with a points set up you can borrow so you can just run it off a battery.
that will eliminate everything else and narrow down the search for the culprit.
that will eliminate everything else and narrow down the search for the culprit.
deadchef
xsbobblehead
unfortunately i don't.
kind of putting together a couple scenarios. all involved basically throwing money at it until something sticks. summer is too short to lose anymore riding time.
1. buy a set of vm's from 650motorcycles.com
2. buy a pamco. although is it difficult to locate the other oddball shit i need since i have tci? isn't mikesxs out of the advancer rod?
3. buy a used tci. not really my favorite choice. haven't looked but i'm sure they're pricey and i'd still be dealing with 30 year old electronics.
Try something, unplug the voltage regulator and do a short test run. See if it still breaks up at 5K.
Never mind, you already tried a new magnet...
Never mind, you already tried a new magnet...
deadchef
xsbobblehead
just gave it a try. no change.
Underdog
Bark Bark
rev it till it stumbles then manually hold the slides all the way open with your fingers be careful not to block the carb opening and if it rapidly jumps in rpm its you diaphragms or slides
Bjorn
XS650 Addict
This may sound stupid but maybe your tachometer is not working correctly?
I have already replaced mine tachometer once, rebuild the drive inside the RH engine case, changed the cable and it's still acting weird. It looks like its working (not bouncing)but after 3500 rpm the meter hardly goes up even if the engine is making a lot more rpm's by sound. Flat out on a long road it goes up to about 5000(on the meter) even if it sounds like i have reached the top. Because it sounds like a rev limiter is kicking in (dont even know if our XS have one haha).
I have already replaced mine tachometer once, rebuild the drive inside the RH engine case, changed the cable and it's still acting weird. It looks like its working (not bouncing)but after 3500 rpm the meter hardly goes up even if the engine is making a lot more rpm's by sound. Flat out on a long road it goes up to about 5000(on the meter) even if it sounds like i have reached the top. Because it sounds like a rev limiter is kicking in (dont even know if our XS have one haha).
Although it's rare, sometimes the inner pipe on the stock double wall headpipes can collapse, restricting exhaust flow. This causes all sorts of weird and hard to diagnose running problems. You've checked pretty much everything else, might as well investigate this.
deadchef
xsbobblehead
i appreciate everyone's help and suggestions with this. i'm sure you're all getting sick of this thread. i know i am!
here is a pic of the inside of the tci. probably was the cleanest thing i've seen that's 31 years old! nothing looked burnt up or melted. sniffed around and nothing smelled burnt. it did look like maybe the thin layer of epoxy that covered all the electrical gizmos might be pulling up but doesn't seem like its catastrophic.
so tomorrow i'm gonna give mr. morse a call and get some vm's shipped. i can't say that's the problem but those were a planned mod anyways. (although much further down the road). if that's not it then i guess i'll start looking at the ignition. I WILL BE RIDING THIS MUTHA BY THE END OF THE SEASON!
here is a pic of the inside of the tci. probably was the cleanest thing i've seen that's 31 years old! nothing looked burnt up or melted. sniffed around and nothing smelled burnt. it did look like maybe the thin layer of epoxy that covered all the electrical gizmos might be pulling up but doesn't seem like its catastrophic.
so tomorrow i'm gonna give mr. morse a call and get some vm's shipped. i can't say that's the problem but those were a planned mod anyways. (although much further down the road). if that's not it then i guess i'll start looking at the ignition. I WILL BE RIDING THIS MUTHA BY THE END OF THE SEASON!
Underdog
Bark Bark
i went back and re read everything and watched the videos again and your videos it doesn't sound like its idling off of both cylinders regularly and the left slide didn't appear like it want to open as good as the right and one plug was darker than the other...how did you sync the carbs?
knap-sack
XS650 Member
Deadchef did you do a compression test yet? I realize the miles are low but the right side cylinder sounded different than the left when I watched your video. Kinda hard to tell with the video.
I feel your pain. I was doing research because my XS was stumbling and I read your post on the filters. Well mine was doing what yours is doing except when I remove the filters it runs good. So I was researching the filters when I read your post.
I feel your pain. I was doing research because my XS was stumbling and I read your post on the filters. Well mine was doing what yours is doing except when I remove the filters it runs good. So I was researching the filters when I read your post.
deadchef
xsbobblehead
i will say it idles a little better since i got the carbs back from oldskool, and it doesn't stay on the choke as long (probably being warmer out i guess). i synced with the homemade yardstick method which seemed to work well IMO. the plugs were very close in color, just basically blackened up.
one thing i forgot to mention. when i push up on the slides, there feels like a slight resistance, almost like the diaphragm feels bunched up or stiff. this is very slight but noticeable. and i only feel it at about 3/4 way up then it's fine.
how 'stiff' should the diaphragm feel? these aren't as hard as my plunger next to the shitter but seem like they are flexible enough.
deadchef
xsbobblehead
yep, did a test with the carbs off and turned over until the needle on the gauge didn't go any higher. came out around 170 and both sides were identical. new gauge. screw in type. i should have made a video of that since i have just about everything else, lol!
when i remove the filters it can at least get past 5.5k. still stumbles though. i've tried uni's and xs pods with the same outcome.
Underdog
Bark Bark
i was thinking maybe the carbs were out of sync still because of the sound difference between the cylinders smell the exhaust at idle is one really rich or lean? ...is it sucking gas into the left cylinder through the petcock vac line i cant remember if you checked for that?
Underdog
Bark Bark
btw i sycnd mine with a manometer and it was still off i had to do it by spark plug color after riding a while and that cleared my 5.5 break up quite a bit
deadchef
xsbobblehead
well i can certainly tell you what the problem isn't! lol
things i've tried to date...
rebuilt carbs probably 4 dozen times (literally) with every jet combination that's plausible. even purchased the canadian needle jet to try to further tune. also sent them to oldskoolcarbs for rebuild. replaced diaphrams.
set valves, cam chain tension
checked timing
great compression
new plugs, new wires, new coil, new battery
xs pods & uni's
tried the radioshack magnet on the rotor
scrapped tci and installed pamco system (very nice by the way. and for everyone looking for the additional advance parts for the tci bikes, bike graveyards can be a savior!)
cut stock mufflers off (5twins and michael morse suggested that maybe something in the exhaust could have collapsed creating hard to diagnose issues. certainly plausible)
another round of jet swapping to compensate for free flowing exhaust. it got better but still there with some odd stumbles. and i just wasn't confident that the problem was gone. only way it would run somewhat ok was really lean and that didn't sit comfortably with me. (like stock mains with no muffs and uni's)
hugh's pma (another very nice system by the way) i just finished up installation. i fired it up and everything is working but haven't really tested it yet to see if my issues are resolved. also tossed on a hotter coil.
the next step is to completely rewire the bike. i've come this far, why not? admittedly i'm not savvy with the electrical diagnostics. slowly testing circuits and connections. i still have the original fuse box and have noticed some bad connections in there. not to mention corrosion in almost every plug. i'm sure that doesn't help the situation. is it plausible that i haven't been getting enough juice to the coil and plugs?
at the end of the day, yeah i'm a little frustrated that i've been doing more wrenching than riding this summer. although i am very appreciative of what i've learned from this board and the experience. i wanted a project and i got one, that's for sure! certainly not giving up. thanks to all!
things i've tried to date...
rebuilt carbs probably 4 dozen times (literally) with every jet combination that's plausible. even purchased the canadian needle jet to try to further tune. also sent them to oldskoolcarbs for rebuild. replaced diaphrams.
set valves, cam chain tension
checked timing
great compression
new plugs, new wires, new coil, new battery
xs pods & uni's
tried the radioshack magnet on the rotor
scrapped tci and installed pamco system (very nice by the way. and for everyone looking for the additional advance parts for the tci bikes, bike graveyards can be a savior!)
cut stock mufflers off (5twins and michael morse suggested that maybe something in the exhaust could have collapsed creating hard to diagnose issues. certainly plausible)
another round of jet swapping to compensate for free flowing exhaust. it got better but still there with some odd stumbles. and i just wasn't confident that the problem was gone. only way it would run somewhat ok was really lean and that didn't sit comfortably with me. (like stock mains with no muffs and uni's)
hugh's pma (another very nice system by the way) i just finished up installation. i fired it up and everything is working but haven't really tested it yet to see if my issues are resolved. also tossed on a hotter coil.
the next step is to completely rewire the bike. i've come this far, why not? admittedly i'm not savvy with the electrical diagnostics. slowly testing circuits and connections. i still have the original fuse box and have noticed some bad connections in there. not to mention corrosion in almost every plug. i'm sure that doesn't help the situation. is it plausible that i haven't been getting enough juice to the coil and plugs?
at the end of the day, yeah i'm a little frustrated that i've been doing more wrenching than riding this summer. although i am very appreciative of what i've learned from this board and the experience. i wanted a project and i got one, that's for sure! certainly not giving up. thanks to all!
