81 XS650 running but have issues

Excellent opportunity to take out the spark plugs ground them to the cylinder head
Kick it or e- start watch how the spark Looks
 
Ok so valves were out just a touch on right side exhaust.

Have intakes at .0025 and exhaust at .006

Checked my cam tensioner again while running and it’s good still

Checked timing again and it’s a touch on the retarded side but just barely. Maybe about 13 degrees before TDC

Still same issue

I’m rigging up a wire and clamp w/extra spark plug so i can do the dead cylinder test and also check spark on both sides

After that not sure, carbs are set at 3 turns out on the mixture screw, ran well there before so not messing with that yet.

I also need to do a compression test, I’ll have to go to the parts store and rent one
 
Ok so just tried first switching spark plug wires to see if anything changed as far as one cylinder running worse and switching sides. Nothing changed. Then i checked spark both plugs and they seem good. Then did dead cylinder test both sides to see what it did. See videos below.

At this point not sure what direction to go…. Should i do a compression check? Or do you think this is a carb issue?

Right side unhooked



Now left side unhooked

 
Though I’m chiming in here late, I did go back and skim most of the thread. You have certainly done a bunch, some multiple times, to correct the issue. I commend your perseverance.

I did see cam timing discussed briefly, but didn’t see definitive verification thereof – perhaps I missed it. Some of your symptoms are consistent with bad cam timing and this motor will run when surprisingly out-of-time, but it won’t run right at all rpm’s.

Risking redundancy, here goes:

Remove stator & tappet covers,

Rotate crank normal direction while observing left intake valve,

Rotate until intake valve opens and then closes,

Shortly after closing that valve, continue rotation to next TDC of left piston (TDC compression stroke).

Notably, one should use a dial gauge on piston to determine that TDC and not the XS Charge rotor marks: something weird is going on here and those marks are among the suspects. Absent a dial gauge, fashion a rod to carefully insert in the spark plug hole to verify piston TDC. The hole angle will try to wedge it against the piston crown – avoid that.

Remove the right “points” cover,

Observe the R. cam end and locate dowel pin (or hole) on the cam – it must be at 12 O’clock on a line through crank & cam centers. Also note the T mark on rotor and verify it is correct.

Report results for further pondering.
 
Though I’m chiming in here late, I did go back and skim most of the thread. You have certainly done a bunch, some multiple times, to correct the issue. I commend your perseverance.

I did see cam timing discussed briefly, but didn’t see definitive verification thereof – perhaps I missed it. Some of your symptoms are consistent with bad cam timing and this motor will run when surprisingly out-of-time, but it won’t run right at all rpm’s.

Risking redundancy, here goes:

Remove stator & tappet covers,

Rotate crank normal direction while observing left intake valve,

Rotate until intake valve opens and then closes,

Shortly after closing that valve, continue rotation to next TDC of left piston (TDC compression stroke).

Notably, one should use a dial gauge on piston to determine that TDC and not the XS Charge rotor marks: something weird is going on here and those marks are among the suspects. Absent a dial gauge, fashion a rod to carefully insert in the spark plug hole to verify piston TDC. The hole angle will try to wedge it against the piston crown – avoid that.

Remove the right “points” cover,

Observe the R. cam end and locate dowel pin (or hole) on the cam – it must be at 12 O’clock on a line through crank & cam centers. Also note the T mark on rotor and verify it is correct.

Report results for further pondering.
Ok so I’ve done what you’ve said and the pin on the points side is at 12:00 and marks looks spot on.

I’ve always felt like something has been off about my electronic ignition I’ve gotten from MikesXS. But they’ve been cool and sent replacement parts like sent a new coil and new e-advance (blue) ignition. But still have weird issues like right now I’m adjusted all the way advanced on the ignition but my light shows I’m still not quiet at 15 degrees, it’s ran good like this before though. But my last ignition was different in where it let me set timing. Also had an issue with the points side locking part (plate thing) that locks the rod to the cam, it has a through cut slot instead of sealed where the pin is allowing the pin to potentially come free and out (happened once at first).

I feel good that i have some key points looked at though like valve specs, cam tensioner good, carbs cleaned good, and have spark. I’m going to keep checking i think doing dead cylinder adjustment with the mixture screws to see if it just needs some adjusting if not that also need to double check i don’t have a air leak at the throttle shaft on the carbs. So a few things for tomorrow i want to see. Then keep chasing this thing, seems close though but still needs something
 
My bike runs best at about 13degree BTDC I think 5Twins said once,, give or take a degree. these bikes have their own place with regards timing. jetting is complex and your plugs will tell you which way to go i got very good at removing carbs and re jetting . i like what you done keep up the good work well done good effort
All the best funky
 
You've been through carbs and ignition plenty of times - all but eliminating them as cause of problem.

Compression check is in order if only to check-off list. Cam timing is checked.

Cam came in a box of parts, so its origin unknown. It's a stretch, but if you want to check basic cam design (in motor), attached is a printable degree wheel with stock valve timing. Normally, a dial-gauge would be used affixed to read valve stem movement. Perhaps you can devise a way to use it. Link to source if you want to alter or reprint https://www.blocklayer.com/degree-wheel.aspx
 

Attachments

  • degree wheel xs650.pdf
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Oops! I just went back through thread again and didn't see where ignition coils and their source voltage has been eliminated as possible issue. It's best to work this stuff in a rational order and I've got you jumping around. Cam stuff not in order yet.
 
Was reading some comments on Facebook on the xs650 page and seen a lot of complaints about the electronic ignitions coming from Mikes same as mine. Same issue they all said saying when it’s warm it looses spark. I think i had that sorted with the replacement but seems that i have this issue now just wondering if my problem is related somehow to this ignition set up. What is the best ignition you guys think for the xscharge setup? Not that i want to go down that road but just starting to be concerned again about the ignition
 
I've never had any problems with Boyer Bransden on my XS and several other bikes.
 
No Points on the Boyer nor mechanical advance ..
If I may suggest . Please look at the left side spark again .. If it looks weak .. consider to jump power to the coils and ignition
unit Please do the read up if it is allowed and dont leave it turned on connected. It can fry it.
And a separate ground.

Reason being to bypass as much problematic wiring as possible the fuse and holder is good to keep.
Bike ran fine there for a moment .. And for that to disappear on both sides makes me believe electrical.
And those faults can be tricky to find . It is difficult ..
Hook up a voltmeter is also good.
 
Yours is an 81. It came from the factory with a first generation electronic ignition.... the TCI. It's still a damn good, reliable system. The original alternator is also a good reliable system once it's sorted.
If it were me, I'd put the original bits back on it.

Pamco folded up and went dark coming up on two yrs ago now. Not really an option anymore.
 
Yours is an 81. It came from the factory with a first generation electronic ignition.... the TCI. It's still a damn good, reliable system. The original alternator is also a good reliable system once it's sorted.
If it were me, I'd put the original bits back on it.

Pamco folded up and went dark coming up on two yrs ago now. Not really an option anymore.
Good thing i just sent you my pickup a couple months ago… 😂👍🏼
 
So with that one is it a points setup on the one side and the electronic pickup on the other? Mine is a 81 so i guess i would need the points setup
No, with the Boyer, it's fully electronic. The static plate and the rotor plate fitted to the camshaft replace all the points gubins and you get rid of the mechanical advance mechanism too. Easy to set up, then fine tune with a strobe and you never need to touch it again.
 
It mounts up much like the system you've got now, through the cam with a threaded rod. But that rod is nothing more than a length of all-thread they hack off a longer one, kinda cheap in my eyes. Do some research because some of them aren't without their issues. I guess some don't support the timing plate very well and it can warp.
 
Ok so referring to Jan_P request, since i don’t have battery and have that capacitor instead, do i just unhook the capacitor and hook those wires to a battery? Or can i just leave it all hooked up and jump wires from the capacitor to a battery?
 
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