Bjorn
XS650 Addict
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Elusive electrical problems (solved)
- Thread starter Bjorn
- Start date
Based on those two statement, you have a bad coil. Should read about 4ohms between the two wires.... and open on either wire to ground...case...earth... whatever you want to call it.
You're reading 7 ohms on either wire to earth... should be open.... bad
You're reading an open circuit wire to wire... should be about 4 ohms.... bad
Jim is correct except the reading between the 2 small wires should be closer to 2.5, not 4. A 4 ohm reading is what you want for a points coil. You have a T.C.I. electronic ignition and it requires a lower ohm coil.
Yeah... my bad. I was indeed lookin' at the points section.
Bjorn
XS650 Addict
Maybe my post was a bit confusing. This is the current state of the coil:
primary winding: 2,9 Ohm
Secondary winding including 2 high tension leads and caps: 24k Ohm
If I unplug the two primary leads from the coil (red + and orange signal) I can also measure from ONE of the primary leads to the mounting holes of the coil. Both measure open circuit if the red and orange are disconnected.
If the two primary leads (red + and orange signal) are connected. And i measure from ONE of them to the coil mounting holes, only then will i get the 7 and 10 ohms.
primary winding: 2,9 Ohm
Secondary winding including 2 high tension leads and caps: 24k Ohm
If I unplug the two primary leads from the coil (red + and orange signal) I can also measure from ONE of the primary leads to the mounting holes of the coil. Both measure open circuit if the red and orange are disconnected.
If the two primary leads (red + and orange signal) are connected. And i measure from ONE of them to the coil mounting holes, only then will i get the 7 and 10 ohms.
Bjorn
XS650 Addict
and as a bonus.... yesterday i could just start the bike....
Just a theory: Even though i saw fuel in the filter after i came to a standstill during the test ride. Could fuel be the problem? Maybe after riding for about 7 kilometers I have used the fuel from the bowls and the bike dies...
Just a theory: Even though i saw fuel in the filter after i came to a standstill during the test ride. Could fuel be the problem? Maybe after riding for about 7 kilometers I have used the fuel from the bowls and the bike dies...
That all sounds right, but coils tend to short when hot and go back to reading "fine" when not at work. You are reading the 7 and ten ohms though other components creating a path to ground. the 3 ohms difference between red and orange is the internal resistance of the coil.
Yes Just seeing fuel in the filters is not proof the issue ISN'T fuel related.
Bjorn
XS650 Addict
Alright ill will do another test ride, wait for the bike to die, unplug the coil and measure it.
What about the possible fuel issues.. How can i check for fuel beyond the inline fuel filter which is between the tank and carbs.
What about the possible fuel issues.. How can i check for fuel beyond the inline fuel filter which is between the tank and carbs.
Open a float drain put a catch can under it, run the taps, will it keep up a steady flow of fuel?
I like to use a clean white oil bottle cut to fit under the carb and look at what comes out.of the carbs.
Random thought: A tight valve can act this way.....
I like to use a clean white oil bottle cut to fit under the carb and look at what comes out.of the carbs.
Random thought: A tight valve can act this way.....
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With the ignition off kick the bike over slowly, get a feel for what the compression is like. Repeat when it quits on the side of the road. Does it feel different?
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Bjorn
XS650 Addict
Did some checks yesterday. I checked the valve play:
LHS intake: 0,07mm (0.0027 inch)
LHS exhaust: 0,11mm (0.0043 inch)
RHS intake: 0,06mm (0.0024 inch)
RHS exhaust: 0,10mm (0.0039 inch)
Also checked the fuel supply like Gary mentioned:
Video of the fuel supply to the floatbowl:
LHS intake: 0,07mm (0.0027 inch)
LHS exhaust: 0,11mm (0.0043 inch)
RHS intake: 0,06mm (0.0024 inch)
RHS exhaust: 0,10mm (0.0039 inch)
Also checked the fuel supply like Gary mentioned:
Video of the fuel supply to the floatbowl:
Probably not the issue, but those exhaust valves are a bit on the snug side
exhaust .15mm
intake .07 or .08 mm
Nice video, does your fuel routing normally go below the carbs then back up? A low head gravity fuel feed can be VERY fussy about routing and "extra filters" Run a direct route with no filters or dips in the line, run the petcocks on prime, see what happens. Often as not troubleshooting is about eliminating "possible" problems.
exhaust .15mm
intake .07 or .08 mm
Nice video, does your fuel routing normally go below the carbs then back up? A low head gravity fuel feed can be VERY fussy about routing and "extra filters" Run a direct route with no filters or dips in the line, run the petcocks on prime, see what happens. Often as not troubleshooting is about eliminating "possible" problems.
Bjorn
XS650 Addict
Normally the fuel line runs like you describe: goes below the carbs then back up to the T-split. The video was made on prime, since its the only way i can test it with the vacuum operated petcock. Planning on replacing that by a on/off petcock in the near future. since i rebuild this one last year it seems to keep dripping in ''on''. Not my main problem though 
.
Friend of my recommended to clean the carbs. Maybe I should do that first..?
.Friend of my recommended to clean the carbs. Maybe I should do that first..?
Am I reading this right? Fuel won't run uphill, has to run downhill. It may work for a while, but will need constant clearing of the air and will not be trust worthy. I have this problem on two Honda CB750Cs, short fuel lines and large filter are a pain. Switching to reserve is, pull off the road and blow in the tank. I should try some 90 degree barbs and smaller filters but they aren't available locally. If they were 1/4" lines I'd have them fixed.
Scott
Scott
Bjorn
XS650 Addict
The story continues
I worked on the carbs for the last several days. Did a quick overhaul to make sure they are clean and not causing any problems. I will try to re-route the fuel line and filter, but its going to be tight. According to Heiden tuning it should not matter how you route the fuel line, but ill try it anyways.
I bought two of the plug testeres Garry recommended. But they wont work because they are made for cars and dont fit my plugcap and plug. So I have to return them...
I also made to ''test leads'' for the coil. This way i can check them more easily during or after the test ride. Maybe use an VOM during the test ride ?
And finally i bought a on/off/reserve petcock to replace the vacuum operated one.
I worked on the carbs for the last several days. Did a quick overhaul to make sure they are clean and not causing any problems. I will try to re-route the fuel line and filter, but its going to be tight. According to Heiden tuning it should not matter how you route the fuel line, but ill try it anyways.
I bought two of the plug testeres Garry recommended. But they wont work because they are made for cars and dont fit my plugcap and plug. So I have to return them...
I also made to ''test leads'' for the coil. This way i can check them more easily during or after the test ride. Maybe use an VOM during the test ride ?
And finally i bought a on/off/reserve petcock to replace the vacuum operated one.
I see you're using a Honda MP08 coil? Those are supposed to be very dependable, but shit happens, lol. Bring a spare spark plug along on your next test run. If the bike quits, stick the spare plug in one of the plug caps, ground it on the motor cooling fins and check for spark. That should point you towards electrical (possible coil failure) or fuel issues.
Aren't there supposed to be rubber plugs over the pilot jets?
Yeah I ground the end down on mine to fit in the small clip in the boot. other end works fine spark knows how to jump a bit of a gap.
Old mechanics trick; got a plug fouled out and need to get home? Pull the boot away from the plug a bit, creating a spark gap, this lets the voltage build up before jumping, and the plug will have a high enough voltage to jump the gap instead of bleeding away through the oil/gas on the insulation.
Old mechanics trick; got a plug fouled out and need to get home? Pull the boot away from the plug a bit, creating a spark gap, this lets the voltage build up before jumping, and the plug will have a high enough voltage to jump the gap instead of bleeding away through the oil/gas on the insulation.
Yes, there are supposed to be rubber caps/plugs over those pilot jet mounting holes. Without them, maybe the carbs are flooding themselves out at sustained higher speeds/RPMs? I had the impression that running without those plugs would affect mostly low speed operation, but maybe I was wrong.
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