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Some gas and a match may be my only option.

........Paul
Don't be a "Florida Man" ,take it out of the garage before you set fire to it!


(for those of you unfamiliar, Florida man and Florida woman are newspaper headline leads for really stupid shtuff people in florida did)
 

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My thoughts exactly, in fact the first wiring diagram that I got indicated that there was an anti theft device utilizing a chip key similar to that used in cars. Turns out that was for a EU model and not the US model. I've by passed as many switches that I can and still crank the engine. Some gas and a match may be my only option.

........Paul
Have to ask but it doesn't say S.A.I.S above the ignition does it? Did the PO have an alarm fitted that was removed? Any sign of a small LED indicator added to the dash anywhere as evidence of a previous alarm?
 

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Something to consider. I don't believe you can simply 'bypass' or jump the ignition switch as there is a resistor in there somewhere as a crude anti theft device.

I'd be disinclined to think the ECU would die without provocation.

Have you messed with the connectors on the throttlebody? There are two that can be reversed.

The one spark symptom is pretty intriguing. If you disconnect any of the associated sensors/safeties, can you get the same one spark condition? IF you disconnect the CKPS do you get a "no spark" condition?
I once had a CKPS failure on a Suzuki product and the symptoms were erratic and the diagnostic tests somewhat inconclusive. You may find a particular input that appears to make no difference when disconnected or connected and that may provide a clue. FULL Disclosure: my CKPS failure was not on a Burgman but on aC50 however there seem to be an amazing number of similar and common parts on these machines.

I probably would not be would not be hugely surprised to find a more recent ECU might be compatible with a K7 generation scooter. Just one more "out there" possibility.

I see that according to the Suzuki Highly technical trouble shooting chart you have reached the replace ECU part of the decision tree. Who knows, they may be right. It probably would not be the first time.
 

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Discussion Starter #44
Have to ask but it doesn't say S.A.I.S above the ignition does it? Did the PO have an alarm fitted that was removed? Any sign of a small LED indicator added to the dash anywhere as evidence of a previous alarm?
I find no indication of any anti theft or modifications anywhere in the wiring.

........Paul
 

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Discussion Starter #45 (Edited by Moderator)
Something to consider. I don't believe you can simply 'bypass' or jump the ignition switch as there is a resistor in there somewhere as a crude anti theft device.

I'd be disinclined to think the ECU would die without provocation.

Have you messed with the connectors on the throttlebody? There are two that can be reversed.

The one spark symptom is pretty intriguing. If you disconnect any of the associated sensors/safeties, can you get the same one spark condition? IF you disconnect the CKPS do you get a "no spark" condition?

******I have found some info that mentioned the resistor, but nothing to fully explain it's location, operation, and testing*****

I once had a CKPS failure on a Suzuki product and the symptoms were erratic and the diagnostic tests somewhat inconclusive. You may find a particular input that appears to make no difference when disconnected or connected and that may provide a clue. FULL Disclosure: my CKPS failure was not on a Burgman but on aC50 however there seem to be an amazing number of similar and common parts on these machines.


****I too have had similar experiences with other bikes. It seems that the Asian manufacturers share many electrical and fuel components. I've been able to substitute a "Suzuki" CKP for a "Yamaha" part. They were identical except for the hardshell connector.******

I probably would not be would not be hugely surprised to find a more recent ECU might be compatible with a K7 generation scooter. Just one more "out there" possibility.


*******I have found out that the early 07 models had a customer satisfaction campaign to replace the ECU and although it has been performed(????), the part number on the ECU is the oldest number in the catalog, not the newer superceded number as expected.*********

I see that according to the Suzuki Highly technical trouble shooting chart you have reached the replace ECU part of the decision tree. Who knows, they may be right. It probably would not be the first time.


******* Haha, yes after going through the 3 step process, I landed at that destination early on in this journey, but I was (very) hesitant to accept that as fact, but as you've "who knows"******

******One thing that I'll add, one of the ebayers that has an ECU for sale has stated that "if your scooter has no spark, maybe this will fix it" Perhaps he's right*********


..........Paul
 

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05c502, you seem very knowledgeable about electrical problems and components and the process of elimination. I'm sure your very perplexed you cant figure out whats wrong and you wont stop till you do. I can only imagine how much this would cost if you took it to a motorcycle dealership to repair. They would be throwing so many parts at it and charging so much in diagnostic time it would make your head spin. I'm sure when you figure it out you will have an "Aha" moment.
 

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Discussion Starter #47
05c502, you seem very knowledgeable about electrical problems and components and the process of elimination. I'm sure your very perplexed you cant figure out whats wrong and you wont stop till you do. I can only imagine how much this would cost if you took it to a motorcycle dealership to repair. They would be throwing so many parts at it and charging so much in diagnostic time it would make your head spin. I'm sure when you figure it out you will have an "Aha" moment.
:grin I worked in the automotive/electrical fields for meny years as a tech, manager, instructor and early on in my career I refused to give up on something until I completely understood it's operation. I've seen too many repairs performed by the shot gun method.

Even at my low rate of 37 cents an hour, I may have already consumed the value of the bike in labor alone.....and it's still not fixed.:frown

That brings me to another point, early on in this thread someone asked what a non running 400 costs. Surprisingly that has yet to be determined. The PO is a friend of mine and we agreed to value the sale after I get it running.:serious

.........Paul
 

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Some gas and a match may be my only option.

........Paul
Please don’t get discouraged with the Burgman Line altogether .... I appreciate your tenacity, and your methodical method of trouble shooting. No mater the outcome of this B400 please consider bringing your powers to the B650 camp.

Here are a couple sites that I hope helps you find yourself on a early version of the B650 :

http://www.max.grenkowitz.net/?topic=786

https://sites.google.com/site/testburgmancenter02/diy---maintenance-guides
 

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I believe the resistor is physically part of the switch. It is there to prevent breaking the ignition switch and simply jumping around it to hotwire the scooter.
 

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Picture is blurry but here is the resistor.
Ign 5.JPG
 

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Discussion Starter #52
Picture is blurry but here is the resistor.
View attachment 87043
Thanks for posting the picture. I've been searching for information on the resistor, but haven't found out much. The manual has very limited amount of information about ignition switch and makes no mention of the resistor. Here's what I know, there are three sets of contacts in the switch, these circuits are open when the switch is off. Two of the circuits provide power to the engine controls and lighting system. The third, when turned on, provides a ground to the ECU. This is the circuit that has the resistor in it - no mention of it in the manual. My switch seems to be working correctly including the resistance in the third circuit. But, and that's a big but, I don't know what the proper resistance should be. Mine has resistance, but it may not be the proper amount. Anyone have any idea? Or anyone want to tear theirs apart and check it?:wink

.......Paul
 

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Discussion Starter #53
I just stumbled onto this little tidbid, it's from an old post on a SV650 site: "The resistor is a 100 ohm resistor and it sits in the ignition barrel between (IIRC) the middle 2 contacts, which are the orange/red to black/white as per RobW's post. It's not shown on any wiring diagrams, and without it the CDI won't produce a spark."

The wiring colors match and unfortunately my resistor measures out to just about 100ohms.

........Paul
 

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<<<SNIP>>>


Anyone have any idea? Or anyone want to tear theirs apart and check it?:wink

.......Paul

I took a better picture. It has Red-Black-Red and Gold bands and that is a 2K ohm with a good tolerance rating.


20200122_135747.jpg
 

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and of course continuity from the resistor to the ecu?
 

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I would start with the simple things. Plug caps on the 400 can be problematic as they are a spring catch and can come off causing a poor connection. Check the coil resistance and the ignition lead. ECU' s are pretty robust. Battery needs to be in good order. New spark plug? Are there any fault codes showing or have you checked these. Could be a faulty cam position sensor or bad connection to the sensor. If you can list the things you have done we can tick off the list.
Welcome by the way lots of knowledge on here so keep asking questions but we are like computers you only get out what you put in so the more info you impart the better
I was going to list everything that I've done in the first post, but it was getting a little long. There were no trouble codes until I started testing/disconnecting things. I started with the simple things, moved to the more complicated tests, and then out of frustration, tried silly things.

Here's what I've done:
replaced spark plug
replaced coil
replaced spark plug cap
checked safety and fuel pump relays
checked fuel pump
checked CKP sensor output and resistance as per manual
by passed the start and kill buttons
disconnected ect,tps,stp, etc sensors
installed a redundant ground between battery and engine
replaced battery
checked/cleaned connections to ecu/ckp sensor
checked connections at the TO sensor

According to the manual, the ignition system include the CKP, ECT, and TPS as inputs and the coil/spark plug as outputs. All check out OK. The control to the coil is provided by the ECU after receiving the CKP signal. I can't figure out why there is only one spark if the CKP signal continues as long as the engine is cranking.

I'm not sure how the TOS operates and the manual offers no test, but it appears that it doesn't affect the ignition system, it shuts the fuel pump down if the bike falls.
I've probably missed a few things, but please don't be afraid to make suggestions, I'm willing to try anything.

thanks
............Paul
Going back a step you have as noted installed a redundant ground between battery and engine. Now the engine is mounted on bolts with rubber isolaters on the 650 to reduce vibration. Possibly the same on the 400. However galvanic corrosion on any bolt reduces a good ground. I appreciate it also mates with the swingarm etc but these are not good grounds. Suggest that you get a good ground to the frame and ECU from the battery as there is well documented issues of people fitting after market lights which ground to the frame then have issues as the earth is bad. A ground from the battery direct to the lights solves the issue. May be nothing but it eliminates yet another possibility. You have nothing to lose by doing it apart from 37 cents or less
 

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I had a vehicle where the spark was generated just once- when the ignition switch turned on, the plug would go snap once, then never again until the ignition switch was turned off, then on. The problem was that the Crankshaft Position Sensor (CPS) was faulty- its resistance was OK but its magnetism was lost for some reason. CPS's have a permanent magnet core; when a little tab of ferrous metal on the flywheel goes past it, changing the B field in the permanent magnet, it induces a voltage in the windings around it. The ECU reads that pulse and determines with some magic software how much of a delay after the pulse that it will discharge its capacitor into the coil, causing a spark. So you could have a defective ECU or a defective CPS.

The CPS is best tested using an oscilloscope- look for positive pulses of 3 to 8V followed by negative pulses of 3 to 8V at the rate the engine turns over. A less accurate method is using a peak-holding multimeter function and look for 3 to 8 Volts while cranking. The CPS resistance test is the least accurate- it tells you whether the CPS windings are intact, but doesn't tell you whether it actually works or not.

Another possibility is that the ECU is capable of creating one spark, but it just can't do another for some reason. ECU's have a voltage multiplying circuit in them, which take the 12V of the battery and chop it up to 300-500V, which gets stored on a capacitor. When the ECU triggers the capacitor to discharge, all that energy is applied to the coil, which multiplies the voltage further to the 30,000 plus volts for the spark plug. A lot of stuff has to be working correctly in the ECU to make this happen- the voltage multiplier has to run rapidly enough that the voltage on the capacitor gets to its 300-500V value between sparks, and the trigger has to be applied to the switch that discharges the capacitor, and the switch has to turn on fully, then it has to turn off while the capacitor charges again. So it could be that the voltage multiplier is too weak, or the switch never turns off after being triggered. Either way, the ECU needs replacement, because you can't fix these things.

SO- check the CPS, then if that's OK, replace the ECU.
 

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Discussion Starter #58
Going back a step you have as noted installed a redundant ground between battery and engine. Now the engine is mounted on bolts with rubber isolaters on the 650 to reduce vibration. Possibly the same on the 400. However galvanic corrosion on any bolt reduces a good ground. I appreciate it also mates with the swingarm etc but these are not good grounds. Suggest that you get a good ground to the frame and ECU from the battery as there is well documented issues of people fitting after market lights which ground to the frame then have issues as the earth is bad. A ground from the battery direct to the lights solves the issue. May be nothing but it eliminates yet another possibility. You have nothing to lose by doing it apart from 37 cents or less
Thanks for the suggestions, but I have added grounds to everything that could be grounded. I used some old wire that I found laying around the shop, so no cost there, but way more than 37 cents in labor...........I'm a really slow worker.:smile

...Paul
 

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Discussion Starter #59
I had a vehicle where the spark was generated just once- when the ignition switch turned on, the plug would go snap once, then never again until the ignition switch was turned off, then on. The problem was that the Crankshaft Position Sensor (CPS) was faulty- its resistance was OK but its magnetism was lost for some reason. CPS's have a permanent magnet core; when a little tab of ferrous metal on the flywheel goes past it, changing the B field in the permanent magnet, it induces a voltage in the windings around it. The ECU reads that pulse and determines with some magic software how much of a delay after the pulse that it will discharge its capacitor into the coil, causing a spark. So you could have a defective ECU or a defective CPS.

The CPS is best tested using an oscilloscope- look for positive pulses of 3 to 8V followed by negative pulses of 3 to 8V at the rate the engine turns over. A less accurate method is using a peak-holding multimeter function and look for 3 to 8 Volts while cranking. The CPS resistance test is the least accurate- it tells you whether the CPS windings are intact, but doesn't tell you whether it actually works or not.

Another possibility is that the ECU is capable of creating one spark, but it just can't do another for some reason. ECU's have a voltage multiplying circuit in them, which take the 12V of the battery and chop it up to 300-500V, which gets stored on a capacitor. When the ECU triggers the capacitor to discharge, all that energy is applied to the coil, which multiplies the voltage further to the 30,000 plus volts for the spark plug. A lot of stuff has to be working correctly in the ECU to make this happen- the voltage multiplier has to run rapidly enough that the voltage on the capacitor gets to its 300-500V value between sparks, and the trigger has to be applied to the switch that discharges the capacitor, and the switch has to turn on fully, then it has to turn off while the capacitor charges again. So it could be that the voltage multiplier is too weak, or the switch never turns off after being triggered. Either way, the ECU needs replacement, because you can't fix these things.

SO- check the CPS, then if that's OK, replace the ECU.
Thanks. I'd love to have scope, but for some reason when I retired, they wouldn't let me take it with me. After doing resistance checks I also was able to do a dynamic test using a voltage averaging adapter and it came in right on spec. I like your explanation of the ECU operation and the longer I work on this thing, I'm leaning towards a bad ECU.

......Paul
 

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I took a better picture. It has Red-Black-Red and Gold bands and that is a 2K ohm with a good tolerance rating.


View attachment 87045

Chapman pointed out to me that the colors on the resistor is more Brown-Black-Brown and that is 100 Ohms. The gold band is saying it is held to 5% tolerance so 95 to 105 Ohms.


I will open the new replacement unit I have on the shelf and take a picture.
 
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