Houtman_imp
Road warrior
Sooner or later a batterie will die anyway , just buy a new one !
Bike crank but wouldn't start.
- Thread starter zirconxi_imp
- Start date
zirconxi_imp
Running like a top
Thread starter
While cranking, the neutral light went out. After few more tries the meter even reset after cranking. I tried jumping using battery from my ninja 650 battery. While cranking, neutral light still went out. Will try to get a new battery tomorrow and try again.
Lord Popgun
Road warrior
Well that pretty much verifies a bad battery. Just the very low cranking voltage does it for me. 8-9v is too low for the ECU to run on most vehicles.
max
Road warrior
Thanks Zirconxi, that confirms the suspicion i had about the neutral light, i found that it dims a bit when the bike cranks but now with your confirmation i think i can say that we can use that indication for a bad battery test; neutral light out = bad battery.
I'm with Popgun and the rest of the group to advice on a new battery.
In the meantime we found a new way to test a battery so thank you very much for that feedback, that was very useful and hopefully we can advice other members of it in the future.
And when you do install a new battery make sure the contact surfaces on the cables are very clean before connecting the new battery, with those 120 amp currents it is important to get all the available energy into the bike.
I'm with Popgun and the rest of the group to advice on a new battery.
In the meantime we found a new way to test a battery so thank you very much for that feedback, that was very useful and hopefully we can advice other members of it in the future.
And when you do install a new battery make sure the contact surfaces on the cables are very clean before connecting the new battery, with those 120 amp currents it is important to get all the available energy into the bike.
zirconxi_imp
Running like a top
Thread starter
Bad news, new battery crank like previously, but still no start, no spark, no fuel on crank, new battery voltage when key on, 12.7v, cranking will drop to 11v, then 10v, release crank n its go back to 12.6v. Neutral light no more dimmed on crank, new battery seems ok. .
max
Road warrior
unexpected indeed, well there is a check you can do on the crank shaft sensor.
No need to remove engine cover but locate the red connector with white and yellow wires under the right hand side cover near the air filter.
The white wire is connected to ground inside the ecu.
with the connector connected use a straightened paper clip to probe the yellow wire through the little rubber seal around the yellow wire, push it all the way in until contact is made and the meter indicates a value of ca.500 ohms.
With the engine and ignition off measure between the yellow wire and chassis ground, there should be close to 500 ohm resistance.
This is the "reluctor"coil, this coil times the spark and injectors, when the engine is running it produces 7 volts ac for the ecu.
So with engine cranking it should produce a little ac voltage like 1 volt or so i guess.
With the ignition switched on but engine off the yellow wire has 0,3 volts DC with respect to ground supplied from the ecu.
Check if the connections are in good shape and not corroded.
here is what the sensor looks like;
and;
And here is how it works;
I don't think that this part is broken but at this stage it needs to be eliminated as a possibility.
Hope that helps.
Just had an idea; are you sure you re-connected the ignition coil wires correctly when checking the valve clearance? they are a bit awkward to get to.
No need to remove engine cover but locate the red connector with white and yellow wires under the right hand side cover near the air filter.
The white wire is connected to ground inside the ecu.
with the connector connected use a straightened paper clip to probe the yellow wire through the little rubber seal around the yellow wire, push it all the way in until contact is made and the meter indicates a value of ca.500 ohms.
With the engine and ignition off measure between the yellow wire and chassis ground, there should be close to 500 ohm resistance.
This is the "reluctor"coil, this coil times the spark and injectors, when the engine is running it produces 7 volts ac for the ecu.
So with engine cranking it should produce a little ac voltage like 1 volt or so i guess.
With the ignition switched on but engine off the yellow wire has 0,3 volts DC with respect to ground supplied from the ecu.
Check if the connections are in good shape and not corroded.
here is what the sensor looks like;
and;
And here is how it works;
I don't think that this part is broken but at this stage it needs to be eliminated as a possibility.
Hope that helps.
Just had an idea; are you sure you re-connected the ignition coil wires correctly when checking the valve clearance? they are a bit awkward to get to.
zirconxi_imp
Running like a top
Thread starter
Thanks Max for the instructions. Will test the shafts sensor. As for the ignition coil wires, i have run about 3000 km since i last did the VC. It did have this intermittent lost spark when hot after i did VC, but its rarely and intermittent, could it means i didn't put the coil cables correctly?
zirconxi_imp
Running like a top
Thread starter
Hi Max, i follow your instruction and it seems there is no ohm value between chassis and yellow cable. But there is some between white and chassis. Is there any way to tell if ecu or crank sensor is having problem? I plug in a copper cable all the way thru the rubber, tested it from the connector pin to make sure its shorted before plug it back. Tested with ignition off, yellow wire and chassis no ohm reading. Crank the bike and the white and yellow wire no voltage.
max
Road warrior
Ok, make one measurement;
1; unplug the connector and carefully measure the resistance between the white wire and the yellow wire of the connector that runs to the reluctor coil.
Backprobing ( with the paperclip ) can be difficult and takes a bit of practice to get the correct result so first test the ohm meter and see
with the two meter leads together if the reading is 0 ohms, then test the coil carefully.
If the coil is broken the reading will be much higher than 500 ohms, we want to make sure we get the right answer because it is important.
Sorry if i tell you what you already know but if we get this wrong it can be expensive,
i have looked online to find examples of defective coils but they are very reliable,
which is why we need to be 100% sure of the results.
1; unplug the connector and carefully measure the resistance between the white wire and the yellow wire of the connector that runs to the reluctor coil.
Backprobing ( with the paperclip ) can be difficult and takes a bit of practice to get the correct result so first test the ohm meter and see
with the two meter leads together if the reading is 0 ohms, then test the coil carefully.
If the coil is broken the reading will be much higher than 500 ohms, we want to make sure we get the right answer because it is important.
Sorry if i tell you what you already know but if we get this wrong it can be expensive,
i have looked online to find examples of defective coils but they are very reliable,
which is why we need to be 100% sure of the results.
zirconxi_imp
Running like a top
Thread starter
Hi Max, sorry but i am not well verse with electric and electronic. Thanks for being patient with me.
When i touch the 2 probing lead of the multimeter under ohm, there's some small value like 0.5 on the right of the meter, when its not touching it show as 1 at the far left corner.
When i poke the 2 probing pin into the socket of the sensor, it maintain as 1 on far left, as though theres no connection. I believe the circuit is open, but not sure if its supposed to be open or close when unplug from bike.
When i touch the 2 probing lead of the multimeter under ohm, there's some small value like 0.5 on the right of the meter, when its not touching it show as 1 at the far left corner.
When i poke the 2 probing pin into the socket of the sensor, it maintain as 1 on far left, as though theres no connection. I believe the circuit is open, but not sure if its supposed to be open or close when unplug from bike.
max
Road warrior
From what you are measuring it appears you are correct, the circuit is open, the coil cannot "generate" the ac signal the ecu needs to determine at what time
the spark fires and also the fuel injection operation, it stops both functions.
These two are exactly the symptoms you have and as far as i can tell this is the only part on the bike that can cause this fault.
But like i said it only happens in very few cases, it seems a robust system that has to operate at hot temperatures that is not good
for the life of electronic parts so the coil is a good solution.
Here is what a reluctor sensor looks like inside;
1= the coil.
2= soft iron core.
3=permanent magnet.
If a ferrous metal moves past the tip of the sensor it generates an ac voltage as a result
of the magnetic field variation through the soft iron core
To verify if the ecu is ok you can measure the connector pin that would have the yellow wire in it.
in my case i measured 0.3 volts dc on it, you may measure a higher value but it shows
that the ecu is connected and the input is working, measured with the key on.
So if you are convinced that the coil is defective then you have to replace it, this coil is used on a wide variety of honda engines, but you need one that has the right type of connector, grommet with right angle rubber boot and correct length of cable to match your bike.
here is a picture of the page with the partnumber seven;
And a link to partsfish for that page, it has pricing and partnumbers;
https://www.partsfish.com/oemparts/a/hon/511a8d6ef870022e4ccd323a/right-crankcase-cover
And what it looks like without the cover and sensor;
It is not difficult to replace it and for someone like yourself that should be simple to do.
There is an opening in the lower crankcase as far as i can tell so maybe the oil is below that level when the bike is on the sidestand but i am not sure, the sight glass with the oil level suggests that
the oil is below the cover and there seems to be no gasket as a spare part.
So some type of silicone sealant appears to be required similat to what you did with the valve cover, maybe someone with a service manual can explain.
the spark fires and also the fuel injection operation, it stops both functions.
These two are exactly the symptoms you have and as far as i can tell this is the only part on the bike that can cause this fault.
But like i said it only happens in very few cases, it seems a robust system that has to operate at hot temperatures that is not good
for the life of electronic parts so the coil is a good solution.
Here is what a reluctor sensor looks like inside;
1= the coil.
2= soft iron core.
3=permanent magnet.
If a ferrous metal moves past the tip of the sensor it generates an ac voltage as a result
of the magnetic field variation through the soft iron core
To verify if the ecu is ok you can measure the connector pin that would have the yellow wire in it.
in my case i measured 0.3 volts dc on it, you may measure a higher value but it shows
that the ecu is connected and the input is working, measured with the key on.
So if you are convinced that the coil is defective then you have to replace it, this coil is used on a wide variety of honda engines, but you need one that has the right type of connector, grommet with right angle rubber boot and correct length of cable to match your bike.
here is a picture of the page with the partnumber seven;
And a link to partsfish for that page, it has pricing and partnumbers;
https://www.partsfish.com/oemparts/a/hon/511a8d6ef870022e4ccd323a/right-crankcase-cover
And what it looks like without the cover and sensor;
It is not difficult to replace it and for someone like yourself that should be simple to do.
There is an opening in the lower crankcase as far as i can tell so maybe the oil is below that level when the bike is on the sidestand but i am not sure, the sight glass with the oil level suggests that
the oil is below the cover and there seems to be no gasket as a spare part.
So some type of silicone sealant appears to be required similat to what you did with the valve cover, maybe someone with a service manual can explain.
GoldOxide_imp
Road warrior
Great illustration share Max.
Lord Popgun
Road warrior
zirconxi_imp
Running like a top
Thread starter
Thanks for great the help Max and Popgun. I had called my area authorised honda sparepart and it seems its a rare item and they seldom stock it and need to preorder. I am thinking i might as well do some dissect on the cable to see if its broken somewhere while i wait.
max
Road warrior
Thanks for the info popgun, very precise, zirconxi you have a good look at that part, the first time i measured it i could not get a reading myself.
The contacts of the coil connector are a bit far into the plug housing and only after using some smaller probes was i able to read the 487 ohms.
There must be a lot of small wire in that sensor to produce 500 ohms.
If the sensor is actually broken that explains the problem, did you actually charge the 3 year old battery before the last test?
The contacts of the coil connector are a bit far into the plug housing and only after using some smaller probes was i able to read the 487 ohms.
There must be a lot of small wire in that sensor to produce 500 ohms.
If the sensor is actually broken that explains the problem, did you actually charge the 3 year old battery before the last test?
zirconxi_imp
Running like a top
Thread starter
I tested it with a new battery. Initially thought battery is the culprits, bought a new one to replace the 3 years old battery.
SportsterDoc
Road warrior
Max, validating your post 26, H-D Sportster CPK testing is very much the same:
Spοrtster crank position sensors are 2 wire units, which may be described as variable reluctance sensors or magnetic pulse gеnerators, etc. They do not have as clean a signal as hаll еffect, but generally more durable (simple coil). As with the hаll еffect, they are typically rated -40 C to 150 C (300F).
Note: This is a sine wave and requires the AC scale
While cranking: ~ 0.3 VAC
At idle: ~ 1 VAC
Static: N/A
Unfortunately, I did not retain the valuable info shared by Popgun, when we were analyzing idle issues.
Spοrtster crank position sensors are 2 wire units, which may be described as variable reluctance sensors or magnetic pulse gеnerators, etc. They do not have as clean a signal as hаll еffect, but generally more durable (simple coil). As with the hаll еffect, they are typically rated -40 C to 150 C (300F).
Note: This is a sine wave and requires the AC scale
While cranking: ~ 0.3 VAC
At idle: ~ 1 VAC
Static: N/A
Unfortunately, I did not retain the valuable info shared by Popgun, when we were analyzing idle issues.
max
Road warrior
Hi Doc, thanks for dropping in, i think zirconxi has a handle on it now, he did all the tests and provided he measured the coil voltage with his ac voltmeter that would indicate the rear occurrence of a broken coil.
He also measured a ( i think ) low ohms value from the white wire to ground which is correct so at least that conductor is fine, the bike ran ok up to that point so i don't think there is more than one fault at play here, i also found some info to support the diagnosis and help him understand the fault, it may also help someone else understand how this system works.
It can be a bit perplexing for some to see what role electrons play in our bikes and how they trundle around in our electrical system, so a little explanation could help here
Think i have read only one occurrence of such a coil failing, seems a reliable system and very easy to check once you understand what makes it tick.
He also measured a ( i think ) low ohms value from the white wire to ground which is correct so at least that conductor is fine, the bike ran ok up to that point so i don't think there is more than one fault at play here, i also found some info to support the diagnosis and help him understand the fault, it may also help someone else understand how this system works.
It can be a bit perplexing for some to see what role electrons play in our bikes and how they trundle around in our electrical system, so a little explanation could help here
Think i have read only one occurrence of such a coil failing, seems a reliable system and very easy to check once you understand what makes it tick.
zirconxi_imp
Running like a top
Thread starter
I had ordered a replacement sensor estimated to arrive in a month or so. Will know if the diagnosis is correct or other thing are causing the problem. Currently only this sensor are the suspect as there's no V reading from the sensor during cranking, and the sensor seems to have an open circuits.
zirconxi_imp
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Thread starter
Hi Guys, do these crank sensor /pulse generator generally the same other than the connection cables?? It seems the CB650 pulse sensor look extremely alike other than the connecting cables and rubber bush slightly different. is there different spec for each Honda motorcycle model? or its just the connection different?
