Pe400 Spark Problems

[rohan]

I am currently having some spark problems and need some help.
I started the bike (after a rebuild) on the second kick and had strong spark for about 15 minutes before I lost the spark.

I have put a multimeter to the bike and get the following numbers. (For the record the coil is brand new but the stator and CDI are not)

•I put the multimeter to the stator only i.e. remove the CDI and read aound 50v when I kick it over.

•I hook up the CDI and put the multi on and get around 40V at the coil end of the CDI (with the coil not attached).

•When I hook up the coil and plug and kick it over I may be getting something but cannot feel a shock when holding the plug and cannot see any spark

•I measured the ohms across the coil and get 1.5 ohms across the two small leads at one end and about 11.8 kilo ohms from the high tensile lead to one of the small wires at the other end.

Any help would be appreciated

[rohan]

I did some research and can answer my own question. A CDI multiplies the spark by a minimum of 10 fold. As such the input spark I am receiving at 50v should be coming out of the CDI at at least 500v, therefore I have a bodgie CDI.
The research I did also tells me the ohms I am reading across the coil is about right too, again must be bodgie CDI.
If Luke of Leigh are reading can you confirm what volts I should be reading from the PE400 stator? I have read quite a few good articles on rewinding a stator yourself and it doesn’t sound to hard so if my volts are down I may have a crack at that also.

[frostype400]

I am having a similar issue but I haven't checked mine out yet if you can find a manual buy it because it tells you all the specs you should have.

http://cgi.ebay.com/ebaymotors/Clymer-Suzuki-PE175-PE250-PE400-Service-Manual-_W0QQcmdZViewItemQQhashZitem4aa73f8a66QQitemZ320633539174QQptZMotorsQ5fManualsQ5fLiterature

This is a really good manual I have one of these as well as the factory pe400 manuals.

[LWC82PE]

You should find the PE400 workshop manual (which is better than the Cylmer) here http://groups.yahoo.com/group/PEmotorcycles/ or on Lukes site which is linked from the forum. I Dont know spec off the top of my head. It will be the Primary coil or CDI thats the problem. Thats the main things that go wrong.

To rewind the primary coil you would need to get some wire the same thickness which is really thin and also rewind it the same amount of turns so its the same resistance and produces the same voltage. You can buy the coils brand new though. You might wanna check your flywheel too. If its weak on magnetism the spart will be poor. if it can hold up a 8 inch shifter on its tip then thats a good indication the magnets are ok.

[lukeb1961]

PE manuals are here:
http://cid-407d7ef0965d3991.office.live.com/browse.aspx/Pure%20Enduro/PE%20Owners%20Manuals

ping me a private mail if you want a DVD of the entire PE/RM skydrive.

it is becoming common to see the stator coils need rewinding. OldFart has a contact who can do them for a song.
I would be sending the stator off to get freshened-up before wasting time on anything else. CDI is encased in a block of gunk and is extremely unlikey to be the problem. As you have a new coil...

urm.. a simple thought - your stop button hasn't gunked itself ON ?

Luke

[rohan]

Thanks Michael, Leigh, luke
No not the stop button made sure of that.

[Mike52]

There is a second coil Peter and it triggers the SCR to release the voltage saved in the capacitor.
You are measuring the exciter coil output and the voltage is fine.
What about the trigger coil ? Should be a low voltage. Usually under 5volts.
The trigger coil is laying on top of the exciter coil.
You could ask Frosty to measure the ohms on one of his and compare.
Mike

[Lozza]

To read the trigger voltage you need a peak voltage adaptor, which is a capacitor and diode. A analogue multi is handy also

[LWC82PE]

well according to the test section in the manual

Low speed coil - red/white - black/white - several hundred Ohms
High speed coil - black/red - red/white - several ten Ohms

Then if we look at the specs section at the back

B/R - R/W - 38-48 Ohms
R/W - B/w - 260-325 Ohms

Except for Canada/England (who knows why)

You dont hear of many trigger coils on PE's being faulty

[lukeb1961]

if you recall, Bob had terrible spark until he fixed his coils. Now he has fat blue spark.
Fabrice also had a pulsar coil failing, I seem to recall.

Definately worth getting donef the numbers are too low!
Luke

[LWC82PE]

Fabrice and Bobs were the primary coils not pulsar, well at least Fabrices was just the primary as i have his old one. His pulsar was ok though. Other guys in USA have just had to replace the primary. I got Fabrices old coil to unwind it and get the data on it so we can just wind them ourselves when the day comes that they are NLA as new items. Just looking at it now he has it marked 'HS' (high speed) 120 Ohms which is a high resistance but i reckon he had it marked wrong and it should be LS as the colours dont match my diagrame which are red/white - black/white for the primary but i to what the will admit i took that off a 250 stator and i had a vague suspiscion the 400's colour wires are swapped over on the 2 coils to what the 250 is. Either way you know 120 Ohms is no good.

[montynut]

Using a digital multimeter to try and measure a stator output while kicking over is a hit and miss affair at best as the sampling rate of a digital meter is too slow and all but the most expensive meter do not meausre true RMS values. This is why you will get different readings on multiple attempts to take a measurement. Lozza is partly correct that a peak voltage attachment or option on the meter will help but the only way to be sure is to use an analog meter with peak hold which will give you an accurate true RMS reading.

It sounds like the trigger circuit but I assume since it is a new rebuild you have checked the earth system. Stator to cases, engine to frame, CDI unit to frame and coil to frame. Just a thought because I think we have all been caught out by the earth system at some time.

[LWC82PE]

I got Fluke 87V and its digital with True RMS capability. its my new toy i havent used yet though. For a $840 meter it better be good (thankfully i paid less than half that for it inc shipping, thanks to ebay and the good exchange rate ) Im going to get one of those clamp current meters too to measure higher currents. Next after that will be an ocilloscope.

Alot of people have been caught out with poor earths due to paint on a new build.

[montynut]

The Fluke 87III or 87V are an excellent multimeters with true RMS readings the really difficult problem to overcome with readings at kick speed is the response time or sampling time. While 120ms is of no consequence when reading something which is running on relatively constant it is not really ideal for short duration rapidly changing AC voltage which is far from a sine wave.

I am not trying to say the Fluke 87 is anything but a great meter ( I have 2 one at work one at home  just that its strengths are not ideal for what is being measured.

[rohan]

Just to confuse things more, I thought maybe it was a faulty plug so I got another one and put it in and presto big blue spark! I thought I would put my old plug in to confirm a dead plug and presto again - what the???.
I started reassembling all the bits and refitted tank etc kicked her over and wouldn’t start - no spark...frustrating.

That’s where she currently sits. I will double check all the earth points tonight and anything else I can think of. I have a feeling it’s a stupid little problem and are hesitant to spend $260 on a new CDI to find out it wasn’t that.