Zero Spark

[Vanishing_Point]

You may remember me posting a few months ago about a my bandit that wouldn't start, and first of all I would like to thank all that helped me isolate the problem (damn carbs!).

Anyway, after a blissful month or so getting to know the bike (my first ) and bombing round the Scottish highlands it seems another problems has raised it's ugly head.

Last night I was ready to go out for a ride; started the bike, need some choke so it's revving at about 4k for a minute or so, switched off the choke and it spluttered out (sometimes does). Normally hitting the ignition again starts the engine instantly, but not this time. it cranks over and over yet the engine will not catch (strange as it started fine a minute before). I also notice that when cranking the engine the tacho (rev counter) is not flickering like it normally would when trying to start the bike. At this point I was royally pissed as I knew i have some kind of ignition problem.

Took off the tank, pulled the plugs and did a test for spark on both coils (holding them to the engine casing and hoping to see some sparks) yet no spark appeared at all. I have gathered from this forum that CDI problems are commonplace with this bike so would I be right in thinking thats the source of my woes??

So is a new CDI needed do you think? Also concerning the lack of tacho flickering, would this stop if the coils are bad (doubtful imo as both are not producing spark, yet they did a moment before) or is it just a CDI thing?

This is a especially shit as I was hoping to make the long ride down to London this week. Any help would be much appreciated as always!

[pmackie]

Before you start replacing ignition parts, start with simplier things first. (I'm not familiar with the B4, so some of these may not apply.)

1. Ignition stop switch on right handlebar. Make sure it's on, and make sure it works.
2. Sidestand switch. As above.
3. Make sure the battery is charged and in good shape.
4. Check for any blown fuses.

Are you sure it's an electical issue? The way it stalled (turning the choke off) it sounds like a fuel issue.

[Herr Tod]

You're right about the tacho, best 'tool' to find out if it's ignition related.

Measure if you have resistance at the pickup. There's a cable coming out of the left engine cover, follow it until you find a connector. Measure resistance between the two wires that go to the engine cover. Should be about 100 ohms.

[Vanishing_Point]

1. Switch is in the correct position; starter motor cranks, doesn't when switched off.

2. I've made sure the bike is in neutral, and tried starting with the stand up.

3. The battery is charged and gives a good strong crank.

4. Where would these fuses be located? I checked the ones behind the battery (I assume these are for the lights?) and they are fine? Are there any other fuses I should be aware of?

What worries me is that there is no spark from either coil 

I suppose I should invest in some kind of electrical analyzer (lol what are they called?) then Herr Todd?

Thanks for your help.

[andrewsw]

a multimeter is your friend. Probably an inexpensive one will probably be more than adequate for most jobs on the bike. ANd then you can start troubleshooting old electrical equipment too! 

[camarobandito]

hi vanishing point, sorry to hear problem good thing it didnt happen in the middle of your trip leaving you stranded! What you described about the tach needle not raising does sound like an electrical ignition problem. Andrew couldnt have been more right about getting a multimeter, a cheap one will do just fine make sure it can read ohms.A 12 volt test light is handy to have also. As for testing for spark, like you did with the plug on the engine case, try doing that with the plug against the frame or another grounded steel part of the bike as aluminum doesnt conduct electricity. After you get the multimeter check the tabs where the wires go on the coils, then check plug wires with the ohm meter. Also make sure your plugs arent fouled. Let us know the results of the tests. I doubt very much that your igniter box is blown, always start with the simplest (and cheapest) things first. IMHO I think your coil for the #2,#3 cylinders is bad and your plugs are fouled but thats just my 2 cents. Do your tests before you replace anything and let us know!

[Herr Tod]

aluminum doesnt conduct electricity

Excuse me? It's used in electrical wiring next to copper because it's lighter lol

[interfuse]

Check all the connections. And don't forget the pickup wires.

[camarobandito]

 :duh:My apologies aluminum DOES conduct electricity but is not magnetic  I dont know what I was thinking  I should probably get some decent sleep before I give people mechanical advice sorry!

[gsxr400 racer]

I have one pick up coil hanging on the wall

[Vanishing_Point]

Ok, so I have got myself a pocket tester and have been looking at the electrical section in the manual which tell you how to test the various part of the ignition system.......but I am a bit lost.

Regarding the whole side stand/neutral safety system, am I right in assuming that the starter motor won't crank at all if there is a problem with it, or will it not spark (my problem!).

Also, I located the pickup coil and found the plastic coupling thing......i pulled them apart, but which bit do I measure and what setting do I use on the multimeter? I tried a few of the ohm setting on both the wires that lead into the bunch of cables and the wires that lead to the left engine casing........both were reading 1 (is that infinity? if it is according to the manual that means mine is busted yes?).

I'm at a bit of a loss here guys!

[gsxr400 racer]

wires to the motor 2 set meter to 10 ohms should read 100 ohms plus or minus 20%

[andrewsw]

or in english... 

you are trying to test the resistance across the pickup coil. Resistance is measured in ohms. You put one tester lead on one of the p/u coil connectors and the other lead on the other connector (the connectors should be disconnected for this!). Set your test to measure ohms (it's the greek letter Omega). It's possible that you will have multiple settings for ohms (mine doesn't...  ). Pick the setting that will measure 10's of ohms. Might be marked 10x(omega). Do not use one of the K(omega) settings as those are thousands of ohms and won't register what you need. Finally, on the display (dial or digital?) you can read the result. If it's a dial type. there are several rows of numbers for measuring different things. At least one should be marked for ohms, and you may have to do the math (10x, for example). You are looking for a reading around 100 ohms. anything outside of 80-120 ohms is a problem.

And as to the sidestand switch. If you can crank the engine, it's working (or disconnected like mine is... ).

hth

A

[gsxr400 racer]

anything out of 100 once hot turns to shit glad you had time to type a novel

[Vanishing_Point]

Ok well I have tested the bastard and it's not getting any resistance or even continuity, just reads 1 (means open circuit doesn't it), so in other words it's knackered!! Need a new one then.

Also, I took the side engine casing off to have a look at the think and could not for the life of me undo the 3 screws that hold the pickup in place. They were made of the softest metal ever.....just ended up rounding the buggers! I'm gonna try a hammer and a flathead tomorrow to see if i can shift them.

So, if the pickup is broken, which mine evidently is, this would cause lack of spark yes? So hopefully replacing this would sort me out fingers crossed. What do they normally go for?