Electricity -or is that electrickery.

[FROSTY:Me]

Thought I'd post this up to get a sorta Generic fault finding guide for bike electrical systems.
Fire away with your advise and Ill edit this post untill its got most of the good stuff in it.
Ignoring the real tricky stuff like CDI's and computerised systems a bikes electrical system is actually pretty simple.
I think of it like a garden hose -ya turn the water on one end and the warter/power is soposed to come out the other. If it doesn't then either A-there is no waterr to start with or B) either by desighn or accident there is a hole in the hose and the power is going elsewhere.
simple stuff-Indicators not working one side -the simplest way to isolate the problem is -swap the positive lead over from the indicator on the other side--if it flashes the problems in the indicator if it doesnt the problems in the wiring to the indicator.
bike doesnt start--Think it through a little-do the indicators /lights work -if not check the battery has charge then check the main fuse.-work backwards from the simple stuff.
this is the stuff and the format I'm thinking of - apply the KISS principle please folks -

[Sniper]

This is bloodt good idea for a thread. Thanks frosty

[scumdog]

It's smoke wot make 'lectric things work, the big thing is you have to contain the smoke, if it escapes the device it is meant to work will conk out.

Next time you have a short-circuit watch what happens - lots of smoke and whatever was working don't work no more 'cos the smoke got out.. (mentioned in another thread yonks ago).

On a serious note:

A simple hot tip (learned by me the hard way) when having electrical problems is to check BOTH ends of the main battery leads and check they are still O.K.
An almost broken through end of my earth strap at the frame end (Not easily seen or reached) caused me to think my battery and or alternator was on the way out - also caused the rev counter to intermittently go berserk while riding along and occasional slow cranking speed when starting.

[FROSTY:Me]

ohh scumdog--the temptation to hassle ya about harleys and electrics--oohhh sooo tempting --lol
Good point though mate.

[scumdog]

ohh scumdog--the temptation to hassle ya about harleys and electrics--oohhh sooo tempting --lol
Good point though mate.

Don't get me going about my Hondas electrics -gargh! the number of times I had to push that turd on a wet day!!!

[Sniper]

My honda is ok, all I can say is.......... Kill switches are bloody horrible things sometimes.

[phantom]

On my Honda now when you turn the ignition off the bike keeps going. You can even take the key out of the ignition. The only way to stop it is to use the kill switch.

[Hoon]

It depends on the what approach you want to take, your skill level and what the actual problem is i.e a real electrical fault or just human error??

Usually you'd start with the easiest and most obvious (i.e. kill switch, side stand etc) and work through them one by one until you run out of ideas....at which point you'd just stand there staring at the bike while scratching your head.

To troubleshoot an electrical fault you really need to take an analytical approach by starting at the business end and working backwards through the process of elimination (or work forward).

- Whip out a spark plug, wind it over and confirm it has spark. Try them all.
- If they don't spark then try a new spark plug as they may have fouled up.
- Still no spark, check the coils are getting power.
- No power at the coils! Check the fuses
- Fuses all good! Check the battery.

This should at least narrow the area and point you in a definate direction. Then you may have to get dirty and check recitifers, wiring loom, CDIs, pickups etc depending on the results of the above.

Also don't EVER assume anything. Work with the facts not hunches. I've lost count of the days I've wasted pulling something apart because I was sure it was the cause when it wasn't.
* Once I did some carb work, bike didn't go afterwards, stripped/reassembled carbs about 5 times before I realised it was an electrical problem caused by fouled plugs!!
* Another time after doing carb/head work, bike ran for 60 secs then died. Thought is was a fuel problem, wasted days pulling shit apart. Ended up the wiring loom had moved slightly, touching the exhaust pipe, had melted through and grounded out a signal wire!!

Another reason I like to work back is that if I get spark straight up then I know it isn't an electrical problem (ignoring weak spark or timing issues) and can look elsewhere without wasting anymore time.

[Sniper]

Keep it simple guys.

[TwoSeven]

Electrics are pretty simple - specially honda electrics.

Basically, there are three main circuits on the bike. Ignition, charging, lights.

The most common problem with starting a bike is flooding it with the choke/throttle and then killing the battery with trying to get it to work. Basically for most bikes, the starting procedure should be no-choke, no-throttle until it catches, then gradually wind it up to 1/4 setting and hold it til the engine settles. The starter circuit on most bikes runs at about 3:1 air/fuel so you only need choke if its really really cold. And by cold I mean measured air tem < 5C - not an aucklander on a chilly day.

If the bike has been standing for a week or more (and is not FI), always use engine start on the air-filter (only need a wiff). It takes the load off the starter moter while the carbs sort themselves out.

Battery, - needs a minimum of 12.5v and perferably 13 or more. If it doesnt, then charge it. If the battery is draining over a couple of days (by more than a volt) while not connecting, then its probably buggered and needs replacing/recovering.

Motorcycle batteries have short duty cycles - they need to recover after use. Its why when starting you should always pulse the starter - few seconds on, few seconds off. If you hold the button down, the load that the starter draws will kill the battery (you can tell, because the neutral light will fade, or the engine sound will slow - it should spin quickly).

For some [old] bikes, the lighting circuit and ignition circuit are linked. So if a bulb blows and the bike wont start, replace the bulb. Generally the lighting circuit is separate tho, you can tell there is a problem the indicators will flash fast if a bulb has gone, or they will flash slow if the battey is drained.

Ignition circuit generally wont go wrong, it normally routes thru a switch, a relay and then to the starter moter and then earth. So there is just the key and the starter button that can cause problems up by the bars, rest of the stuff will be located by the battery. All the starter moter does is spin over the engine and effectively bump start the bike. It needs a shit load of current to do it, so if you battery has been loaded, or your carbs are drained from sitting, or you have soaked the plugs from incorrect starting, it may not be able to cope. So if it doesnt fire after two or three attempts, use engine start, if another 2 or 3 attempts, check the plugs - if they are wet or cold fouled - put the battery on charge.

The charging circuit - the bane of all NC30 owners. Basically, the thing spits out about 150+ amps - there will be a couple of fuses 30amp and 10 or 15amp, then it will go into the reg/rect, then into the battery. You want it to be showing 13.5-14 (pref 14) on the battery when its working. Its byproduct is heat, so the reg/rect needs to be connected to the heatsync directly (no paint underneath) - sometimes the frame may be used instead of a heatsync plate. If the battery is not charging, check electric contacts for discoloring (burning), then check fueses with a multi-meter - dont do it by eyeballing it, a fuse can break with a hairline crack and you wont see it. Then check the battery connections. Note. A battery wont charge until a certain rpm is reached - thats why in the starting procedure above you need to hold the throttle so the revs are about 4k or more, it takes the load off the battery while the bike warms up.

As I said before, the most common problem I know of for bikes not starting is incorrect starting procedure, or running short journies without warming the engine up first.

If you start the bike, you must warm the bike up to 80c water temp (about 400C engine temp). Normally there will be a mark on your temp guage at this point - for honda's its often the start of the line after the white square.

If you dont do this, the plugs will clear/cold foul and while, they look ok, wont work - meaning you'll kill the battery trying to get the bike started. The only fix is usually to replace the plugs. The same problem can occur from running a too high octane fuel and mis-matched temp. plugs.

Those are the main things I can think of at the moment.

[FROSTY:Me]

lets stick to the point here--we will assume there IS an electrical fault and we want to fix it

[sefer]

My bit of input is:

Don't just assume it's something major/difficult to fix and start pulling things apart.

With anything electrical 80% of the time it is likely to be something little. A wire off somewhere, a faulty switch, ect.

Check your connections, get yourself a muliti-meter and make sure the current is passing through the wire/components, and find a wiring diagram of your bike, learn to read it and try to narrow down the possible fault areas.

May not seem to be a great deal of advice, but I use to work in appliance repair and it's amazing how often you'd see people ripping things apart and replacing parts without checking the obvious first (and 90% of the time wasting $$ on a part they didn't need).

[RiderInBlack]

Have got caught out with this one more than once.
Fisrt time it was one indicator not working properly. Would come on and not blonk, yet the other side work no problem. The fault was due to some arse putting a too smaller Watt bulb in that side. Fixed with the right Watt bulb.
Second was my fualt. The little GSXR250's lights were not very bright. It came with two 35/35 watt head light bulbs standard. In my wisdom I put two 55/65 Watt bulbs in their place. Result: Better lights and a flat battery . Solution: use one 35/35 Watt and one 55/65 Watt bulb. Result: Better that standard lights and battery stayed charged (Problem solved)
Moral of the story: Make sure that the electrical part is right for your bike's electrical system.

[TwoSeven]

lets stick to the point here--we will assume there IS an electrical fault and we want to fix it

All you need to know is if its Ignition, charging an lighting. See my above post for how to fix it. Its pretty obvious which circuit will be at fault.

Its a motorcycle, apart from the odd color blind person trying to join the wrong wires, not much can go wrong.

As I said, most people forget to check fuel first and try and fix imaginary electrical problems, apart from that, its pretty obvious most of the time whats wrong. I think perhaps the hardest would be to locate a busted wire - but even that comes down to time rather than difficulty.

Sounds like you want to re-invent the diagnostic section of the clymer/haynes manuals. Its pretty easy to follow - personally I would just scan it and post it up.

[RiderInBlack]

Here a goodie (Suzuki owners should pay special attention to this):

When I had my little GSXR250 inline four, I encounted a engine problem that saw it loosing major power. Took it to the shop (Shaws, fu*ken Mark ). They did a compression test which showed some lost in pistons 2&3 so they told me that it was because the engine valves were stuffed. They also suggested that it was not worth repairing for that bike. Having be told it was the engine, I rung the wreckers and got another motor minus the electrics. Swapped motors and put the electrics from the orginal motor on the replacement. Do you think I could get it to go? No. That's because the real problem was one of the 2 coils had died (only half the engine was working):spudgrr: A common Suzuki problem, I found out. A new coil ex-Japan cost $160. Got a Auto Electrician (good old Bindons) to check both coils and the one that was good died on the testing table:slap: Fu*ken if I was going to buy 2 coils @ $160 each. Rung the Wreckers (Bits&Bikes Hamie). They told me that yes we have a second hand Suzuki coil for your bike @ $60 (which they would not guarantee), but recommend putting Kawa or Honda coils in as they are more reliable. Sold me 2 CBR250RR coils for $80 (which they guaranteed). These fit in the bike sweetly. Bike started. Problem fixed

Moral of the story:

1. Find a shop you can trust. If they are putting you bike down, they will not take interest it helping you fix it (Bloody Mark).
2. Get to know common faults for your bike (or at least use a shop that does).
3. Make sure that you really know what the fault is before you start buying parts (it cost me big time not doing that).
4. Ask as many experienced bikers/bike wreckers/bike mechanics that have owned/worked on a bike like yours about the problem you are having.
5. You can not always find a Workshop Manual for your bike (was not 1 in English for the GSXR250) and you fault is not always mentioned in it if you do have one (if you're lucky it will tell you how to replace the part and how to test it).
6. Every Manufacturer has a common fault in their bikes. For Suzuki, it's their coils.