Welp, this morning as I arrived to start my bike for the poker run here on island my bike refused to turn over.
I tried push starting in several different gears and that didnt work.
I tried to start it so many times I eventually ran the battery down. Hooked it up to the car and still no luck.
Unflooded the engine and bought new spark plugs, threw them in and, no luck there either.
Tried to ground out the spark plug on the frame and noticed that it was not arcing out. 1 thru 4 were no go.
Removed the coils to take them to the mechanic thinking he could somehow test them. Haha! Not....
Then the owner of the shop shows up and suggests that it is most likely the CDI seeing as all 4 are out.

Is it common for a CDI to just go bad after two days of sitting? I was riding around 2 days ago to get used
to the new rear shock and rebuilt forks and everything seemed fine. Turned over fine and didnt sound like
anything was wrong. Now all it does is sit there and crank forever.

The shop says its going to be 55,555 Yen for a new CDI from Suzuki. I dont have a problem with ordering a new
part I just want to exhaust all my avenues of troubleshooting before spending almost $700 on a new
computer.

TL;DR - Is there a way to troubleshoot the CDI or coil packs before spending big money on a new CDI?

As a sidenote, the left forward turn indicator just stopped working as well. The right forward has been out for
a while but both bulbs are good. I cant find any breaks in the connections anywhere so I am assuming the
relay is bad but how would I check it? Where can I find a new one? Im getting boned on the exchange
rate over here so something other than Yen prices would be preferable. Man the Okinawans love their bikes!

You can do some simple checks yourself if you have a test meter.

Other things that could cause no/weak spark are bad connections, seeing as you have problems with the indicator this is the first thing to do.

Check black/white return wires.
12v at the coils.
Check the trigger pick up, wires come from LH case, should read around 100 ohms.

Being in Japan you have an advantage over the rest of use as you can buy a workshop manual from yahoo and actually read the test.

Variablevalves suck wrote:You can do some simple checks yourself if you have a test meter.

Other things that could cause no/weak spark are bad connections, seeing as you have problems with the indicator this is the first thing to do.

Check black/white return wires.
12v at the coils.
Check the trigger pick up, wires come from LH case, should read around 100 ohms.

Being in Japan you have an advantage over the rest of use as you can buy a workshop manual from yahoo and actually read the test.

When you say the black/white return wires, do you mean the wires that plug into the bottom of each coil?

By 12V at the coils Im guessing touching one of the connector points and grounding it through the wire for the spark plug?

Im sorry about the extra questions Im not an electrician!

I tried ordering the manual from Suzuki and it was going to be big money and an unknown wait time as they had to make another book for me. So any future orders are to be made to order. Might change my mind on ordering it though. Maybe folks around here could use it?

There are loads of manuals on Yahoo auctions.

The orange wire on the coil supplies 12v, so connecting a test meter between the orange and the frame should show 12v.
The other wires on the coil supply a pulse from the cdi via the trigger under the L/H case.

If you follow the wire from the L/H case you can disconnect it under the seat and test between the two wires, when you test the trigger side (not cdi side) you should get 90 to 110 ohm, any more or less and the pickup is faulty.

The black with white trace wires are returns.

Welp, update time.

I went to order a new cdi yesterday and there were several people talking to the owner of the shop. He speaks really good english so we started talking about my dilemma. This is the same man who told me that it was most likely my CDI acting up in the first place. He mentioned I go check one of the junkyards offbase to see if they had a spare CDI sitting around for my bike.

Went to the junkyard talked to one of the workers about my CDI then he went back around the corner to talk to his boss. He comes back with the boss and the boss is holding a split open Suzuki CDI that looks identical to mine. So he then tells me to bring the bike in and they'll essentially split open the case on the CDI and try to repair it. 10000yen if they fix it, 1000yen if they dont. Far better deal than the 55555yen for a new computer if I dont have to.

Sorry Valves, Im mechanically inclined just not with a multimeter. Rather just let the shop sort it. Im leaving the island in about 2 months and headed for the States so I want to get it fixed and ready for TMO.
Hopefully Ill be riding my 400R in NC within the next 6 months.

And also as a side note, since the bike was half way torn apart when I towed it to the shop the mechanic started looking at it as soon as we rolled it off the truck. He started looking at the rectifier immediately and told me that it was installed upside down, and that this was a bad thing. Ive never touched it so I didnt know any better but apparently the wires coming out of the rectifier (about 5 or 6 maybe?) are supposed to be on the bottom. If not water will collect inside the rectifier. My gasket thing holding the wires together was still intact and there but the mechanic and the owner seemed to think that maybe my rectifier was the reason everything is acting up. Resulting in an overcharging situation. That would maybe explain the front indicators not working. And sometimes it takes a while for my headlights to come on or not at all. Funky electrical problems on this bike but I refuse to give up.

I also noticed the other day that there are two connectors sitting next to the headlight connectors not connected to anything. Nor anything available for them to connect to. 2 wires on each and they terminate right next to the headlight connectors. Im not sure of the wire colors off the top of my head but does anyone have anything similar going on?

Phew, that was a bit but Im done for now.

Aaaaand its done. Turns out the pulse generator went bad so the mechanics replaced it. Total cost is 6000yen.
Back to riding!

That's a good result! After reading about your other problems I think you should check all the earthing points and the connector plugs, spray some contact cleaner into them and that should help.
Hope it all goes well.