[GrantM]

Hello:

I ordered and received a cdi for my 1995 tw from partzilla. I seem to have an extra yellow wire. I taped over the end of the yellow wire, held my breath and 260$ cdi but the bike fired up and ran nicely. All the symptoms of idling fine but an inability to rev up appear to be gone.

Does anyone have any concerns leaving that wire disconnected? I guess the damage would have been done by now?

Thanks for any comments.

Grant

 

[FortPayne]

Wait for someone with it fresher on their mind can chime in but NO its not fine. I had wires connected wrong and went over 2,000 before the cdi went taking my stator with it. Very expensive lesson. Don't run that baby til you figure out where it goes.

 

[operose]

Don't cut the yellow wire!!!



Well, you won't blow up but can't remember what it does. Better safe than kicked off the bomb squad the hard way. Will look it up for you in morning if someone else doesn't chime in

 

[elime]

My parts bike came with a spare CDI. The PO said he spent $300 and it didn't run any better with the new one -- it was a carb problem. I noticed the extra wire and decided to use the older CDI with the correct number of wires and after reading this post I am glad I did. I was thinking maybe the yellow wire went to a tach.

It seems like all things TW start with a "2JX", at least on my '87's. If so maybe "2YG" is significant for some other model that is useable with the TW.

 

[GrantM]

Thanks a lot to all who replied. I am trying to find a good wiring diagram but no luck yet. A sketchy one shows what looks like the yellow wire going to a neutral switch.

Thanks again.

Grant

 

[FortPayne]

2yg is my '94 so I assume '88-'00.

 

[FortPayne]

OK here we go. Assuming you have the correct model stator and cdi, the yellow and brown wires go to your stator. They come from the stator and attach to the wiring harness under the seat. It keeps the colors and attaches to your cdi out of another point on your wiring harness. Shouldn't run without it actually. I ran mine with the yellow and brown wires reversed for 2k before utter destruction.

 

[elime]

So what I need is a wiring diagram for an '87.....................or what years have a yellow wire and which years don't?

 

[GrantM]

Thanks for the diagram. I am going to end up with the extra yellow wire I guess since all the other colours matched up nicely....A bit of history... I only had the bike home for a few hours before the idling and rev problem showed up. I isolated it to the cdi after several carb cleans. I noticed the problem went away when moving the bike from a warm to cooler place. II baked the cdi in the oven and could get a ride or two out of it but I never ventured too far. This new one seems to work great but I hope I don't have a 2000 km disaster.

Thanks again

Grant

 

[FortPayne]

So what I need is a wiring diagram for an '87.....................or what years have a yellow wire and which years don't?

Those came right out of the manual downloaded from this site. The first wiring diagram in the manual is for an '87. The pics I posted are from the end of the manual for later model bikes. It's all pretty sketchy at best but through personal experience I know this is the one to use on my '94.



P.S.- Still don't think there should be any extra wires much less a yellow one but if it works then good luck to ya!

 

[elime]

It looks like the one without the yellow wire has a total of 9 wires. With the yellow it is 10.



Edit: I just checked the San Jose Yamaha website. The '87 TW CDI part number is 2JX-85540-M0-00. Then I checked the '88 and '94 model years and they were both 2YG-85540-M0-00. (BTW, It is "emm zero", not "emm oh".)

 

[chainslap]

88 Tw200: Purchased about two months ago. Been sitting for two weeks with electrical problems. Not cool.



While chasing down what seems to be a fried ignition coil assembly I found a few bare wires and a couple of poor connections. I repaired what I found and still had no spark. I checked all relays, switches, connections (except inside the case) and I'm starting to think it is a bad cdi as well. But I'm hopeful it's just a bad coil.



New ignition coil assembly is on it's way. Bought a cheap one just to check. 10 dollars new off ebay. Local dealer wanted 99 dollars.



So while I'm checking everything I notice I have a yellow wire loose in my loom and it shows in my diagram that it should be going into the cdi. But my cdi does not have a yellow wire coming out of it. The wire has a factory looking connector and the diagram shows it should have the connector. I pulled the sheath back on the cdi and nope, no yellow coming out.



What's the deal? Do I have a previously replaced cdi? The wrong cdi? Do I need the yellow to be connected? It shows it going to the magneto on the diagram.



Some photos:

Wiring Diagram

CDI (showing yellow wire from case)

Fried Coil

Any comments, suggestions, or ideas? Much appreciated.

 

[FortPayne]

If you have an '88 and NOT an '87 then you are equipped with the wrong cdi unit. The part number in your picture should start with 2YG-----



If your super -d- duper lucky then it's just the ignition coil. Still you'll need the correct cdi.

Much more likely the stator will be involved. Engine off power off take an ohm meter to the brown and yellow wires coming from your engine case and see if you get a reading. Any reading showing something other than open circuit is a good sign. The manual says check between the yellow and red. That is for '87 only and wrong for subsequent bikes.

 

[chainslap]

According to the vin its an 88. Frame has a mfr date of 10/87. Could it be an early 88 with leftover parts? More likely replaced by a previous owner with the wrong one?



Getting a reading of 50 ohms through the brown and yellow wires coming from the case.



Reckon i'll start searching for cdi's while I wait for the coil. Ill post up when I have more info.



Thanks.

 

[goldenhtr]

According to the vin its an 88. Frame has a mfr date of 10/87. Could it be an early 88 with leftover parts? More likely replaced by a previous owner with the wrong one?



Getting a reading of 50 ohms through the brown and yellow wires coming from the case.



Reckon i'll start searching for cdi's while I wait for the coil. Ill post up when I have more info.



Thanks.

Maybe Chainslap and Tony should swap CDI's. One needs a yellow wire and one does not. Sounds simple to me.

 

[operose]

These guys got it. You've got an extra yellow wire on the CDI because your CDI is from an 88-97 bike. The other dude has an extra yellow wire on the bike because he's using an 87 CDI.



You guys really should swap CDIs!!

 

[chainslap]

I'd swap but I wouldn't trade not knowing for sure if mine functions properly.



So I've got the 2jx, but I need the 2yg?



The new ignition coil did not make any difference. Still no spark.



I hate to dump money into parts that I'm not sure will correct the no-spark issue. Especially a $260 part, which is a fourth of what I paid for the bike.



But this is the cdi part number: 2YG-85540-M0-00 with the yellow wire?



Thanks.

 

[chainslap]

No love for the tdub. New CDI w/ the yellow wire. New ignition coil. New plug. New battery. By-passed stand switch. Repaired several bad connections. Still no freaking spark. WTH?



Can't do the timing light test cause the dang thing won't run. Won't roll start.



I hate to send it to the shop but I'm about to kick it over, pour gas on it and light a match.



Can the clutch switch be by-passed? That's the only thing I can think of that I haven't done yet. But if the bike is in neutral the schematic shows the clutch switch is out of the loop and should fire either way. I've gone through the loom with a meter.



I've got compression. I'm almost positive the carb is fine. Bowls fill and overflow into airbox if overfilled. I've used starter fluid but if I got no spark no amount of ether will make it start.



If no other ideas then I reckon she goes to the shop and I let my mechanic pull his hair out for a bit. Probably something simple I'm totally overlooking. Hope so.



I'll update when I know more.

 

[FortPayne]

Hold up before you drop that match...and for God's sake don't bother with a shop.

Did you check your stator? Test the connections coming from your left side case. If your cdi wasn't right it could zap your stator or other way around. Check ohm resistance between brown and yellow wires KEY OFF. Your looking for resistance, a burnt up stator will show no resistance.



Spark is a clear and easy trail. Starts at the stator. You kick the bike it spins the flywheel which generates electricity in the stator. That electricity goes out the case wires and up to the regulator and wiring harness. Regulator to battery. The harness redirects the electricity to the cdi. From the cdi to the coil. From the coil to the spark plug.



You probably know all that but just follow the trail. If your stator is fine I would tear into the harness and trace the wires to the cdi just to make sure they didn't melt through somewhere.



Keep us updated.

 

[chainslap]

Not sure what the original problem was but all new parts including a stator and she's back in action. The stator was checking out electrically. But after removing the case it had visable evidence of possible failure. Several melted sections. The cdi that came on the bike when purchased was in fact the wrong cdi. Don't know if that fried the stator or vice versa. She's all buttoned up and back in action.



Thanks for the suggestions.