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Discussion Starter #1
Sounds familar,no?
Ok,here are the details-the TW is an '89 model,stock electrical system,functioning properly when disassembled a few months back for this project/ rebuild.
Now,while the electrical system is stock,I am using only the magneto portion for ignition-no battery,E-start,T-signals,etc. Based upon everything that I have read about this electrical system ,it is quite similar to the same set up Yamaha used in their RDLC two stroke twins(250+350),of which I have owned quite a few.....

My strategy here was to leave all of the charging coils in tact,inside the case,and use only the coil(s) required to feed the ign. coil and CDI unit,along with removing the various safety switches that are on the bike,which would require leaving those individual circuits either 'open' or 'closed' depending upon the circumstances.
Next, the entire wiring harness is intact,un- modified at this point,because I first want to confirm the running properly before paring away the unnecessary wires,leaving only those required-nothing has been 'hacked',yet.

I've measured the resistance of:

Ignition Coil-
Primary-1.1-1.2 Ohms
Secondary- 16,810 Ohms

Magneto-

White/green wires(drives ign. coil)-835 Ohms
Brn/Red wires(drives CDI unit) - 0 Ohms
Brown wire to Earth- 0 Ohms


In measuring the output voltage of the Orange wire(to ign. coil)-0 volts


Also-
I believe that the following original,now unnecessary circuits should be left 'open'(not jumper-ed or grounded)

Neutral switch
Sidestand switch
Engine Run switch

My reference material is the illustration '7-5' of the Yamaha TW200 Service manual,which shows(only) the entire ignition system circuit.I am using a Fluke 115 multimeter.

Finally,again,I am attempting to use only the major components(ign. coil,CDI unit,and the relative portion(s) of the flywheel magneto),which sufficient enough to allow normal operation-so,I have a component problem,I believe....

Thoughts? Suggestions?
 

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check wiring on cdi and ground circuit, but first check to make sure your spark plug wire is securely attached to the electrode (spark plug cap) I had to cut and rescrew it back onto the wire and made the difference for me. its almost always the simple things and the last one you check (duh). Good luck!
 

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Sounds like you know pretty well what you're doing already..

I had no spark once. Went through the entire system, took the stator out, everything. Turned out to be the kill switch wire that I'd forgot to plug in.

You mentioned that you believe the side stand switch circuit should be left open? I'm not very experienced in electrical terms so forgive me if I don't understand, but to bypass the side stand switch you need to close it. Although if you are in neutral it shouldn't matter.

Zack
 

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On re-assembly it is possible that the magneto cover pinched or cut into the wire harness. The routing of the ignition harness is critical and is illustrated in the service manual.

Don't ask me how I know.
 

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Discussion Starter #5
At this point,I believe 'trigger coil' is likely faulty,given it's zero readings. The red/brn wires are the' source coil',which drives the CDI,I think.That leaves the yel/white wires,which are ac output,going to the rectifier/regulator to become a dc voltage source for battery,etc. The remaining wires-,white/green, relate to the 'trigger' coil. The manual information is very vague,the illustrations poor at best.
Worst case would be the CDI unit itself having failed;best case would be that I missed a connection(Zack-I believe you're right,the sidestand system should be jumpered to mimic the closed circuit as when the stand is 'up'). I believe that both of the mentioned coils can be easily rewound,and if I have to have this done,I will removed the ac charging coils/lugs from the stator frame.
I don't think that anyone mfg's an entire aftermarket ignition system for the TW. After all,this OEM system is 25 years old....
PS- I neglected to mention initially that I did in fact get a 'jolt'(screwdriver in the plugcap 'test') ONCE,then nothing since.......
 

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Discussion Starter #7
Thank you,goldenhtr. Unfortunately,none of those excellent examples relate to my particular TW,as they are Euro models. Having similar for my non-CA '88 would be very helpful.
This 'journey' has been interesting,certainly not fun,tho. In searching the 'Net,I've found a fair amount of information;in old/other forums,etc. Unfortunately,there are voids and contradictions in the information shared by those trying to sort out the problem(s) and help others. Judging by the significant lack of CDI problem related threads and responses,this is clearly not a topic that many TW owners are adept at.....self included. No one opens this can of worms voluntarily.I am gaining an education,tho. At this point,I believe that the source and trigger coils are functioning properly,and,I've negated the various 'safeties' correctly,which leaves just one component(CDI). If that is the situation,then either obtaining a used functioning unit,or replacing the entire system with an after-market unit that I have found are my options....I'm certainly not paying $300++ for a new OEM unit.
(My TW is an early '88,the 772nd bike built for US market,with the 2nd generation 10 wire CDI box.(2YG-MO).)
 

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Discussion Starter #8
NEWS FLASH! UPDATE-
Upon checking the values of the various components once again(after making minor repairs to nicked wires,etc.) The source coil(red& brn wires) reads '0'. I still plan to check my CDI unit momentarily replacing it with a known functioning unit,but this reading of 0 is a show stopper by itself.....
 

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NEWS FLASH! UPDATE-
Upon checking the values of the various components once again(after making minor repairs to nicked wires,etc.) The source coil(red& brn wires) reads '0'. I still plan to check my CDI unit momentarily replacing it with a known functioning unit,but this reading of 0 is a show stopper by itself.....
I don't know if I'd connect a known good CDI to that...
 

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Discussion Starter #10
I agree,rbm,I'm first going to replace the source coil......The CDI unit is a real 'piece of work',based upon what I've been reading about other's woes....some (temporary) remedies include freezing the unit(to confirm it's failure at room temp). It wouldn't surprise me if someone claims to have fixed theirs by chanting while tossing chicken guts over their left shoulder......:D That IgniTech unit is looking better and better!
 

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I'm not sure where it came from but I suspect the CDI from my 87 bought earlier in the year is not a TW CDI because the wires did not all match the diagrams and there were a few extras. My point being, maybe there is another CDI solution from another bike so you could possibly acquire used. I can take some photos and see if there are any markings if you would like. I had to wade though the entire harness and all switches as some Ahole PO thought it would be better to cut it all up and hack out the dash and all lights and left it quite a mess. Oh and I did have to make a blood sacrifice to get mine running but it was the carb! LOL


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Discussion Starter #12 (Edited)
I've considered what you've suggested,hellwig,as I happened across a write-up by a fellow who used TTR125 components simply because of their(much better) availability. He was successful......So,there are at least 4 options for me; 1) have the source coils rewound 2) use the IgniTech system 3) wait until a used TW stator wanders by 4) purchase a new stator. Right now,I'm pursuing #1,with #2 as my next step. #3 isn't likely,and before I select #4,the 'Retro TW' will serve me as an excellent door stop/dust collector/static display(yeah,I'm that hard headed). Your suggestion is a 5th option.
This whole situation would have been much easier had all of the information that I've collected been composed under a sticky or whatever allowing a person to find much more easily. Oh well.....

I've spoken with 3 motorcycle rewind businesses -all have stated the difficulty(or, actually,the impossibility) in duplicating the exact electrical output value of the factory;and this is critical to prevent over-driving (damaging) the CDI unit. Knowing the wire gage and ohm rating range are the only knowns,how many turns used by the factory isn't.....so there is a risk. Enough of one,that these businesses aren't interested in attempting a rewind;and,I can't blame them.
Rewinding a charging coil has the 'safety net' of having a rectifier/regulator in line,controlling the power received,consequently,there's much more tolerance if the original number of turns are missed.
 

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I've measured the resistance of:

Ignition Coil-
Primary-1.1-1.2 Ohms
Secondary- 16,810 Ohms

Magneto-

White/green wires(drives ign. coil)-835 Ohms
Brn/Red wires(drives CDI unit) - 0 Ohms
Brown wire to Earth- 0 Ohms


In measuring the output voltage of the Orange wire(to ign. coil)-0 volts


Also-
I believe that the following original,now unnecessary circuits should be left 'open'(not jumper-ed or grounded)

Neutral switch
Sidestand switch
Engine Run switch

-


hello lanser

here is what i have learned while going through a similar process with my 1990 bike (turns out to be a bad cdi, which i intend to sub with a 2010tw cdi, half the price; but that's another story).

anyway, as you say, the problem you are having seems to do with the source coil wiring which powers the cdi (perhaps one wire for low speed/one high, or one for power/one gives an increasing -with-rpm voltage to advance timing?).

if the bike was working prior to dissassembly you probably "just" pinched and shorted the wires to ground, it's a stupid case design, way too much contamination' and pinchin' action for my liking.


wires from stators

wh + green pulse/pickup coil. tells cdi when to fire. ~.6vac @low idle. pulses at tdc. also can test with an led.
this coil is not connected to "ground", connect to both wires. ~700ohm between.

red source coil pwrs cdi ~110vac to grnd @low idle ~400ohm to grnd
brn " " " ? ~3vac to grnd at low idle ~30ohm to grnd


cdi wires


above wires, and,

blk grnd
blk/w kill not grounded to run
blu/y interlocks must be grounded to run
blu this connects to the starter interlock relay, via the clutch lever switch. it does not effect ignition only e-start.
orange timed capacitive discharge output to spark coil primary.


i have put spade terminal disconnects on the kill and interlock wires, and also a couple spade jacks connected to a good ground, so a) i can hard patch to bypass interlocks for testing, and b) the spades are always a convenient place to ground one's meter, so to speak.

-
 

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Markings on my CDI



Wiring from CDI, note the two taped unused wires.


Hope this helps


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hi hellwig

that part number should be for the 1988-97 tw200. not sure about the extra yellow wire on yours.

here http://tw200forum.com/forum/technical-help/2509-tw200-cdi.html gives some tw cdi numbers and pricing. so that cdi you have is also the correct one for my bike, which would cost me $450+tx up here. the 2010 unit is $230 +tx here.

from what i understand, after hours on the forums and looking at the wiring diagrams, all the tw cdi ign systems are "electrically the same" but have physical changes (connectors, same stators but different placements on the different sidecovers, etc). the charging systems changed but not the ignitions. why the cdi's are priced so diffently i don't know. the engines didn't really change. confirmation by someone who actually did this swap would be great, the 2010 seems to be the cheapest.

i think we are stuck with using tw cdi's, short of also swapping out stators from other bikes to match the donor cdi, as some have done.

the tw bikes have no mechanical timing advance, so that has to be handled electrically by the cdi. then there is the question of when the cdi gets the base timing signal. the tw pickup pulses at tdc. other bikes can have base signals at 10-30 deg btc. this is an oft-overlooked but core compatability issue, then there is source coil/power compatablility. i have not found a cheap 12v-powered "universal" cdi that has built in timing advance.

i even hooked up a ford duraspark conversion (automotive 12v cdi ignition, relies on mechanical/vac for advance), using the stock tw pickup signal, but it sparks at tdc or a hair post tdc, so the bike just barely idles. tagging a mechanical advance settup for points or pickup coil onto the side of cam sprocket (extend the cam sprocket bolt out through the sidecover) wouldn't be that hard and one could use those universal $30 fixed-timing cdi units.

-
 

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Discussion Starter #20
Thanks once again,slowmod & hellwig,for your comments and help. I've simply set the TW off on the sidelines while continuing more searching. I'm going to try a CALRIC stator ass'y first,only because of their availability and low cost-that is,provided I get encouraging answers to some questions I'll ask. At $70 USD per unit(w/free shipping),I'll be the lab rat.....I am sceptical as to why they would select the TW as a model to fab/offer units for. I suspect the stator is used(with little or no changes) in other bikes worldwide that we're not aware of. I'll certainly continue to search for a used OEM stator as well.
Your specifications were very helpful,slowmod-thank you-it identified an error that I was making by not grounding the blu/yel wire. Unfortunately,my source coil does read '0' rather than 400 ohms....:(

I'll keep you all posted....
 
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