TW200 Forum banner

1 - 15 of 15 Posts

·
Registered
Joined
·
32 Posts
Discussion Starter #1
Hi all!
After my battery did not charge I was searching for the problem(s). I found a faulty rectifier and replaced it. Still no charging and an equally dim headlight, when the engine was on. I had replaced that for a 55W lamp, which probably also was not the best thing to do.

So today I tested the Y-W cables from the charging coil. In the manual they say at 20°C the resistance should be between 0.3 - 0.5 ohm. I measured 1.3 - 5.5 (measured several times). Does that proof that the charging coild is faulty? I added photos how the charging coils looks like, I find the form very different from many others I saw on the internet for the TW 200. Is this due to the manufacturing year? Mine is 2000 and has run 30000km
How muc oil should I find in the cover? I emptied around 10ml.
Coils3.jpg Ignition.jpg Coils1.jpg
The arrow pointing to the ignition coil points to a hole in the plate. Shouldn't there be something stick out made of metal?? When the engine is warm, the ignition seems a bit "untimed". However, the bike is running otherwise ok.
Thank you for all your help and inputs!
 

·
Registered
Joined
·
32 Posts
Discussion Starter #3
Wiring

Did you replace the bad battery first and then check to see everything's charging?

Not sure about the hole you mention. I'd be more concerned about the burnt looking winding with the wires loose.
I saw that one, too, but it looks more like a thread to insulate (protect) the underlying wiring.
 

·
Registered
Joined
·
32 Posts
Discussion Starter #5
Hi again. I did not check the battery, being sure this was the problem. After the new also did not charge, I checked on the rectifer and found not a single contact intact, so I replaced it. Still the battery only run empty after charging at home, and that was it. In addition: With the blown rectifier I still had light. The intensity changed with the rpm. After I installed the new rectifier, the light was dim and stays large and wide dim. Going to see an electrician tomorrow. Will keep you posted. Thanks!
 

·
Registered
Joined
·
1,077 Posts
1. When you diagnosed did not charge, what was battery voltage with engine running at fast idle?

2. When testing the charging coil, what was resistance to ground/earth?

3. When testing the charging coil, where were ohmmeter probes placed?

Too low a read would indate some of the coil windings are internally shorted

If the read is infinity, the coil is open.

As you reported, with a high and an erratic read, there is too much resistance to connections.
 

·
Registered
Joined
·
1,861 Posts
I'm going through the same type of issue with another bike. I did change the rectifier/voltage reg. but did not change the stator. Besides checking for obvious or not-obvious shorts and kinks both the rectifier and stator will be changed out later on today. Good luck with your little project.
 

·
Registered
Joined
·
32 Posts
Discussion Starter #9
Thanks all for your help! @Sportster Doc: I will repeat the measuring and tell you, as it is still not working. I travelled, will be back Wednesday. I remember question number 3: White - Yellow cables showed 1.2 - 5 Ohm resistance, Did not try to ground. When I only inserted one probe on white or yellow cable, it showed 40 Amp and above? using both resulted in 20 Amp. How is this possible? Faulty instrument may be?

Btw., when fixing the rectifier to the frame/ground, it sparks. Is that normal??? To me the charging coils also looks kind of burnt/black. I just got an offer from Yamaha: 270 USD for a new charging coil. That's insane for a crappy part like this! I intend to find some meters of the right wire and wind them around like they were.... just trying.
 

·
Registered
Joined
·
1,077 Posts
Typically the rectifer is energized with key off, drawing about 1 milliamp, so, spark when ground completed not surprising.
Best to disconnect battery + or - before working on it.

You can wind a new coil
1. Using a micrometer, measure wire diameter, to purchase correct size of varnished wire.
2. Unwind coil, counting turns, then measure length.
3. Chuck laminates into lathe or = and wind slowly, in layers, while keeping tension on wire.
4. Dip in varnish, drip, bake in oven or mix 2 part non-conductive epoxy and pour over windings, keeping contact surface of laminate from build-op.

Without varnish or epoxy, windings will vibrate and short circuit.

Learned a few things in a motor rewind shop 1979-1983

Did not understand your 40 and 20 amp comments in post 9
 

·
Registered
Joined
·
32 Posts
Discussion Starter #11
Testing results

1. When you diagnosed did not charge, what was battery voltage with engine running at fast idle?

2. When testing the charging coil, what was resistance to ground/earth?

3. When testing the charging coil, where were ohmmeter probes placed?

Too low a read would indate some of the coil windings are internally shorted

If the read is infinity, the coil is open.

As you reported, with a high and an erratic read, there is too much resistance to connections.
Good morning SportstersDoc. Today I installed my old rectifier and now I have a normal, rpm dependend head light. I therefore assume that the new rectifier, not an oem, does not work on this model.

I did different tests:

1. Battery voltage is 7 V on idle and 9 V on high rpm (could be 5000)
2. Resistance charging coil to ground is 0.9 Ohm
3. Ohmmeter probes were placed on the contacts of white and yellow cable, unplugged.

In addition: White - black has 0.5 Ohm, Yellow - black 0.9.
With engine running idle, on white - yellow I get 9 Volt, high rpm gives up to 30 V

Hope you can make sense out of this?!

Thanks again for your help, much appreciated.
 

·
Registered
Joined
·
1,077 Posts
A 12 volt battery (12.6 lead acid, 12.8 AGM) should charge at 13.8 - 14.8 volts DC.

Was the white-yellow unrectified voltage on AC scale?
 

·
Registered
Joined
·
32 Posts
Discussion Starter #13 (Edited)
Charging Coil

A 12 volt battery (12.6 lead acid, 12.8 AGM) should charge at 13.8 - 14.8 volts DC.

Was the white-yellow unrectified voltage on AC scale?
Yes, correct. And I found out that despite the year of manufacture (2000) the system is an old one as you find it in models of 1987 with a old one phase coil. This includes that I have AC on the headlamp!
 

·
Super Moderator
Joined
·
4,851 Posts
Thought it might be, but you said it was a 2000 – that explains the headlight

Now all you need to do is find out if it’s just the stator from an ’87 (which would imply the entire engine), or the entire wiring loom, and then figure out what reg/rec you need on there

My understanding of the ’87 (I have a perfectly natural aversion to the things), is that the AC is to the headlight only, with the rest of the bike running on DC. If you try to match the component parts (wiring loom, reg/rec etc), it should be fine in principle. But if one of those components is “mis matched”, then it all gets as mad as a box of frogs

If you have an ’87 stator, then either you have an ’87 left crankcase (outer), or a whole ’87 motor. It’s not the motor you need to be concerned about, just the stator and everything above it

You have some reading to do …..

https://www.tw200forum.com/forum/technical-write-ups/19851-downloadable-tw-owners-manuals.html
https://www.tw200forum.com/forum/technical-write-ups/9958-colored-wiring-diagram.html
 

·
Registered
Joined
·
1,077 Posts
Yes, correct. And I found out that despite the year of manufacture (2000) the system is an old one as you find it in models of 1987 with a old one phase coil. This includes that I have AC on the headlamp!
So, you may need an 87 regulator?

Good info from Purple, but you may need input from 1987 owners.
 
1 - 15 of 15 Posts
Top