Topic: Ignition point arcing / 2/3 constantly grounded

[Lupo_00]

Alright guys here’s the update. Long story short, it’s the condenser. But tell me more about my low numbers

Battery voltage: 12.25v
Ohms reading key off: 8.7
Voltage reading key on kill switch on: 10.39v
No continuity between yellow and engine with blue wire removed. Not grounding.

Once you mentioned the condenser reduces arcing across points, that seemed to isolate the issue. I figured let’s swap them. The arcing moved with the condenser to 1/4. No more arcing on 2/3.

I installed new condensers, coils, and plugs summer last year when I bought this barn find that didn’t run. Got it to start and then took the bike apart (not the engine). The bike didn’t see the road until September this year, so those “new” condensers only saw idling and about 30mi with the old points before I learned about the 3000mi tune up and it’s importance... i bought the condensers from vintagecb750.com. Unsure what brand, but they say made in Japan. Pics attached for everything.

[Don R]

 Thanks for the report. We all learn something when we hear what the issue was. Did you find some good ones yet?

[RAFster122s]

HondaMan thinks that pretty much all the condensers out there, even ones made in Japan, tend to be very short lived with the Daiichi being the worst failing out of the box or within 1000 miles or less. Only the TEC brand condensers work well and last.  Glad you figured out your problem and thank you for sharing the solution.
David

[Kevin D]

Alright guys here’s the update. Long story short, it’s the condenser.

Excellent!

tell me more about my low numbers

Battery voltage: 12.25v
Ohms reading key off: 8.7
Voltage reading key on kill switch on: 10.39v
No continuity between yellow and engine with blue wire removed. Not grounding.

I'd say your battery is weak/undercharged.
Is the 10.39v at the points or the battery?
Does the 10.39v include headlight on?
Will the battery spin the starter motor?
What's the battery voltage when running?

[maxheadflow]

While condensers are really nothing more than a capacitor, why not buy one from an electronics supplier?  Here is on that looks like it should work.  Solder on side to some sheet metal and make a lead to the points.

https://www.digikey.com/product-detail/en/wima/MKS4G032203G00KSSD/1928-1719-ND/9370631

This one has a 125C/257F temp range.

[Deltarider]

Yeah, they're a lot cheaper and you could mount them close to the coils if that's more convenient.

[HondaMan]

Yeah, they're a lot cheaper and you could mount them close to the coils if that's more convenient.

While condensers are really nothing more than a capacitor, why not buy one from an electronics supplier?  Here is on that looks like it should work.  Solder on side to some sheet metal and make a lead to the points.

https://www.digikey.com/product-detail/en/wima/MKS4G032203G00KSSD/1928-1719-ND/9370631

This one has a 125C/257F temp range.

The only caveat to this approach is: like Delta says - the electronic caps are not made to take 200-degrre (plus!) temperatures on the points plate, which is why they are in metal containers. The TYPE of capacitor is very important: if you use electronic ones these are the specs you must watch for, plus you must mount them somewhere else (like at the coils):

Capacitance: 0.24uF
Voltage (often called WV, or Working Voltage): 400vDC (or higher).
Type: either wound (round) non-electrolytic, non-polarized type, or plate-type, like polyester laminate.
Series impedance (aka Resistance) if given: less than 0.01 ohm per volt
Upper frequency response: no less than 4kHz in operation.

These are available: they will need to have flexible wires soldered to their plain-wire leads so you can add crimp connectors (bullet type) to make them fit into the harness. My favorite ones are made by Panasonic...

[maxheadflow]

Yeah, they're a lot cheaper and you could mount them close to the coils if that's more convenient.

While condensers are really nothing more than a capacitor, why not buy one from an electronics supplier?  Here is on that looks like it should work.  Solder on side to some sheet metal and make a lead to the points.

https://www.digikey.com/product-detail/en/wima/MKS4G032203G00KSSD/1928-1719-ND/9370631

This one has a 125C/257F temp range.

The only caveat to this approach is: like Delta says - the electronic caps are not made to take 200-degrre (plus!) temperatures on the points plate, which is why they are in metal containers. The TYPE of capacitor is very important: if you use electronic ones these are the specs you must watch for, plus you must mount them somewhere else (like at the coils):

Capacitance: 0.24uF
Voltage (often called WV, or Working Voltage): 400vDC (or higher).
Type: either wound (round) non-electrolytic, non-polarized type, or plate-type, like polyester laminate.
Series impedance (aka Resistance) if given: less than 0.01 ohm per volt
Upper frequency response: no less than 4kHz in operation.

These are available: they will need to have flexible wires soldered to their plain-wire leads so you can add crimp connectors (bullet type) to make them fit into the harness. My favorite ones are made by Panasonic...

The ones you say seem good.. The ones I picked were 400VDC but more important 200V ac since the signal is AC (with DC bias). 257F on the temp. I haven't look deeply into the specs but it will need to take the coil current when the points break.

[Tracksnblades1]

The newer but still old silicone capacitors  operate in higher temps well. Military, Aviation, Automotive, logging have implemented them for some time. Tiny in size big in performance and offered in temperature ranges to 250c (482*f) for those more challenging applications....

[Lupo_00]

Alright guys here’s the update. Long story short, it’s the condenser.

Excellent!

tell me more about my low numbers

Battery voltage: 12.25v
Ohms reading key off: 8.7
Voltage reading key on kill switch on: 10.39v
No continuity between yellow and engine with blue wire removed. Not grounding.

I'd say your battery is weak/undercharged.
Is the 10.39v at the points or the battery?
Does the 10.39v include headlight on?
Will the battery spin the starter motor?
What's the battery voltage when running?

Battery is definitely weak which was my hunch.  Just wanted to make sure there werent other reasons you guys might have in mind.  I'm looking to replace it for the beginning of the next riding season since this season is pretty much over and I'm still troubleshooting mechanically.  Unless you guys think that's stupid and I should just get a new battery immediately.


Where do you buy your TEC condensors?  I'm having trouble finding any with a google search.


And thanks everyone for helping out.  This forum has been a HUGE resource for me and the community here is amazing.

[Kevin D]

Where do you buy your TEC condensors?

My new ones came from David Silver USA, $23 each

Another alternative that doesn't even need condensers is a HondaMan ignition:
http://sohc4shop.com/catalog/product_info.php?manufacturers_id=12&products_id=32&osCsid=1f720d0a1705b7e894cbc3dbdbb06e8e
Many here have it, and vouch for it. It might be on my Christmas list after my recent condenser troubles. $78 + shipping

[Lupo_00]

Alright so how much spark is too much spark on the points. Any spark at all?

[Deltarider]

see vid in: http://forums.sohc4.net/index.php/topic,174506.msg2030492.html#msg2030492

[PeWe]

Hondaman ignition module = no arcing points.
I have capacitors (0.22uF/600V) I plan to mount outside where point cables connect to Hondaman module ( or main harness)
A capacitor between yellow - ground wire attached to points plate. Another capacitor between blue and same ground wire. No heat issues. Hondanan module has a green ground wire to be connected to point plate.

Hondaman ign module runs fine without. I have noticed some occasional misfires around 7000-8500 rpm that condensers solve.