Topic: CB550 points keep going bad?

[nothin_ALL]

I didn't see a topic that helps me clear this up.  A couple of weeks ago my 74cb550 started bogging down the way it might when you need to switch on the reserve tank.  It did this a few times and then it would run fine.  Finally I had to crawl home on two cylinders.  I noticed the points were white and in bad condition, I set the gap and used a points file to get them smooth and clean.  I ran it for about 80 miles and the same thing happened.  The points looked white again, and I was getting intermittent or weak spark.  So I swapped them for new points and new condensers, it ran great for about 80 miles, and then the same thing happened.  Coils?  Thanks.

[carnivorous chicken]

Yes, using the wrong coils can lead to premature point wear. What coils are you running?

[Gene]

Also - what points did you replace the originals with?  The Daichi are allegedly notorious for going bad.

[flybox1]

Got a picture of your white points?
When was the last time you dropped bowls and pulled your jets for a cleaning?

[BomberMann650]

A daichi condenser can fail in a spectacularly short amount of time.
I havent experienced too much issue with the actual contact breaker.  5kmi on a breaker set.

[nothin_ALL]

I have the sock coils.

The points are Diachi, condensers too.  Only 80 miles on the new ones.  I looked for another brand but could not find a source.  And some sellers don't disclose the manufacturer on their website. I don't buy off ebay but if someone has a source I would be happy to try swapping these out.

I've cleaned the carbs about 6 times in the past twelve months.  That's my go to for all issues but they are clean, and the tank has recently been lined, and the carbs cleaned twice post lining.  When this issue first occurred I cleaned the carbs first and then narrowed it down to an ignition issue. 

[BomberMann650]

You can still get OEM condensers, they're out there.  $60 for the pair.

Or show hondaman some love and order his transistorized upgrade for $75

[alacrity]

You can still get OEM condensers, they're out there.  $60 for the pair.

Or show hondaman some love and order his transistorized upgrade for $75

YES>  But even with HONDaMan's Genius ignition box, you still have to have properly functioning points, and the daichi are crap because they bounce, where the OEM honda points TRACK over the cam lobe/hump.  The points act as microswitches to trigger the ignition box to tell the coils to GO MAKE FIRE.  IF the points are outta whack or bouncing and the dwell is hunting about, you will be confusing the magic box.  Mark (hondaman) walked me through a diagnostic process on this on a previous bike, and this is what we came up with as the prob. I put OEM points and condensers on the bike, set the timing again, and the thing started running perfectly before I could remove my thumb from the button.

[flybox1]

NEW TEC points are spendy.   Recycle!
For 1/3 new cost you can buy a used OEM points plates.  Sometimes multiple complete plates.
( Some even come with an advancer unit...a nice $50 bonus part.  Like this one: 
http://www.ebay.com/itm/70-74-HONDA-CB750-FOUR-OEM-IGNITION-POINTS-PLATE-PICKUP-BREAKER-PULSER-/112042554111?fits=Model%3ACB750&hash=item1a1641b2ff:g:xRYAAOSwuzRXdA2n&vxp=mtr  )
Disassemble.  Clean.  Treat the breaker surfaces.  Grease the cam felt.  Install.

[BomberMann650]

Wait flybox, the felt wiper is supposed to be greased?!

[DaveBarbier]

The felt is the "oil supply" to keep the points cam lubricated* and clean. If it's all dry, you'll wear out the points foot.

*Not too much or it'll be slinging oil around.

OP, this happens on only one set of points? The same points every time?

[nothin_ALL]

Happened on each point switch.

With the original points (original to me owning the bike) both had a white spot and were sparking enough to see in a well lit garage.  I cleaned them and then it would happen again after about 40-80 miles again.  I actually carried a point file so I could clean them when I rode.  New points and condensers installed, all was well for about 100 miles then the same thing. 

[grcamna2]

I bought 2) condensers from Autozone,Duralast brand made for a vintage Chevy Biscayne and these had a date code on the boxes,check that they're not more than 5 yrs. old as shelf life does cause the inner parts to break down.I installed them on my bike and they have been good ever since.When the condensers go bad they cause a Lot of sparking on your points and will burn them up right quick.

[nothin_ALL]

Yeah maybe the condensers are just bad.  I've read there is a way to test them by charging them and then discharging them, seems ripe for shocking yourself.  Where are people buying these?  Most sites don't claim who makes theirs.   

[grcamna2]

Yeah maybe the condensers are just bad.  I've read there is a way to test them by charging them and then discharging them, seems ripe for shocking yourself.  Where are people buying these?  Most sites don't claim who makes theirs.

The bike will run great w/ auto condensers that're good quality,just make sure they're fresh.

[DaveBarbier]

Yeah maybe the condensers are just bad.  I've read there is a way to test them by charging them and then discharging them, seems ripe for shocking yourself.  Where are people buying these?  Most sites don't claim who makes theirs.

I usually search eBay and eventually you'll find them. TEC or Nippon Denso are good brands. If you see a three leaved flower in the pictures, avoid it.

You can't trust that test for the condensers, my last failing condenser tested fine, but when I checked timing with a strobe it was erratic.

I find it hard to believe that even the garbage Daiichi condensers/points failed at the same time. Which is what I understood from your reply to my question. I honestly don't know much about electrical stuff, but is the points plate grounded well? It has three mounting screws, so I'd bet it's fine but just a thought. I'll leave this up to the pros.

[grcamna2]

Yeah maybe the condensers are just bad.  I've read there is a way to test them by charging them and then discharging them, seems ripe for shocking yourself.  Where are people buying these?  Most sites don't claim who makes theirs.

I usually search eBay and eventually you'll find them. TEC or Nippon Denso are good brands. If you see a three leaved flower in the pictures, avoid it.

You can't trust that test for the condensers, my last failing condenser tested fine, but when I checked timing with a strobe it was erratic.

I find it hard to believe that even the garbage Daiichi condensers/points failed at the same time. Which is what I understood from your reply to my question. I honestly don't know much about electrical stuff, but is the points plate grounded well? It has three mounting screws, so I'd bet it's fine but just a thought. I'll leave this up to the pros.

Speaking of grounding,it won't hurt to make sure the engine to frame is clean and making a solid metal to metal contact for ground,that will help your charging system also.

[nothin_ALL]

I'll check the ground.  I have some electrical demons, like sometimes my starter button works and sometimes it doesn't...

[grcamna2]

I'll check the ground.  I have some electrical demons, like sometimes my starter button works and sometimes it doesn't...

Sometimes when someone has the frame powder coated and they install the engine w/o cleaning off the frame areas that make contact w/ the engine it doesn't help.

[alacrity]

I'll check the ground.  I have some electrical demons, like sometimes my starter button works and sometimes it doesn't...

Yeah bro that certainly sounds like an intermittent ground problem...   You can't have too many ground wires. You can have too few. You can have some that aren't perfectly grounded, but you can't have too many.  PRIMARILY check the fat black one from batt to frame - it has to be touching pure clean raw steel on the frame and be TIGHT up against it.  At your ignition, run an extra ground wire from the main plate to the frame (either inside the ignition cover area to the engine, or BETTER  feed the wire out to another spot on the frame that you have etched to be bare metal at the attachment point.  at least then you will know if this was your problem.

[seanbarney41]

Bad condensor causes uour points yo go ba

Yeah maybe the condensers are just bad.  I've read there is a way to test them by charging them and then discharging them, seems ripe for shocking yourself.  Where are people buying these?  Most sites don't claim who makes theirs.

I usually search eBay and eventually you'll find them. TEC or Nippon Denso are good brands. If you see a three leaved flower in the pictures, avoid it.

You can't trust that test for the condensers, my last failing condenser tested fine, but when I checked timing with a strobe it was erratic.

I find it hard to believe that even the garbage Daiichi condensers/points failed at the same time. Which is what I understood from your reply to my question. I honestly don't know much about electrical stuff, but is the points plate grounded well? It has three mounting screws, so I'd bet it's fine but just a thought. I'll leave this up to the pros.

bad condensor causes your points yo go bad fast...thats what the condensor is there for, to keep your points from burning up from the high voltage needed to jump the spark plug gap.  Your engine will run with no condensor, but not for long.  Points can be filed, cleaned, and regapped, but if condensors are bad the points will quickly burn and pit.

[alacrity]

Bad condensor causes uour points yo go ba

Yeah maybe the condensers are just bad.  I've read there is a way to test them by charging them and then discharging them, seems ripe for shocking yourself.  Where are people buying these?  Most sites don't claim who makes theirs.

I concur. Condensers SEEM like simple items that never wear out... but that's not the case.  DAICHI condensers are so consistently crappy that I cannot understand how they stay in business.  Get some OEM honda ones... your problems will disappear (if this is indeed the source of your problems).


I usually search eBay and eventually you'll find them. TEC or Nippon Denso are good brands. If you see a three leaved flower in the pictures, avoid it.

You can't trust that test for the condensers, my last failing condenser tested fine, but when I checked timing with a strobe it was erratic.

I find it hard to believe that even the garbage Daiichi condensers/points failed at the same time. Which is what I understood from your reply to my question. I honestly don't know much about electrical stuff, but is the points plate grounded well? It has three mounting screws, so I'd bet it's fine but just a thought. I'll leave this up to the pros.

bad condensor causes your points yo go bad fast...thats what the condensor is there for, to keep your points from burning up from the high voltage needed to jump the spark plug gap.  Your engine will run with no condensor, but not for long.  Points can be filed, cleaned, and regapped, but if condensors are bad the points will quickly burn and pit.

[nothin_ALL]

Update,
I checked the ground wires and cleaned anything that looked questionable with sandpaper down to bare shiny metal. 

I put new condensers on and reset the points gap.  The bike runs now and has power, but the points are sparking intermittently.   I think the same thing will happen again.  Can bad coils cause the condensers to fail and points to arch? 

[grcamna2]

Do you still have the Daichi points in there ?

[nothin_ALL]

Yes.  Each one has developed a small white area.  The surfaces don't mate very well and where they do touch is where the white spot has developed.  seem like they suck