Author Topic: Still Running like a dog!!!  (Read 1112 times)

Offline Colonial-Clive (yindi)

  • Colonial_clive
  • SOHC Member
  • Posts: 228
    • View Profile
Re: Still Running like a dog!!!
« Reply #45 on: August 12, 2019, 03:52:58 PM »
I fitted Boyer to mine and it ran bad I took it to D&M engineering it turn out after hours of fault finding the box was faulty they put a Dave silver unit on all problems solved. Turns out that I wasn’t the first one with this issue with the Boyer system.

Offline Johnwebley

  • SOHC Master
  • Posts: 2258
    • View Profile
Re: Still Running like a dog!!!
« Reply #46 on: August 12, 2019, 06:27:27 PM »


  have you got the old coils<

  maybe they could be breaking down when they get hot


 or,can you use a multi meter to check resistance etc
lifelong motorcycle rider,and fan

Offline jon stead

  • 1973 CB 500 K2
  • SOHC Expert
  • Posts: 328
    • View Profile
Re: Still Running like a dog!!!
« Reply #47 on: August 13, 2019, 07:08:25 AM »
1973 CB 500 K2, 2015 Triumph Bonneville T100 Newchurch

Online paulbaker1954

  • SOHC Pro
  • Posts: 507
  • I'll just be 5 minutes dear!!
    • View Profile
Re: Still Running like a dog!!!
« Reply #48 on: August 13, 2019, 08:41:51 AM »
http://www.sohc.co.uk/index.php/topic,8209.30.html

See reply #41

Thanks but all is wired as per Boyer instructions. Complete Boyer kit including box, stator plate, rotor and micro coils going back today for testing.

See what they say and move on from there
If you think there's light at the end of the tunnel it's usually another train !!

2016 Yamaha MT09 Tracer
1971 Honda CB500 Four K0

Offline florence

  • SOHC Pro
  • Posts: 929
    • View Profile
Re: Still Running like a dog!!!
« Reply #49 on: August 13, 2019, 09:27:12 AM »
I encountered a similar problem on a friend's CB550 back in 1988.  In the end we binned the electronic ignition and went back to points.

Recently, I was on the verge of converting mine to Boyer, but I think this thread has put me off the idea  :)

Online paulbaker1954

  • SOHC Pro
  • Posts: 507
  • I'll just be 5 minutes dear!!
    • View Profile
Re: Still Running like a dog!!!
« Reply #50 on: August 13, 2019, 09:33:25 AM »
I encountered a similar problem on a friend's CB550 back in 1988.  In the end we binned the electronic ignition and went back to points.

Recently, I was on the verge of converting mine to Boyer, but I think this thread has put me off the idea  :)

Lets not jump the gun it may not be the Boyer set up but I am running out of options  >:( >:( >:(
If you think there's light at the end of the tunnel it's usually another train !!

2016 Yamaha MT09 Tracer
1971 Honda CB500 Four K0

Offline jon stead

  • 1973 CB 500 K2
  • SOHC Expert
  • Posts: 328
    • View Profile
Re: Still Running like a dog!!!
« Reply #51 on: August 13, 2019, 10:31:16 AM »
I encountered a similar problem on a friend's CB550 back in 1988.  In the end we binned the electronic ignition and went back to points.

Recently, I was on the verge of converting mine to Boyer, but I think this thread has put me off the idea  :)

I’m running Boyer with their micro coils, first class operation. Nice bit of kit. Would highly recommend it.
1973 CB 500 K2, 2015 Triumph Bonneville T100 Newchurch

Offline jon stead

  • 1973 CB 500 K2
  • SOHC Expert
  • Posts: 328
    • View Profile
Re: Still Running like a dog!!!
« Reply #52 on: August 13, 2019, 10:32:33 AM »
I encountered a similar problem on a friend's CB550 back in 1988.  In the end we binned the electronic ignition and went back to points.

Recently, I was on the verge of converting mine to Boyer, but I think this thread has put me off the idea  :)

I’m running Boyer with their micro coils, first class operation. Nice bit of kit. Would highly recommend it.

As you say, £17 to eliminate it or confirm it’s the culprit, will be worth it.
1973 CB 500 K2, 2015 Triumph Bonneville T100 Newchurch

Online paulbaker1954

  • SOHC Pro
  • Posts: 507
  • I'll just be 5 minutes dear!!
    • View Profile
Re: Still Running like a dog!!!
« Reply #53 on: August 21, 2019, 01:15:25 PM »
Ah well wouldn't you know it, Boyer stuff was on soak test for a day and all checked out fine, stator plate, coils and ign module so am still chasing this really frustrating problem down.

Here is what happens in a bit more detail.

Bike starts, runs fine and idles lovely but as things warm up the afterfire starts occuring. It is sporadic and not at all regular and occurs only on 1 and 2.

Here are my thoughts

1) I don't think this is carb related as idling etc is prefect until things warm up. I am going to hook up a manometer to the float drain to watch what happens to fuel level though.
2) I am running now with the Boyer stuff connected direct to battery and with a new 2 core cable from stator plate to Boyer. In other words nothing Boyer related is going through the loom
3) It seems Boyer box can suffer from RF and/or stray AC leaking in to the wiring so I have tested Rectifier Diodes and all good so doubt any AC leakage but I am going to check with an AC ammeter to double check.
4) I am also going to try running with the Boyer stuff powered from a completely separate spare battery
5) I have checked the plug caps (NGK) and 3 are at 5K Ohms and 1 at 4.3K Ohms (new cap ordered in case that 1 cap is the issue.
6) have bought a new Elextrec Rectifier/Reg unit but not fitted yet as the original Diodes check out OK, will fit if ther is AC leakage or no charge coming through from exisiting rectifier

I have to say this is THE MOST frustrating problem I have ever had  >:( >:( >:(

Have I missed anything obvious I should be dooing testing wise/checking to track this issue down finally
« Last Edit: August 21, 2019, 01:26:32 PM by paulbaker1954 »
If you think there's light at the end of the tunnel it's usually another train !!

2016 Yamaha MT09 Tracer
1971 Honda CB500 Four K0

Offline Rob62

  • SOHC Pro
  • Posts: 685
  • ZZR1100D9, CB750K4, RD250F, NSR250MC21, C90ZZ
    • View Profile
Re: Still Running like a dog!!!
« Reply #54 on: August 21, 2019, 01:24:32 PM »
have you checked the valves i.e. compression test and valve clearance..  sorry if you already have, I didn't read back through the whole thread. I had a misfire on a 550 many years ago which I initially thought to be ignition or carburation related... but after much frustration I ended up having the valves re-lapped which solved the misfire and totally transformed the motor..

Online paulbaker1954

  • SOHC Pro
  • Posts: 507
  • I'll just be 5 minutes dear!!
    • View Profile
Re: Still Running like a dog!!!
« Reply #55 on: August 21, 2019, 01:28:27 PM »
have you checked the valves i.e. compression test and valve clearance..  sorry if you already have, I didn't read back through the whole thread. I had a misfire on a 550 many years ago which I initially thought to be ignition or carburation related... but after much frustration I ended up having the valves re-lapped which solved the misfire and totally transformed the motor..

Compression good on all 4 cylinders, actually valves were all re-lapped in only 1K miles ago. Valve clearances all good and valve timing double checked.

One thing I haven't done is check compression again once warmed up which is probably a good idea
If you think there's light at the end of the tunnel it's usually another train !!

2016 Yamaha MT09 Tracer
1971 Honda CB500 Four K0

Offline K2-K6

  • SOHC Master
  • Posts: 2465
    • View Profile
Re: Still Running like a dog!!!
« Reply #56 on: August 21, 2019, 03:43:14 PM »
I can't remember if you said you had the barrels off this engine,  in other words have you seen all of the piston rings?

Frustrating as you say as you've verified most things.

Offer of std ignition to check setup by eliminating current system would be useful.

How have the carbs been synchronised?

Which number plugs are you using?

Online paulbaker1954

  • SOHC Pro
  • Posts: 507
  • I'll just be 5 minutes dear!!
    • View Profile
Re: Still Running like a dog!!!
« Reply #57 on: August 21, 2019, 04:37:32 PM »
Yes barrels been off very recently and rings all good in fact they are new pistons and rings only 2k mies ago.

Carbs synced with vacuum balancer

Will check plugs but was running fine on these plugs before

I should add this all started after a head gasket change and cleaning and adjusting of carbs
If you think there's light at the end of the tunnel it's usually another train !!

2016 Yamaha MT09 Tracer
1971 Honda CB500 Four K0

Offline K2-K6

  • SOHC Master
  • Posts: 2465
    • View Profile
Re: Still Running like a dog!!!
« Reply #58 on: August 21, 2019, 04:51:40 PM »
Try synching the carb's with Bryan method of mechanical setup and run it like that.  Don't put the guages on it at all.

Then setup the idle air screws as per Honda manual routine. It's very specific as to how it should be carried out for initial setup after carb rebuild.

Offline K2-K6

  • SOHC Master
  • Posts: 2465
    • View Profile
Re: Still Running like a dog!!!
« Reply #59 on: August 21, 2019, 04:57:21 PM »
Just an additional thought,  all the syncing blank screws are in place aren't they?  Non have fallen out?