[Konkkaronkka]

Hello

I still have a cold start problem. It idles and runs perfectly when hot. The whole engine rebuilt. When hot it starts within 0.5 second with start motor or pedal. Cold start is difficult even if I use Quick Start Spray including ether directly to carb throttle. Started to think that I have a coil problem. The spark really looks blue and weak. I changed the coils (used) during rebuild as the old were mechanically damaged but still working). Before rebuild the cold start was OK.

Questions
Is the right resistance for primary about 3 Ohms?
What should be the secondary resistance?
Can you recommend aftermarket coils, seems to be several suppliers, both 3 and 5 ohms available, which to choose?Any other ideas.

The engine really runs nice when hot.

 

[J-T]

Are you using the choke when starting cold?

 

[Konkkaronkka]

Yes, thanks. I use choke, tried with different positions but this is something I called "Fatal Error". Should put it to oscilloscope and see secondary voltage but spark seems to be really weak. I understood that the coil bracket needs not to be earthed?? Or should it? The other end of the secondary is evidently connected to primary end.

 

[Konkkaronkka]

Yes, and even with Start Pilot it wont start when cold, really strange. The weak spark (or shortcut inside coil) is only thing which comes to my mind. I found the old coils, perhaps I try with them or buy those:
https://www.ebay.com/itm/HONDA-CB35...d=152821286523&_trksid=p2047675.c100005.m1851
or
https://www.ebay.com/itm/Ignition-C...ash=item2caf0a47e7:g:kgkAAOSw4HVWEFFN&vxp=mtr

Any experience of those?

 

[Konkkaronkka]

Just realized that the coil bracket must be well earthed as the condenser is earthed through the bracket. This can be my case. Well painted Honda frame after restoration...
Any opinions? Where are our "Ignition Specialists"?

 

[HerrDeacon]

I'm no where near an ignition specialist but thinking that could be your issue. I just repainted my CB350 frame and noted the exposed frame sections on both side under the coil bracket. I taped them off when painting but no where near ready to fire mine up.

You can see it here in this picture.

 

[Konkkaronkka]

Hello
Thanks for comment, yes, I believe this, too. Have to polish the frame from paint and see. Keep you informed.
Nice bike!