Paul G. Well I'm a bit bummed because I ordered up a used CDI for $50 this morning from Portland and I think it's on its way.
I'll mess with my connections a bit tomorrow and see if it solves my problems as well. If so, I guess I'll be selling my 'extra' CDI. Dennis G. - seattle -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of oldschoolgwin Sent: 03 June, 2009 21:06 To: Nighthawk Motorcycle Lovers! Subject: [Nighthawk Lovers] Re: Formerly 700SC Carbs - now ignition Dennis G. Please see my post under "83 NightHawk 650 no spark on center two cylinders " -in summarry the root cause appears to be corrosion of the connecters. Read the post - perhaps this is a solution that my resolve your issue as well - considering we have identical symtoms as far as i can tell. Hope this works, Paul G. On Jun 2, 9:37 pm, Dennis Hammerl <[email protected]> wrote: > Without any long, boring explanations.. think of a four cylinder Jap > bike as two twins. Independent everything, little shared. Kinda' like > losing one channel of a stereo amplifier. As for used parts, given the > cost of new (if available) I don't see much of a problem. Electronics > are go /no go items. Our shop has for a music system a 1971 Sony > receiver that runs 9 hours a day, six days a week. Works great. It > replaced a unit that failed after only a year from new back in 2000. > For the most part, bike electrics most often fail from dumb stuff that > could have been avoided IE; jump starts with incorrect polarity, bad > grounds allowing voltage surges, etc. > > --- On Tue, 6/2/09, oldschoolgwin <[email protected]> wrote: > > From: oldschoolgwin <[email protected]> > Subject: [Nighthawk Lovers] Re: Formerly 700SC Carbs - now ignition > To: "Nighthawk Motorcycle Lovers!" <[email protected]> > Date: Tuesday, June 2, 2009, 5:29 PM > > Dennis, > > I have the exact same issue on my newly aquired 83 650NH. Went > through the same diagnosis steps as you (confirmed by Dennis H - > thanks Dennis). > > What does seem wierd is the loss of half the output (i.e. 2 inner > cylinders loose spark) instead of loosing all output of the CDI. > > Does anyone have any experience as to how the CDI fails? Is it two > independant circuits in the CDI where we would expect only half of the > CDI output to fail? > > I am going to try and repair mine - because if i buy an old one ($50 > to $100) how long will it last? > > I wonder how often the CDI's fail on bikes this old? > > If i'm succesful on repair I plan to write a BKM for others to use. > > Paul > > On Jun 2, 6:46 am, "Dennis" <[email protected]> wrote: > > > > > The Honda manual refers to it as the "Spark Unit". It says on it, > > "Igniter". And I think they may also be called "CDI" and I'm > > guessing that this is an acronym for "Capacitive Discharge Igniter". > > When you take the tank off on a CB700SC, it is the square box > > mounted on top of the central frame bar near where the rear of the > > tank sits. > > > Dennis G. > > - Seattle > > > -----Original Message----- > > From: [email protected] > > > [mailto:[email protected]] On Behalf Of Graham > > Rogers > > Sent: 02 June, 2009 01:44 > > To: [email protected] > > Subject: [Nighthawk Lovers] Re: Formerly 700SC Carbs - now ignition > > > what's a spark unit? > > > On Jun 2, 2009, at 12:24 AM, Dennis wrote: > > > Dennis, > > > Thanks for your help! The bottom of 19-4 says I'll be needing a > > spark unit since all the other parts seem to check out. I'm > > guessing this part is no longer available from Honda and I'll need > > to get it from a yard that parting out a CB700SC? > > > A general question to any and all - anyone have one of these or seen > > one go by recently? > > > Cheers! > > > Dennis Gallagher > > - Seattle > > - one running CB700SC '85 and one half running CB700SC '86. > > > -----Original Message----- > > From: [email protected] > > [mailto:[email protected]] On Behalf Of Dennis > > Hammerl > > Sent: 01 June, 2009 20:28 > > To: [email protected] > > Subject: [Nighthawk Lovers] Re: Formerly 700SC Carbs - now ignition > > > Sorry.. your answer is at the bottom of page 19-4. > > > --- On Mon, 6/1/09, Dennis <[email protected]> wrote: > > > From: Dennis <[email protected]> > > Subject: [Nighthawk Lovers] Formerly 700SC Carbs - now ignition > > To: [email protected] > > Date: Monday, June 1, 2009, 10:03 PM > > > Dennis, > > > I pulled the cable that runs from the ignition block to the pulse > > generator and I measured the leads going to the pulse generator, as > > the manual described, and on the wht-yel pair (cyl 2,3), I got 349 > > ohms and on the wht-blu pair (cyl 1,4), I got 349 ohms. > > > They didn't say how to test the ignition block. > > > I'm going to put it all together again and see if it behaves the > > same. > > > I'm most interested in your thoughts on "where to next" in this > > troubleshooting. > > > Cheers! > > > Dennis Gallagher > > - Seattle > > > -----Original Message----- > > From: [email protected] > > [mailto:[email protected]] On Behalf Of Dennis > > Sent: 01 June, 2009 18:42 > > To: [email protected] > > Subject: [Nighthawk Lovers] Formerly 700SC Carbs - now ignition > > > Dennis, > > > OK. I pulled the coils out and the primaries measure 3.2 ohms and > > 3.2 ohms and the secondaries are 14.9K ohms on the left coil and > > 14.7Kohms on the right coil. I'm thinking that they are OK? > > > Back to the manual now to see what's next. > > > Dennis G. > > - Seattle > > > -----Original Message----- > > From: Dennis [mailto:[email protected]] > > Sent: 01 June, 2009 16:56 > > To: '[email protected]' > > Subject: Formerly 700SC Carbs - now ignition > > > Dennis, > > > I opened the screw on each of the four bowls and had gas in each. > > > Then I pulled the four spark plugs out and attached each to its plug > > wire and laid all of them on the metal fins and cranked the bike > > over. The two inner plugs, which correspond to the coil on the > > right had spark. The two outer plugs had no spark. I think the > > non-sparkers are both driven by the coil on the left as you face > > forward. > > > That's the news so far. > > > I'm going to see how hard it is to remove the coils so I can check > > all their connections and measure their primary and secondary > > resistances. But I am open to 'what's next suggestions". > > > Cheers, > > > Dennis Gallagher > > - Seattle- Hide quoted text - > > > - Show quoted text -- Hide quoted text - > > - Show quoted text - --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Nighthawk Motorcycle Lovers!" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/nighthawk_lovers?hl=en -~----------~----~----~----~------~----~------~--~---
