[Kurt B]

I have a 1978 CX500 with a charging issue. Last summer I was having issues with the bike cutting out under acceleration when it was hot out and replaced the CDI with an Ignitech unit and it solved the problem, bike ran better than ever. Last week I replaced the noisey, stock fan with the electric upgrade (Ducati fan, thermostatic switch wired to the battery with an in-line fuse) I took it out for a shake down run and everything worked great, fan turned on when it was supposed to and turned off when it was supposed to. I stopped for dinner and headed home and on the way home I noticed that the headlight was dim and as soon as I pulled into the garage it died. Tried to start it and it was dead. I charged it on a battery tender overnight and did some testing the next day. I tested the stator and everything was within range and checked out OK. I tested A/B, A/C, and B/C and all were 0. I also tested A/ground/5/neg battery terminal, B/ground/5/neg battery terminal, and C/ground/5/neg battery terminal and all were 0. I then checked the battery and got 13.22 when the bike was off, 12.30 with the headlight on and 12.33 at idle and 12.79 up to 4000 rpm. I assumed it was the R/R so I installed a new one from Rick's and got the same numbers after the install. I just rechecked the stator and now the 5/9 reading is 567, ran it through the online test and got "Some of the coils on your stator are faulty - if you are using the stock CDI you will need to replace the stator. The Ignitech does not require these coils to run." The battery is maybe 3 years old but is almost always on a battery tender when parked.

#1 - Since I have the igintech unit does this mean that I'm OK or do I need to replace the stator?

#2 - Is there anyone in the Chicagoland area who would be kind enough to take a look at it with me? I can pay you in beer.

#3 - Did the extra load of the electric fan cook something?

#4 - Is the battery OK?

Thanks,

Kurt

 

[nolimitz]

Have the battery load tested at an auto parts store. 3 yrs is pretty good for a lead acid batt.

 

[reclinedrelic]

You could measure the battery voltage while cranking the engine, kill switch in the off position. That would give you a better idea of the battery condition.

 

[Kurt B]

I had the battery tested at the auto parts store and it passed. The battery drops to 11.30 under load at start up which also seems good. I guess I was assuming that since the battery only shows 12.79 (nowhere near the 14 it should) up to 4000 rpm that the stator may not be charging. I'm getting the 12.79 figure with the old R/R and with the new R/R. Could it be anything other than the stator? I was hoping to not have to do the triple bypass if at all possible, but will do it if it fixes the problem.

Thanks,

Kurt

 

[Sidecar Bob]

I tested the stator and everything was within range and checked out OK. I tested A/B, A/C, and B/C and all were 0. I also tested A/ground/5/neg battery terminal, B/ground/5/neg battery terminal, and C/ground/5/neg battery terminal and all were 0.

Assuming those readings were measured with the stator unplugged from the regulator/rectifier and you did mean zero ohms (some meters read zero when they mean infinity), one or more of the stator's charging (alternator) windings is shorted to ground.

With a good meter you should read approx. 0.5 ohms between any combination of A,B & C and infinite ohms (no continuity at all - the same reading as when the test leads are not touching anything) between any of A, B or C and ground (the battery's negative should be connected to ground by a heavy cable so it is the same as ground).

 

[Kurt B]

Thanks for the reply Sidecar Bob. Yes, all measurements were with the stator unplugged and I did mean zero ohms (really it was about .1 - the same as when the leads are touching each other). The winding being shorted to ground makes sense now if all A, B & C to ground readings are zero and not infinity, thanks for the help, electrical stuff is not my strong suit. Since I have the ignitech CDI, should I go with a G47 or G8 Stator? Also, do you know if the 1978 CX500 model has the manual or automatic cam chain tensioner. I'm looking to buy all of the necessary parts before I start the triple bypass.

Thanks,

Kurt

 

[Sidecar Bob]

All CX/GL500 models originally sold in North America have the manual camchain tensioner. If it was me I would upgrade to the G8 stator. The G47's charging coils can only produce 170W, which is fine for running the lights and charging the battery (the other coils power the CDI) but when Honda replaced the CDI with the TI ignition they changed to the 250W stator similar to the G8 so that it would have power for the ignition as well as lights, charging and a bit to spare for accessories.

The first thing you should do is download the Factory Service Manual for your model (available through the CX Wiki - link in my signature) and, since your bike has had 40 years of Previous Owners who may or may not have done any of the work needed to keep it safe & reliable, start working your way through all of the maintenance procedures listed, whether your bike has reached that mileage or not.

I also recommend looking at all rubber parts with suspicion; Find the date codes on the tires and replace them if they are over 5 years old even if they look & feel good. Rubber brake lines on bikes should be replaced every 2-3 fluid changes (5-6 years) and yours is probably original; You aren't likely to find a new rubber line to fit but even if you could I would recommend upgrading to a stainless braided line (actually teflon tube with stainless wire braided over it) which will last forever unless physically damaged and should double the fluid replacement interval. Any time you have something apart replace every seal and o-ring you can get at, including the ones in the back wheel that keep the grease in the splines and the dirt out (dirt in the grease can grind the splines away in no time and then you will need a new spline flange and maybe a final drive) and especially don't forget to replace the one on the camchain tensioner bolt any time the engine's rear cover is off - you wouldn't want to drop the engine and take the cover off again if/when that ring starts to leak....

BTW: Welcome to the forum. Please add your bike's model and model year to your signature (see forum settings link in my signature) so that you don't have to remember to tell us every time and we don't have to keep asking when you forget.

 

[Kurt B]

Thanks for the info Sidecar Bob. The first thing I did when I got the bike was buy a used Honda Service Manual on ebay, worth it's weight in gold. I've already done quite a bit of work on the bike including: new tires, handlebars, cables, brake pads & shoes, ss brake line and exhaust. I've also rebuilt the carbs, master cylinder and caliper and the forks as well as the recent conversion to an electronic fan. I've found this forum to be invaluable and could not have done any of the work without it. So thanks again for helping me out.

Kurt

 

[Martinj]

Had a similar occurrence last summer with mine. In the process of replacing my stator. Due to circumstances it’s been a long drawn out process. I decided to upgrade to the G8 type. The info contained in the wiki on here on how to carry this out is first class , including coloured photos. Also gives a list of all the seals, o rings etc that will need replacing. Good luck with the project.

 

[Sidecar Bob]

Umm... Camchain adjustment is covered in chapter 3 of the FSM so you should have known that it has the manual camchain adjustment.
BTW: It is commonly recommended that you adjust the camchain when you are adjusting the valve clearances because you have to remove the covers from the port for viewing the timing marks on the flywheel and for turning the engine with a wrench for both.