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My bike has two CDI boxes under the seat. I have had many parts bikes so I had known good ones to replace them with. I changed one at a time with no change in the problems. I was tinkering around with it today and found minor wiring issues which I have fixed. Two things I did find though that I feel may be the cause of my problems. The first was the fuse box: the headlight fuse holder was melted pretty bad along with the wire. The wire insulation was melted where the wire went really close to the other fuse holders. There could have been an intermittent short there. The other thing I found was inside the tach. The moron that had this bike before me did a lot of shady work which I thought I had found it all. For some reason he had removed the tach before and when he reassembled it, he shimmed between the gage and the case with steel washers. These tachs are normally electrically isolated from the frame ground with rubber washers , grommets and spacers. I have removed the shimming he installed and I will give it a whirl tomorrow. Its 50 degrees and rain today. Thanks for your detailed input. I'll keep you posted. Sean.

insaneV4Honda wrote:My bike has two CDI boxes under the seat. I have had many parts bikes so I had known good ones to replace them with. I changed one at a time with no change in the problems. I was tinkering around with it today and found minor wiring issues which I have fixed. Two things I did find though that I feel may be the cause of my problems. The first was the fuse box: the headlight fuse holder was melted pretty bad along with the wire. The wire insulation was melted where the wire went really close to the other fuse holders. There could have been an intermittent short there. The other thing I found was inside the tach. The moron that had this bike before me did a lot of shady work which I thought I had found it all. For some reason he had removed the tach before and when he reassembled it, he shimmed between the gage and the case with steel washers. These tachs are normally electrically isolated from the frame ground with rubber washers , grommets and spacers. I have removed the shimming he installed and I will give it a whirl tomorrow. Its 50 degrees and rain today. Thanks for your detailed input. I'll keep you posted. Sean.

If you got good spare CDI boxes, treat them like gold. Honda charges C$800 per unit and a good used one will set you back C$200.....over a quarter of my Sabre's repair bill was for the cost of replacing the fried out CDI box.

Sabres seem to be a bit harder on the CDI boxes than Magnas. I don't know why but it seems that way. I have had many friends with Sabres; both V45 and V65 and most of them had CDI box issues. As a matter of fact, 3 friends I can remember had issues with the box that controls cylinders 2 & 4. I have had 5 V45 and 1 V65 Magna and have never had to replace one. Maybe I am lucky!

Can anyone tell me what the symptoms would be in the silicone rectifier that is embedded in the wiring harness was bad? According to the wiring diagram, it ties in with the clutch switch and the gear change switch. I never realized that this was a rectifier and have never had any problems involving this item.

The problem I described in my first post could be tied to this but I am not sure. If that rectifier in the diagram was shorted, current could flow either direction. Any help is appreciated. Sean

A rectifier turns AC to DC... if it fried then nothing hooked up to it would work.

Sev wrote:A rectifier turns AC to DC... if it fried then nothing hooked up to it would work.

The wiring diagram shows one single diode (silicone rectifier) on one single wire between the clutch switch and the gear change switch. I agree that a rectifier turns AC to DC. Knowing these details, does that spark any additional ideas? Thanks for the help! Sean

Do you have an electronic copy of the wiring diagram?

Off the top of my head...

older bike, the safety cut outs are possibly run off AC. But all it takes is a single diode to make "dirty DC" so it's possible that your clutch safety cut out is run off the generator as opposed to through the battery. If the diode were to fail the bike

wouldn't start in gear
would die if put into gear
not have a start in gear safety cutout

That's the only thing that I can really think of.

Remember it could potentially short and create an "open" depending on what kind of clutch cutout you have it's possible that the bike thinks your clutch lever is always out.



The thing about your problem that bothers me is it sounds like inconsistant powersupply. Your turn signals will blink fast when the flasher relay doesn't sense enough resistance across the circuit. Your lights will be dim... This is further supported by the face that the problem occurs between idle and 4500 rpm. Above that it is possible that the alternator output is enough to take care of all the bikes electrical systems.


Is your alternator electromagnetic or solid state magnets? Weak magnets or poor electromagnets might the reason you're having this troubles (you've replaced basically everything else).

The other option is that your wiring is getting old... which is to say that you possibly have corroded or loose connections somewhere in the charging system, or the wiring itself is starting to give out - broken strands or a short to ground.

I could check for resistance and shorting to ground from the wires that lead from your rectifier to your battery, and the connections from the stator too the rectifier itself. It might be time for a new wiring harness - or to run auxiliary wires in place of the stock ones.


Finally, I would not continue to run the bike in this condition, I have seen stators fry themselves as a result of being overstrained trying to charge batteries with loose or poor connections.


Hope my long-winded totally backwards explanation/theorization helped?

Sev, thanks for the great detailed response. I'll try to address each of your inquiries and give you some updates. I'll apologize in advance for being long-winded too. Yes, I do have an electronic copy of the wiring diagram. Last night after I got home from work I tested the diode and found it to be fine.

Now for the charging system. When I got the bike, the connector for the stator and voltage regulator was melted pretty bad. The wiring showed signs of overheating although they still tested fine, I replaced them with known good parts. The permanent magnet was good too. Still having running issues that I blamed the electrical system for, I changed all of the other items I listed before. More recently I found the stop/tail light sensor had signs of overheating and the fuse block (headlight fuse) was melted and so was the wire. Ultimately, I replaced the battery. My theory is that it was weak and was severely loading down the charging system. Not to mention the guy I bought it from was using a screwdriver across the starter solenoid to start the bike. Once I saw this I told him not to do it anymore. Once I got the bike, I replaced this part too. You have a very good point though about the existing wiring. With all of the overheating that did happen, I need to look at the stuff in the bundles too. I plan to completely rewire the plug that connects to the starter solenoid. It looks OK but shows signs of overheating too. I don't want to take any chances.

Its funny that you mention the turn signal system. A friend and I went out after work to grab a beer and talk shop. We also talked about the turn signals.

This bike has some aftermarket signals on it. The color of the wires don't match and are tricky. On my bike, solid green wires are ground. The front signals have two hot wires and one ground. On the aftermarket signals, the three wires are white, green and black. I'll bet that he had the green wire hooked to ground (should be hooked to the hot side of the park light), the white hooked to the actual blinker wire and the black to the parking light (should be to ground). If the wires for the parking light are reversed, it could feed 12V into the ground system which could cause some of the electrical headaches I am experiencing. I am going to verify those wires tomorrow and know that it is wired correctly. Some would argue that this would not make any differences but I have had this exact problem before. I just didn't think about it until last night. This does make some sense to me because the problem goes away when I squeeze in the clutch. The clutch safety switch would be providing a good ground for the turn signals when it is squeezed in. The only catch is that the signals won't work correctly until the RPM's actualls fall off below 2K. I plan to take the parking light portion out of the circuit and see how the signals respond.



The other thing we discussed is the performance I described earlier (like I hit a rev limiter at higher RPM's). Rather than being an electrical problem, I think it is fuel. Today I opened up the airbox just to check it out. I mentioned before that the guy that owned this before was not a mechanic at all. Well, I was looking through the receipts he gave me and noticed that he bought a carb rebuild kit. That is why I decided to look in the airbox. What I found made me sick. The four rubber tubes that should have been in place guiding air into the carbs were just laying in the airbox: ALL FOUR OF THEM!. Obviously he did not know how to reassemble the airbox and carbs. Getting those tubes to stay in place is tricky but you just have to know what you are doing. Once I saw this, I realized that there was a damn good chance he did not get the rubber diaphrams in place properly. They are harder to get reassembled properly that the airbox. If those diaphrams are not in place and they are leaking, my needles won't be lifting up at all or only lifting up partially. Even if one is bad or leaking, that could cause the poor performance issues I am dealing with at higher RPM. That could also explain why I am getting 54 MPG with this bike. Anyway, I will run it up tomorrow and look to see if I am lifting the needles up when it is running. Even if I am, I still need to pull the carbs and make sure they (diaphrams) dont have any pin-holes in them causing a leak. On the 82's the jets are also different from front to back. The pilots are all the same but the mains differ a bit. Just to be safe, I want to eyeball them myself. After what I have seen so far with his handywork, anything is possible.

So to sum it up from my first post, I feel I am chasing 2 problems. I think you steered me down the right path with the turn signals for the electrical stuff. The carbs just have to wait until the snow starts to fall. I really appreciate all of the feedback as ask for any additional suggestions. Thanks! Sean.

What is the charging voltage across the battery terminals at idle, 3000rpm and 5000rpm?

Sev wrote:What is the charging voltage across the battery terminals at idle, 3000rpm and 5000rpm?

I'll check it out this weekend and post the results of the tests. Thanks. Sean