Author Topic: Main Fuse Blowing (Read 2970 times)

tstruth · « **on:** May 29, 2016, 03:44:41 PM »

Hello all,

New to the forum. I purchased a 1981 Honda CB650 and discovered that it had a charging issue. Researched and decided to change the rotor. After doing so I replaced cover and discovered that the bike was dead. Found the main fuse and it was blown. There was an extra, I installed the new one and it blew as well. I checked the wires and do not see anything pinched or worn. I have been on the forum and other sites trying to find the solution but can't seem to find it.

Any help would be great.
Tom

tstruth · « **Reply #1 on:** June 01, 2016, 08:40:04 AM »

I ordered a new stator as well and when installing I noticed the brush base was cracked. I am hoping this is the cause of the ground issue and the blowing of the main fuse. I seem to have some trouble finding a new one. Every site states unavailable or discontinued. Does anyone know where I might be able to find one?

Thanks,
Tom

b52bombardier1 · « **Reply #2 on:** June 01, 2016, 10:14:44 AM »

I think I would have done more testing before buying a new rotor and stator. If you have a multimeter, there's a lot of things that could be tested before spending money perhaps needlessly.

Do you have the shop manual and a good multimeter? You almost can't get by without them working on bikes of this age. The shop manual is free and I'd spend 25 bucks on a good meter.

Rick

Sent from my SAMSUNG-SM-N900A using Tapatalk

Gene · « **Reply #3 on:** June 01, 2016, 05:23:48 PM »

Have you opened the rat's nest that is the headlight bucket yet? You have a short somewhere - could be a buncha things. Welcome to the forum - get your manual and a wiring diagram. Don't worry, it'll be fine.

tstruth · « **Reply #4 on:** June 04, 2016, 09:24:16 AM »

Thanks for the reply. I have tested the Rotor and I had no reading. Purchased new Rotor and I think the problem was with that. I have been trying to get the cover on and it does not fit perfectly. I must not of checked the fit and when I tightened up the cover bolts the first time as it cracked the brush base. That was hard to find seeing that parts are no longer be made. I put together the new brush base and slowly tried to install cover. It does not fit over the new Rotor. I pulled it and put the old one back on and the cover fit perfectly. I think I might have got a bad Rotor. I got the Rotor and Stator on ebay from Caltric. I will hope for a return. Any recommendations on a good place to buy parts.

calj737 · « **Reply #5 on:** June 04, 2016, 10:03:06 AM »

Send a PM to member, Bill Benton. I'm sure he has the proper parts for you.

tstruth · « **Reply #6 on:** June 25, 2016, 06:51:06 PM »

Received my new Rotor for my CB650 and it fit perfectly. Replaced the Brush Base and springs and things went back together nicely. Checked the R/R and it was bad, replaced that as well. Bike ran great for a couple of days and then died and would not start. Got a jump and pulled her back in the garage. Checked the battery and it was reading low. Took it down to the auto store to get it checked and it was bad. Purchased new one and in the morning after charging installed and she ran great for a week before I realized the rear light and instrument panel was not lighting up. Moved around the wires in the head light, they all looked good, and moved wires around else were and when I put the headlight back on the lights worked. Wow I thought I was doing good. Seems to be a short somewhere because the battery died on the next day when I was out. Put it back on the trickle charge and in the morning she was back up to full charge and has been running great for the last two days, I was about to take her out tonight and noticed the lights on the panel and back light were out again. Brake lights work, blinkers work, Puzzled.

Any suggestions?

b52bombardier1 · « **Reply #7 on:** June 25, 2016, 07:19:36 PM »

What do you see for DC and AC multimeter readings at the battery at idle and half throttle or so?

Rick

Gene · « **Reply #8 on:** June 26, 2016, 09:02:44 PM »

Disconnect the electric starter, see if the problem is resolved. Just curious.

tstruth · « **Reply #9 on:** June 27, 2016, 05:29:58 AM »

Battery is around 12.23 up and down. Over 200rpm she goes up to 13plus. The Rotor and the R/R are doing the job. I have to figure out how to set and read the meter to see were the connection could be loose or grounding. The Rat Nest looks pretty clean. There are a few empty connections with the plastic clear covers on them and they all look clean.

b52bombardier1 · « **Reply #10 on:** June 27, 2016, 05:50:58 AM »

You could place your multimeter inline between the battery post and the cable to check for a drain. We know you have one and now we need to find what is causing it - less so how much of a drain it is. Once the meter is inline and set to an amperage measurement, pull the fuses one at a time. This will tell you which circuit is your troublemaker.

I'm only going to mention this one time - DO NOT START YOUR BIKE WITH THE MULTIMETER SET UP IN THIS MANNER!!! You will either fry it, melt wires or blow it's internal fuse.

I'd still like to know what you are seeing for AC volts at the battery with the bike running.

Rick

Sent from my SAMSUNG-SM-N900A using Tapatalk

tstruth · « **Reply #11 on:** June 27, 2016, 05:55:58 PM »

I will try it tomorrow. Went for a ride with my sons and after 20 minutes the bike died. Why is it that the bike will die once the battery runs low? The bike starts to back fire a bit and then cuts out. I jumped it off my sons bike a few times to get it to his garage. Pulled the battery and checked it when I got home. It read 10.3. I have it on the trickle charger again. Could it be a bad battery? Getting a little nervous about taking it out again.

Gene · « **Reply #12 on:** June 28, 2016, 02:04:04 PM »

Quote from: tstruth on June 27, 2016, 05:55:58 PM

Why is it that the bike will die once the battery runs low? Could it be a bad battery?

Yes. The symptoms all point to no generation, however. Electricity is only being provided by the battery and when the battery is kaput, so is the bike. If the stator is not providing enough power to keep the bike running, let alone charge the battery . . . well, you see where this is going. Short answer - could be a bad battery, sure, but to me it sounds like something else in conjunction with what is probably a bad battery.

tstruth · « **Reply #13 on:** June 28, 2016, 03:32:40 PM »

Thanks, I ran the bike today and disconnected the R/R and nothing changed on the meter while it was running. I know the Rotor is good because it is new and it reads at the correct ohms.The Stator was not replaced. The new R/R i bought was bigger than the one I replaced. Hoping it's a bad R/R and this is the cause.

tstruth · « **Reply #14 on:** July 06, 2016, 11:43:25 AM »

Hello All,

Little update on my charging problem,
I installed the correct size R/R and went for a short 15 minute ride with a charged battery. Shut her down in the garage and went to restart and the battery was dead. I have read many stories from different folks with the same issue. I have tried many things and ordered parts from different shops in hopes that I could fix this problem on my own. I am throwing in the towel. I do appreciate your help and will let you know what the problem ends up being. I just want to ride this bike without needing a jump start to get her home.

scottly · « **Reply #15 on:** July 06, 2016, 05:16:13 PM »

Sounds like you still have a charging problem. Starting the bike with a fully charged battery, the voltage should climb to 14v+ with the motor revved up. If nothing changed when you unplugged the reg/rect, it confirms you're not charging the battery.

tstruth · « **Reply #16 on:** July 21, 2016, 10:07:10 AM »

Looks like the second Rotor I purchased this past month is no good as well. Seems like the trouble with this charging system is finding good parts. I'm hoping the bike shop that it still sits in comes across a good place to find them. Does anyone out there know of any good places to purchase these parts to the charging system?

Scott S · « **Reply #17 on:** July 21, 2016, 09:14:38 PM »

I'm moving this to the SOHC4 forum in hopes it gets more views and you can get some help.

scottly · « **Reply #18 on:** July 21, 2016, 10:09:00 PM »

How are you testing the rotor? Are you measuring the resistance at the slip-rings?

tstruth · « **Reply #19 on:** July 22, 2016, 03:16:38 PM »

Just picked up the bike.She seems to be charging now. The mechanic told me that the Rotor was bad. That was the third new Rotor in two weeks. He also changed the R/R. I just put in a new one of those also. He said he wasn't sure if that was bad or not but changed it out anyway. On the ride home from the shop it stalled out a few times. The idle was low. Looks like a black knurled knob on the bottom of the carbs, I gave it a 1/8 of a turn clockwise. It seems to idle at 1200. Crazy how you get one thing fixed and another seems to take it's place. It's just like my boat.

tstruth · « **Reply #20 on:** July 22, 2016, 05:59:20 PM »

Just got back from a nice long ride. It was great being back on the bike and not having to worry about breaking down. Thanks to all for the help and advice. Greatly appreciated.
Tom

tstruth · « **Reply #21 on:** August 04, 2016, 03:10:10 PM »

Back again. Has anyone experienced Rotors going bad after 2 weeks. I just home from being towed. Took the bike for a ride to the Cape and she shut down after 80 miles. The bike ran great for two weeks. Not sure what could be causing this. Any ideas?

calj737 · « **Reply #22 on:** August 04, 2016, 05:29:31 PM »

I doubt it ever was the rotor(s). You didn't indicate what happened on the ride, or provide any information. Nor did you ever answer some questions posed prior the mechanic replacing the last rotor.

tstruth · « **Reply #23 on:** August 05, 2016, 08:28:41 AM »

Here is the story,

I purchased the bike from Craigslist. The bike started fine when i went to see it and I rode it 50 miles home. The bike started and ran fine for a week. When I went to start it in the garage the battery was dead. The PO told me that the battery was brand new and by the looks of it I took his word for it. I put the battery on a trickle charger and the bike started. I took it around the town. I went to start it again and it was dead. I purchased a new battery and trickle charged it all night. Went for a couple of rides and when I tried to start it again it was dead again. I went on and did some research and discovered that these bikes are known for a tricky charging system. I removed the Rotor cover and checked the rings with the meter. It was reading around 1-2. Cleaned them and checked it again, same thing. From what I read, this meant the Rotor was bad. I went on Ebay and found a Rotor for the bike. The price was around 80 bucks. I removed the old one and installed the new. I went to start the bike and the main fuse blew. I didn't realize that the Rotor cover was not flush on the bottom. I took it apart and realized the new Rotor did not fit. I tried many time pulling it off and reinstalling. The cover just would not fit flush. I pulled it again and installed the old one and the cover fit perfectly. I ordered another Rotor, checked it with the meter it was 4.5. Installed the cover and it fit perfectly. Went to start the bike and the fuse blew again. I removed the Rotor cover and noticed the brush holder on the Stator was cracked. I'm guessing this happened when I installed the first Rotor. I found a brush base on Ebay. I removed the Stator and installed the brush base, brushes and Stator, and the new Rotor. The bike started and died after a few rides. I purchased a new R/R, trickle charged the battery and after a few rides the same thing happened again. I sent it to a shop and they replaced the Rotor again saying the readings were all over the place and that it was bad. They told me they checked the connections on the Stator and they were good. They replaced the R/R as well and checked for any grounding issues. All was good they told me. I picked up the bike and the idle was a little lower than when I dropped it off. I adjusted the idle screw when I got home and she ran great for two weeks of short rides around town. I took it for a longer ride yesterday and when I went to fill it up at the gas station she would not start. Nothing happened on the ride as far as mechanical or over heating. The bike shop is puzzled as well. I removed the cover to check this new Rotor, one of the two connections where the wire is connected is broken off. There is no reading with the meter.

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Author Topic: Main Fuse Blowing (Read 2970 times)