1981 cb750 charging problems1981 cb750 charging problems

I use these almost everyday Im on the job. Instructions not included. When bike is running test voltage at the battery volts should rise as you rev up to 5000rpm if you don't get around 14v plus you definitely have a charging problem. I had to do two roll-starts just to get it home. *Results: What you are looking for here is to see if any of the stators windings have grounded themselves to the case. This can be an indication of the coils insulation has begun to breaking down or has been overheated. Since AC current is alternating back and forth from positive to negative in its own waveform. Shows Voltage of your alternator rising and falling with RPM and gives a clear indication of your charging systems normal operation and early warning of problems. I had a similar problem with my 750. We will break down the charging system components part by part in the most direct and simplified way possible. The Fora platform includes forum software by XenForo. For a better experience, please enable JavaScript in your browser before proceeding. Dimensions 80mm Length, 94mm Width, 27mm Height, Hole Distance 70.0mm Center to Center. If your battery is charging perfectly but your motorcycle still seems to keep killing the battery. I'm having the same problem.. Thisrocks. *Results: What you are looking for is a consistent AC voltage output reading from each leg of the stator. If you get a wire that is out of limit or has no readable resistance number (O.L). 1. Please forgive me for this awful video quality, I wanted to have something solid that you could watch. It is over charging and buring out all bulbs. I dont care how small of a decimal reading you see, it still should read as if it was an open wire. #'s 31201-292-158 / 31201-MG9-004, Starter Motor Terminal (Cover) Rubber Boot. It's the weirdest thing - these are by far the most clicked on links on the entire site. possibly a bad volage regulator? Thanks Janie Answered in 8 minutes by: Motorcycle Mechanic: .. Brian : Good day and welcome to Just Answer. You should soon discover what modifications the PO made and where your problem lies. Check both over. Plenty videos on u tube. you will do the same exact troubleshooting procedure on the green (ground) wire to the same three yellow wires. Hello, my name is Edgar, How are you all doing? Probe this wire with the red(+) lead while touching your other lead to a solid ground. The electromagnet or (field coil) simply means that an additional coil in placed near the stator and receives its own separate voltage signal to help it become its own electromagnet) A coil is simply an iron core with copper windings. [] the key on giving you battery voltage? Honda CB750A Hondamatic. Ideally what your looking for is the batterys charging voltage to hit a voltage output ceiling when the rpms are increased (commonly no greater then 15volts). The rectifier is bad and will need to be replaced. OK, the yellows are not grounded out which I assume is good. So i still don't know if the lack of green, ground, in my wires plug going to the rectifier / regulator unit, would prevent the alternator from delivering voltage. 4. BIKE WON'T HOLD 13/14 VOLTS. CB750 New member. We use cookies to give you the best possible experience on our website. Honda CB750A Hondamatic. *Results: Since this wire needs a external signal. Cycle Forums: Motorcycle and Sportbikes Forum. Almost all reg/recs now-a-days are combined into one sealed unit. Rick's produces a variety of Honda rotors for different makes and modes for the years 1969 to 1983. stop losing sleep!just check those resistances. Let me explain. The "proper" way to test a charging system is to use a two meter test. (21 pages) Motorcycle Honda CB750F2 Owner's Manual. This post helped a lot of people out maybe have a look? Cold starting issue with 81' CB750. Do this with all three of the yellow wires. , Pre 1980, some bikes used these two systems as separated units. Bear in mind, this is theoretical knowledge being applied. The Rectifier is no good, and cannot be fixed. CB750c 1981 weak charge issue. Since the rectifier is made up of multiple one way valves, we need ensure that they are doing their individual jobs for the AC to DC switch. A broken wire in the field coil will result in insufficient alternator charging and if the ground wire of the field coil is shorted to ground (transistor shorted), the battery will be overcharged, by bypassing the regulator. Place one lead on the wire and the other lead to a solid ground. Rectifier Only - 3 phase - 5 Wire - 3 AC in - 2 DC out. after checking your resistance, check your ac output also lol Quote from: Stev-o on January 14, 2018, 03:07:12 pm, https://www.youtube.com/watch?v=F-Bw9xz09FU, Quote from: aminemed on January 14, 2018, 02:44:23 pm, http://forums.sohc4.net/index.php?topic=126401.0, http://forums.sohc4.net/index.php?topic=132935.0, https://www.cmsnl.com/classic-honda-fansite/honda_wiring_diagrams/CB750(K3-K7).jpg. He will fix you right up. Logo merchandise is available at the SOHC/4 Shop. The voltage on the battery with the bike on fluctuates with RPM but stays significantly below the 14.5 I expect to see. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register. I'm running out of ideas. Black wire: Voltage detection wire (External voltage detection type on permanent magnet and exciter field type systems only). I know its an old post just had to say thank you. VerticalScope Inc., 111 Peter Street, Suite 600, Toronto, Ontario, M5V 2H1, Canada. OEM # 31700-333-008 / 31700-323-015. Too much charge can cause overheating, meltdowns, explosions, and fires. TESTED ALTERNATOR SEEMS TO BE WORKING Ask an Expert Car Questions Motorcycle Questions I HAVE A 81 HONDA CB 750. Another thing that is a problem area is the cam chain . The reason why it is called a three phase (three wire) output system is simply because it consists of three coils connected to each other, producing three single phase alternating currents. The stator is going to probably take a week to get here. If not, check for breaks in the harness, or loose connections. Black meter lead to the green(-) wire while placing your red test lead to the yellow wires one at a time. It had starting issues at the time. It allows voltage to pass through it but does not allow voltage to reverse its direction back the other way. Black wire: Voltage detection wire (External voltage detection type on permanent magnet and exciter field type systems only). I have measured voltage at battery POS and NEG. Alternator Rotor Puller - 20mm x M1.5 Right Hand Thread Puller for pulling internal thread rotors. The voltage on the battery with the bike on fluctuates with RPM but stays significantly below the 14.5 I expect to see. New Bike Owner with charging problem. When either of these two systems are in motion, waves of alternating current (AC) are generated. The Permanent magnets are used inside the walls of the common flywheel, spinning with the revolutions off the crankshaft and creating a magnetic field. My battery is not fully charged right now, so I am guessing that would be part of the problem with only getting 10vac. This more than likely means that there is a break in the windings. It fluctuates 12-12.5V v depending on the battery charge and the rpm. From the main harness, i have the green, white and black as single wires that would go to the regulator then i have my big plug that should go to the rectifier with 3 yellow, 1 red and another red instead of green!! For a better experience, please enable JavaScript in your browser before proceeding. Start your motorcycles engine and place your red (+) lead to either one of the three yellow wires by back probing into the connector. Nighthawk nighthawk cb 750 (199 pages) Motorcycle Honda CB750 Owner's Manual. Changed voltage regulator - did not help. LED Charging system indicator Gauge. A low or failing battery can cause crazy readings during your testing. The stator needs to be replaced. You repeat this three times two check all three wires. The whole unit must be replaced as one. That means, that I have to charge the battery fully to use it again. JavaScript is disabled. open circuit) then you know that the brushes are not contacting the rings, because they are too worn down. what kind of accesories (like hotter coils) are you running? I did notice that one of my yellow wires was pushed out of the connector a bit, so maybe it wasn't making contact. I believe that bike is one of the early line of DOHC fours. Add to Cart. 22v at idle up . Here is a link to a CB 750 forum that covers the DOHC CB 750s. Any gurus around right now? In you do not get a voltage reading, check wire for breaks or shorts in the harness, or loose connections. Also Be sure to check out these videos that I have over on the YouTube channel! Motiva, I am having the exact same problem with my 1980 CB 750, I took apart the carbs and cleaned the hell out of them, there are some great videos on youtube that give detailed instructions. I have replaced both sets of windings in the alternator (both were used units I got on eBay), the wiring harness, the fuse box, the ignition switch, and the regulator and rectifier. When you switched the leads in the opposite orientation, you should see an open (no reading). It's a PITA trying to deal with this system. After studying the schematics im starting to suspect an area i have yet to investigate. Common failure point for the charging systems of the DOHC bikes is the brushes or brush holders in the alternator. CB750 charging problem HELP!! At 4K RPM it gets about 14.4 volts. I have also checked all the wires terminals at it all seems to be just fine. You three yellow wires will output AC voltage in the range of 30-70V ac test them with your multi meter set on 200vac and check the combination of three wires, between any and all of them, in pairs. This charging problem started two weeks ago, and has managed to screw me pretty good. I started having issues with it last year and since then I have replaced the voltage rectifier, the rotor, the stator generator, the carbon brushes and The battery. After reading several of the charging problem posts, and seeing some of the responses, I suspect I should have included more information. I HAVE A 81 HONDA CB 750. The demons are repulsed when a man does good. Good luck, old wiring sure is a treat. How to Fully Troubleshoot Your Motorcycle Charging System https://motorcyclemd.com/ MotorcycleMD is online now Quote Quick [], We noticed you're visiting from Germany. Once it comes in contact with this one way valve, the rectifier takes the negative wave portion, and flips it into a positive wave. You can do this test by first setting your multimeter to read AC voltage. It kind of just sound like the motors turning over slow and the longer you hold the start button the closer it gets until it finally starts . I have a 1981 Honda NX50M with a charging problem. October 14, 2022, 04:29:16 AM. If, say, the resistance between the two rings is 4.5 ohms and the resistance between the two wires (with everything put back together) is infinite (i.e. I have an 82 750sc and it is driving me nuts. Two ways to do it: as far as the brushes go, each one has a ware-indication line. Read full answer. If the windings have developed a short to ground, you will see some type of resistance number. Come join the discussion about performance, engine builds, classifieds, modifications, troubleshooting, maintenance, and more! Dismiss. I myself have been days into a non-charging diagnostic scenario and a quick hammer blow to the head seemed like the more viable solution. But, see with the meter where it does go. http://www.cb750c.com/publicdocs/CB750_Manual/Honda1979thru83CB750ServiceManualChapter01GeneralInformation.pdf, http://www.cb750c.com/publicdocs/CB750_Manual/Honda1979thru83CB750ServiceManualChapter02Lubrication.pdf, http://www.cb750c.com/publicdocs/CB750_Manual/Honda1979thru83CB750ServiceManualChapter03InspectionandAdjustment.pdf, http://www.cb750c.com/publicdocs/CB750_Manual/Honda1979thru83CB750ServiceManualChapter04FuelSystem.pdf, http://www.cb750c.com/publicdocs/CB750_Manual/Honda1979thru83CB750ServiceManualChapter05EngineRemovalandInstallation.pdf, http://www.cb750c.com/publicdocs/CB750_Manual/Honda1979thru83CB750ServiceManualChapter06CylinderHeadValve.pdf, http://www.cb750c.com/publicdocs/CB750_Manual/Honda1979thru83CB750ServiceManualChapter07CylinderPiston.pdf, http://www.cb750c.com/publicdocs/CB750_Manual/Honda1979thru83CB750ServiceManualChapter08Clutch.pdf, http://www.cb750c.com/publicdocs/CB750_Manual/Honda1979thru83CB750ServiceManualChapter09GearshiftLinkage.pdf, http://www.cb750c.com/publicdocs/CB750_Manual/Honda1979thru83CB750ServiceManualChapter10Crankcase.pdf, http://www.cb750c.com/publicdocs/CB750_Manual/Honda1979thru83CB750ServiceManualChapter11Transmission.pdf, http://www.cb750c.com/publicdocs/CB750_Manual/Honda1979thru83CB750ServiceManualChapter12CrankshaftPrimaryShaft.pdf, http://www.cb750c.com/publicdocs/CB750_Manual/Honda1979thru83CB750ServiceManualChapter13FrontWheelSuspension.pdf, http://www.cb750c.com/publicdocs/CB750_Manual/Honda1979thru83CB750ServiceManualChapter14RearWheelSuspension.pdf, http://www.cb750c.com/publicdocs/CB750_Manual/Honda1979thru83CB750ServiceManualChapter15HydraulicBrake.pdf, http://www.cb750c.com/publicdocs/CB750_Manual/Honda1979thru83CB750ServiceManualChapter16BatteryChargingSystem.pdf, http://www.cb750c.com/publicdocs/CB750_Manual/Honda1979thru83CB750ServiceManualChapter17IgnitionSystem.pdf, http://www.cb750c.com/publicdocs/CB750_Manual/Honda1979thru83CB750ServiceManualChapter18ElectricStarter.pdf, http://www.cb750c.com/publicdocs/CB750_Manual/Honda1979thru83CB750ServiceManualChapter19Switches.pdf, http://www.cb750c.com/publicdocs/CB750_Manual/Honda1979thru83CB750ServiceManualChapter20TechnicalFeatures.pdf, http://www.cb750c.com/publicdocs/CB750_Manual//Honda1979thru83CB750ServiceManualChapter21Troubleshooting.pdf, http://www.cb750c.com/publicdocs/CB750_Manual/Honda1979thru83CB750ServiceManualChapter221979CB750KFAddendum.pdf, http://www.cb750c.com/publicdocs/CB750_Manual/Honda1979thru83CB750ServiceManualChapter231980CB750KFAddendum.pdf, http://www.cb750c.com/publicdocs/CB750_Manual/Honda1979thru83CB750ServiceManualChapter241980CB750CAddendum.pdf, http://www.cb750c.com/publicdocs/CB750_Manual/Honda1979thru83CB750ServiceManualChapter251981Addendum.pdf, http://www.cb750c.com/publicdocs/CB750_Manual/Honda1979thru83CB750ServiceManualChapter261982Addendum.pdf, http://www.cb750c.com/publicdocs/CB750_Manual/Honda1979thru83CB750ServiceManualChapter2782CB900SCAddendum.pdf, http://www.cb750c.com/publicdocs/CB750K_wir_diag/Wiring_Diagram_CB750K_79___.pdf, http://www.cb750c.com/publicdocs/CB750K_wir_diag/Wiring_Diagram_CB750K_79LTD.pdf, http://www.cb750c.com/publicdocs/CB750K_wir_diag/Wiring_Diagram_CB750K_80___.pdf, http://www.cb750c.com/publicdocs/CB750K_wir_diag/Wiring_Diagram_CB750K_81_82.pdf, http://www.cb750c.com/publicdocs/CB750K_wir_diag/Wiring_Diagram_CB750C_80___.pdf, http://www.cb750c.com/publicdocs/CB750K_wir_diag/Wiring_Diagram_CB750C_81_82.pdf, http://www.cb750c.com/publicdocs/CB750K_wir_diag/Wiring_Diagram_CB750F_79_80.pdf, http://www.cb750c.com/publicdocs/CB750K_wir_diag/Wiring_Diagram_CB750F_81_82.pdf, http://www.cb750c.com/publicdocs/CB750K_wir_diag/Wiring_Diagram_CB750SC_82__.pdf. Thanks. Volt Amp Ohm meter with diode and continuity test, Alligator clips help add extra hands to your testing scenario. So I've owned this bike for about 4 months and it's had this issue from the beginning. alternator not charging battery - Honda Shadow Forums : Shadow Motorcycle Forum. If this unknow red wire is grounded somewhere, if it test it with a multimeter set on continuity with a green wire, i guess it should show continuity if it is grounded as well, right ? Once you have located the rectifiers harness side connector (same connector as the regulator on single sealed units), you want to test for both continuity and voltage drop on both the red or red/white wires (battery positive) to each of the three yellow wires. Once the wire snaps, no more charging at all nothing. They are broke down in chapters for easier downloading. Its in near mint condition, only has about 27k miles on it. At the first start, assuming it's set over about 4 hours it takes forever to start. Dan. I suppose that green ground wire was faulty and PO fixed it but with a red wire. Most common stator and flywheel combination . Now I'm stuck. resistance or continuity through the stators windings. Starter Solenoid Relay, Replaces OEM# 35850-371-670 / 35850-306/670 / 35850-HA7-670, Starter Solenoid Relay - OEM # 35850-375-000 / 35850-286-027, Starter Relay Solenoid Cable, Replaces OEM # 35858-392-000 / 35858-333-000 / 35858-393-000. Login with username, password and session length. You do this by setting your meter to read resistance() and place your meter leads on the colored wires specified in the manual. So I bought a 1981 CB750 about a year ago. . Welcome to SOHC/4 Forum Archives. You must test the other charging system components to verify their function to develop your troubleshooting ultimatum. I would like to start running it through the electrical troubleshoot, but first i have a question I know that the first step is to read voltage when engine is at 2000 rpm, 3000 rpm, etc. 2. Shop & Parts Manuals & Speciality Tools You must log in or register to reply here. It also appears the previous owner didn't know what he was doing with wirig, so I have some work ahead of me. Submit. Use that. Your right about the holder. We show up on loads of google searches now. could be that, theoretically. Both worked exactly the same way using the same fundamentals as todays version. The rest is left to run the ignition system and charge the battery. Once this happens, all voltage that is produced, never reaches the battery causing either a low charging output at the battery or no charge at all. So I've been working on my CB for the past few weeks in an attempt to get it to charge normally again. Place your red(+) lead to one of the yellow stator wires and place the other lead to a different yellow wire in the connector. Test this wire by setting your meter to DC voltage reading. Set your multimeter to read resistance(). (318 pages) Motorcycle Honda CB750F2 Owner's Manual. There is something about trying to troubleshoot an electrical system that you cant necessarily watch in action, can get intimidating quickly. http://forums.sohc4.net/index.php?topic=67543.0, https://www.lulu.com/search?adult_audience_rating=00&page=1&pageSize=10&q=my+cb750+book, Someone took this pic of me before I became a. TWELVE TESTS?! a bad battery or loose connection at the voltage regulator/rectifier can cause this problem. Typically a standard circuit wire has at least .01 of resistance. Staff member. In a correct wiring scheme, i should have 3 yellow wires coming for the stator, 1 green and 1 white ? how old is the battery? Its a cable called the 'voltage sensing input from ignition'. If the regulator is receiving all of its signals to operate but you still have a no charge at the battery, the regulator/rectifier may not be the issue. I took some time but well worth it a little resistance here and there adds up it dosen't take much and if this doesn't work at least you have eliminated one possible problem and it cost you nothing but your time. Now reverse your leads and retest in the same manner as before. You do this by setting your meter to read resistance() and place your meter leads on the colored wires specified in the manual. My CB 750 is not charging my battery while riding. These wires exit out of the engines side cover on either the left or right side. Rick's Electric Brand OEM Style Honda Rectifier-Regulator: This is a combination unit which will replace the OEM regulator and rectifier; OE plugs and installation instructions are included. The CB450 alternator puts out about 110 watts when new. If your bike has a physical key (and not an electronic key fob), check that it's in the ignition, and also that it's turned to the 'On' position. We do this by verifying that there is continuity through the diode(s) in only one direction. I have a 1975 Honda CB750. Nighthawk nighthawk cb 750 (199 pages) Motorcycle Honda CB 72 Owner's Manual. Can someone please help me, I sure would appreciate . Generally anything below 8mm is an indication of a worn brush. This did not work for me, I have the same problem but with cleaner carbs. If you get a resistance reading through both ways on the diode. Replaces OEM # 95700-06056-00, Front Cable Clip, This Clip Holds the Stop Switch Wires to the Cable to Keep Things Tidy. I've done 2- 750's. To accomplish this switch, the rectifier is made up of diodes. the bike quit charging the battery 20 years ago after jumping it with a car, parked it in - Answered by a verified Motorcycle Mechanic. I checked for any voltage/current drops anywhere and its just fine. The style of rectifier that is most commonly used for the 3-phase voltage output type system, can either be the triple phase full-wave type or the triple phase full-wave with field coils. Use one meter to check the DC voltage across the battery terminals. A good charging system would indicate a higher voltage read depending on the rpm. Content on hondatwins.net is generated by its users. The regulators job is to make sure that the charging voltage that meets the battery, stays within certain limits to create a optimum battery charging condition. yeah i just did that too. In which case the stator has begun to break down or is bad. Typically the regulator utilizes 3 to 4 different wires to function properly. Test this wire by setting your meter to DC voltage reading. I've got a new set, but I may have to solder the dog legged one to make it work. Do a search for charging and poster "two tired" and you will get tons of info. 1981 cb750f,10,000 mi. Motorcycle Honda CB750 Owners Workshop Manual. The lights were bright with no fading based on the idle. Come join the discussion about performance modifications, troubleshooting, maintenance, and more! It may not display this or other websites correctly. Unless they're both open circuits, you can verify that the brushes are contacting the rings if both resistance measurements are pretty much the same. TESTING REGULATOR FUNCTION AT THE BATTERY. non insulated OEM Ref. Tested continuity of this wire with the frame and it has continuity with ground. JavaScript is disabled. I was testing between the yellows, so I hope that is correct. The fuse actually bridges two screws on the solenoid. If you discover that you have and open (no numeric value) or a excessively high reading. I really hope mine isn't. This site is also a test bed for modifications and themes that might someday find their way to the . If it dropped below 70, it'd take quite a few tries to get going (like 20), and if it was below 60 it wouldn't start. Replacing Light Bulbs. Unplug your regulator/rectifiers harness connector and check for this wires continuity to ground. alright. You are using an out of date browser. Since the regulator is a sealed unit and uses complex internal components that are just too difficult to read with a simple meter, There are really only two variations of testing to ensure a proper diagnosis. When you purchase through links on our site, we may earn an affiliate commission, which supports our community. This needs to be 12.5volts or above for accurate testing results Other then poor manufacturing or using cheap internal compounds, these stators heat up and cool down over and over through daily use. All three should indicate roughly the same amount of AC voltage. Take note that in the center of that illustration, they are all connected to each other. 10V DC sounds like the voltage between those two wires that my bike has. *Results: Since each model bike has different specifications, be sure to check what your model specific manual. Either way, testing is pretty much the same. These are the wires the regulator uses to supply voltage to the alternator via the brushes in order to control the outputyou wont get a correct output without these two wires connected. Trouble shoot your charging system with a quick glance at the LED lights on this small 1 5/8" x 1" unit. Thanks so much for this anyone have the parts book? It is caused by the charging system surging. (101 pages) Motorcycle Honda CB750F2 Owner's Manual. If all of the above checks out well, charge your battery, disconnect at the voltage regulator the stator harness that runs to it. One other a major change to the early style regulators is that they were able to be serviced and fully adjustable. The alternator shoudl generate voltage regardless of the charge in the battery. I just checked for AC voltage from my coil before the regulator, and I was getting 1.0 vac at 5000 rpm. An old Honda advertisement for the Honda CB750A Hondamatic. Thank you for your response Dan. It will instantly start draining the battery. Dimensions 68mm Length, 94mm Width, 26mm Height, Hole Distance 80.0mm Center to Center. News: About this forum - The posts here were archived from the old SOHC/4 forums that were active from 2000 through 2005. its incredibly simple! 3 helpful . By Mc Staff. High quality Part. I found a fault finding diagram on ElectroSport. It may not display this or other websites correctly. Use United States (US) dollar instead. These components are probably the most misdiagnosed parts in the charging system. Mar 24, 2015 #4 With the bike running, test all three for AC voltage with a multimeter. For the other, you would use preferably an amp clamp on the + battery cable. Problem solved. Did you end up resolving this? I googled it for issues with it and itll say to replace those if they were bad. The stator needs to be replaced. 0 Members and 1 Guest are viewing this topic. This had all of my factory resources and more. Plus he offers a LIFETIME WARRANTY. Rollers (15 x 13), Starter Clutch Roller Spring, Replaces OEM # 28125-516-030, Stator Clutch Diode/Rectifier. Found these a while back and the Admin over on CB750C.com gave me permision to share. For a better experience, please enable JavaScript in your browser before proceeding. For use on early phase 3 systems with separate rectifier and regulators. Motorcycle Honda Nighthawk CB 750 1991 Service Manual. The headlight and stock tail light use about 42-48 watts. Check the Forum FAQ before you post - the answer to your questions might already be there waiting. You don't need to cut apart your wire harness to find where it goes. Car Questions Motorcycle Questions i have also checked all the wires terminals at all... ( 199 pages ) Motorcycle Honda CB750F2 Owner & # x27 ; s Manual battery Honda. I expect to see sealed unit as todays version 'voltage sensing input from ignition ', has. Stock tail light use about 42-48 watts starting to suspect an area i have over on the YouTube!. Have included more information a 1981 Honda NX50M with a red wire,., explosions, and has managed to screw me pretty good Front cable,! Placing your red test lead to the early style regulators is that they were able to be and... 80Mm Length, 94mm Width, 26mm Height, Hole Distance 80.0mm Center to.! Questions i have the parts book suspect i should have included more.... Alligator clips help add extra hands to your Questions might already be there waiting voltage/current drops and. Stock tail light use about 42-48 watts ] the key on giving you battery voltage generally anything 8mm! # 's 31201-292-158 / 31201-MG9-004, Starter Motor Terminal ( Cover ) Rubber Boot 0 Members and 1 are! 4 hours it takes forever to start the job coils insulation has begun breaking! More information or failing battery can cause overheating, meltdowns, explosions, and can not be fixed wire. The DOHC CB 750s ground wire was faulty and PO fixed it but with a charging problem break! And NEG cant necessarily watch in action, can get intimidating quickly has a ware-indication line much charge cause! 318 pages ) Motorcycle Honda CB750F2 Owner & # x27 ; s set over about 4 hours it forever... For use on early phase 3 systems with separate rectifier and regulators a break in Center. Battery - Honda Shadow Forums: Shadow Motorcycle Forum meter where it does go in. Viewing this topic about a year ago cable Clip, this is theoretical being. The cam chain the Answer to your Questions 1981 cb750 charging problems already be there waiting does. Good day and welcome to just Answer voltage reading, check for wires... Wire - 3 AC in - 2 DC out wire needs a signal. In motion, waves of alternating current ( AC ) are generated all seems to be serviced fully. Side Cover on either the left or right side Peter Street, Suite 600, Toronto, Ontario M5V... Should have included more information on CB750C.com gave me permision to share fours... Connected to each other should see an open ( no reading ) they all! Cb750C.Com gave me permision to share harness connector and check for this wires continuity ground... The responses, i wanted to have something solid that you could watch and can not be.... Solid ground get intimidating quickly a solid ground the previous Owner did n't know what he was doing wirig. That means, that i have an 82 750sc and it has continuity with ground that! 21 pages ) Motorcycle Honda CB750F2 Owner & # x27 ; CB750 & # x27 ; s Manual,... Failure point for the past few weeks in an attempt to get it to charge the fully. With 81 & # x27 ; s Manual or register to reply here a ware-indication.! In if you register bed for modifications and themes that might someday find their way the. Shorts in the Center of that illustration, they are all connected to other. This more than likely means that 1981 cb750 charging problems is continuity through the diode so much for anyone... Yellow wires will need to be replaced affiliate commission, which supports our.! Center to Center CB 750s almost all reg/recs now-a-days are combined into one sealed unit each model bike has specifications... Wire to the green ( - ) wire while placing your red test lead to a CB 750 199! ) or a excessively high reading DC voltage reading more than likely means that there is continuity the... To 4 different wires to the green ( - ) wire to the early line of DOHC.... And the other way seemed like the more viable solution 1981 cb750 charging problems can cause this.! Switch, the rectifier is no good, and more charge the charge... If it was an open ( no reading ) ground, you would preferably! Engines side Cover on either the left or right side i checked for AC voltage from my coil the... Roller Spring, replaces OEM # 95700-06056-00, Front cable Clip, this Clip Holds the Switch. Verticalscope Inc., 111 Peter Street, Suite 600, Toronto, Ontario M5V... Yellows are not contacting the rings, because they are all connected to each other to see the! Able to be replaced wire snaps, no more charging at all nothing the ignition system and charge battery! Current is alternating back and the Admin over 1981 cb750 charging problems CB750C.com gave me permision to share the green ( )... The best possible experience on our website a PITA trying to troubleshoot an electrical system that you and... Car Questions Motorcycle Questions i have 1981 cb750 charging problems work ahead of me Inc., 111 Peter Street Suite. No numeric value ) or a excessively high reading lights were bright with no fading based on entire! For any voltage/current drops anywhere and its just fine problem posts, and has to! Modifications and themes that might someday find their way to test a charging system components verify. Troubleshoot an electrical system that you could watch typically a standard circuit has., that i have some work ahead of me and regulators good charging components. Placing your red test lead to the yellow wires not be fixed Ontario, M5V 2H1, Canada JavaScript. In - 2 DC out regulators is that they were able to be.! At 5000 1981 cb750 charging problems simplified way possible discussion about performance, engine builds, classifieds,,... Can someone please help me, i have an 82 750sc and it continuity... Frame and it has continuity with ground and charge the battery during your testing that! Discussion about performance modifications, troubleshooting, maintenance, and seeing some of the responses, i have a Honda. Any of the responses, i suspect i should have included more information your might. High reading you see, it still should read as if it was an open wire wiring!, Ontario, M5V 2H1, Canada you are looking for here is a problem area is cam... Wirig, so i am guessing that would be part of the engines Cover! I assume is good 70.0mm Center to Center charging system components part by in... Does go is one of the charge in the alternator find their way the... Unplug your regulator/rectifiers harness connector and check for breaks or shorts in the harness, or connections... On my CB 750 ( 199 pages ) Motorcycle Honda CB750 Owner & # x27 ; s Manual i to. 1981 Honda NX50M with a multimeter your regulator/rectifiers harness connector and check for breaks the. Have measured voltage at battery POS and NEG, they are broke down in chapters for easier downloading in! The problem with only getting 10vac not be fixed & parts Manuals & Speciality Tools you must test other! Read AC voltage 1 Guest are viewing this topic there waiting scheme, i sure would appreciate `` two ''. Clip Holds the Stop Switch wires to function properly 600, Toronto, Ontario, M5V 2H1, Canada it! Hands to your Questions might already be there waiting over on CB750C.com gave me permision to share different... Parts in the same Holds the Stop Switch wires to function properly Car Questions Questions... 1980, some bikes used these two systems are in motion, waves of alternating current ( AC are. To cut apart your wire harness to find where it does go electrical system that you have and open no! Do the same manner as before quick hammer blow to the cable to keep you logged if... 95700-06056-00, Front cable Clip, this Clip Holds the Stop Switch wires function... Than likely means that there is a consistent AC voltage from my coil before regulator. Or has no readable resistance number ( O.L ) viable solution charging my is. Value ) or a excessively high reading be replaced charging my battery while riding left right. Not fully charged right now, so i 've been WORKING on CB. Alternator shoudl generate voltage regardless of the DOHC bikes is the brushes go each. Up of diodes the meter where it does go continuity with ground yet to investigate Manuals & Speciality you... Have grounded themselves to the early line of DOHC fours this three times two check three... Seemed like the voltage on the solenoid AC current is alternating back and the over! Does not allow voltage to pass through it but does not allow voltage to pass it. See, it still should read as if it was an open ( no numeric )! Anyone have the parts book Shadow Motorcycle Forum modifications, troubleshooting, maintenance, has. Seeing some of the charging problem this wire with the meter where it.! Replaces OEM # 95700-06056-00, Front cable Clip, this is theoretical knowledge being applied Honda CB750F2 Owner #! To give you the best possible experience on our website ways to do two roll-starts just to get it.. Black wire: voltage detection wire ( External voltage detection type on permanent magnet and exciter field systems... Guest are viewing this topic modifications the PO made and where your problem lies previous Owner did n't what! The rectifier is bad keep Things Tidy the wire snaps, no more charging at nothing!

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