Gauge is Bright High Quality Chrome plated and clamps onto 7/8" Bars and can be easily wired into any point in the system (before a switched load is best). The red wire goes from this fuse to the fuse panel in the handlebars, and if that is the only wire that shorted, it should be not too difficult to fix. This is a combination unit which will replace the OEM regulator and rectifier; stock type plugs and installation instructions are included. This site is also a test bed for modifications and themes that might someday find their way to the . TWELVE TESTS?! I dont care how small of a decimal reading you see, it still should read as if it was an open wire. Faulty connection can result with no charge to battery, or other charging failures. BIKE WON'T HOLD 13/14 VOLTS. Keep in mind that this process is happening faster then you can see. I just checked for AC voltage from my coil before the regulator, and I was getting 1.0 vac at 5000 rpm. Other random wires: If your system is designed with an additional field coil (refer to model specific service manual) it will need to be tested as well. You are using an out of date browser. Headlight on it shows battery voltage at idle speed. Never been laid down or anything of that sort. It also appears the previous owner didn't know what he was doing with wirig, so I have some work ahead of me. Remember that your testing the actual regulator/rectifier harness this time, and not the main wire harness. 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. In you do not get a voltage reading, check wire for breaks or shorts in the harness, or loose connections. Place your red(+) lead to one of the yellow stator wires and place the other lead to a different yellow wire in the connector. Rollers (15 x 13), Starter Clutch Roller Spring, Replaces OEM # 28125-516-030, Stator Clutch Diode/Rectifier. If your battery is charging perfectly but your motorcycle still seems to keep killing the battery. Log in SOHC/4 Forum Archives. It fluctuates 12-12.5V v depending on the battery charge and the rpm. If you get a resistance reading through both ways on the diode. If they havent, then on each reading you should get NO numeric resistance readings on your meter whatsoever. I believe that bike is one of the early line of DOHC fours. R/R is only here to capture & regulate the alternator output. TESTED ALTERNATOR SEEMS TO BE WORKING Ask an Expert Car Questions Motorcycle Questions I HAVE A 81 HONDA CB 750. 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. You must test the other charging system components to verify their function to develop your troubleshooting ultimatum. For a better experience, please enable JavaScript in your browser before proceeding. *Results: What you are looking for is continuity (a path) that continues through all three leads. .It has been doing that ever since. Locate the stators wire harness connector and make it easily accessible. i think my problem is in the rotor rather than the stator. Designed with a lower voltage set point to work with lithium ion batteries only. 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. This more than likely means that there is a break in the windings. *Results: This test is to ensure that there are no breaks in that coils wire or any excessive resistance. You are using an out of date browser. I checked them. Use United States (US) dollar instead. 0 Members and 1 Guest are viewing this topic. 250 300 (15 pages) Motorcycle Honda CB72 Shop Manual (175 pages) The stator needs to be replaced. Honda CB750 (69-78) Rick's Electrics Complete Refurbished Charging Systems NEW Cycle X "High output 20 amp system" . 4. Let me explain. Once it comes in contact with this one way valve, the rectifier takes the negative wave portion, and flips it into a positive wave. We show up on loads of google searches now. what kind of accesories (like hotter coils) are you running? He will fix you right up. Do this with all three of the yellow wires. I really hope mine isn't. They are not serviceable, and if a problem is found with either systems. Honda CB750'S Also they have some really awesome moderators there. I suppose that green ground wire was faulty and PO fixed it but with a red wire. A fully charged lead acid battery should have 12.7 to 12.9 volts sitting. There is a very effective way to see if your battery has any excessive draw on it while the key is off. Regulator Regulates voltage so that it stays within the specified range. 1. Registered so I could say thanks, maybe do my part to keep it up. Check both over. Repeat this two more times, only moving your black test lead to the other yellow wires. I checked for any voltage/current drops anywhere and its just fine. Take note that in the center of that illustration, they are all connected to each other. High quality Part. I did notice that one of my yellow wires was pushed out of the connector a bit, so maybe it wasn't making contact. But, see with the meter where it does go. The rectifier needs to be unplugged with no voltage running through it. . So I bought a 1981 CB750 about a year ago. Replaces OEM # 32411-230-000, Starter Motor Flange Bolt Set/2. Because the stators iron core is grounded to the cover or case, once the insulating material on the windings begin to deteriorate it allows the AC current to bypass its route through regulator/rectifier, and takes a shorter path to ground. Cold starting issue with 81' CB750. You do this by setting your meter to read resistance() and place your meter leads on the colored wires specified in the manual. Replacing Light Bulbs. OK, new stator is in and no difference. These readings should be closely in range of each other. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register. It wouldn't charge and this was after replacing all of the electrical components. yes, that is correct, however be sure that you connect the other two wires, white and black. OK, I just tested and got 59 ohms between the 2 brush wires. You will not get that from any electrical parts supplier. With the connector still unplugged, test this wire by setting your multimeter to DC voltage. You are using an out of date browser. Issues with DOHC CB750 Carbs? . Higher rpm blinker light fine> Battery is fully charged any thoughts as to what is causing this? There are several available in the aftermarket though. How to Fully Troubleshoot Your Motorcycle Charging System https://motorcyclemd.com/ MotorcycleMD is online now Quote Quick [], We noticed you're visiting from Germany. CHARGING SYSTEM So you think that your bike is not charging correctly. If this fuse is blown,it will shut down the bike, since it is the main fuse. It may not display this or other websites correctly. The Cycle X "high-output" charging systems will allow you to use many . Place your meters black (-) lead to a solid ground. I bought a 1981 CB750 last fall. It is caused by the charging system surging. Honda 1981 CB 750 - Battery keeps going dead. 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. Rick's Motorsport Electrics has been producing high quality OEM style field coil charging rotor for Honda motorcycles for over 30 years. This can be an indication of the coils insulation has begun to breaking down or has been overheated. Changed voltage regulator - did not help. Content on hondatwins.net is generated by its users. I need to look somewhere else to find my issue. Messages 4 Reaction score 0 Points 1 Location London. In which case the stator has begun to break down or is bad. With the stator harness connector still unplugged and your multimeter still in the resistance () setting, place your red (+) lead to each of the yellow wires while grounding the black (-) lead to a solid ground. The "proper" way to test a charging system is to use a two meter test. The sad thing is that understanding what is this red wire requires cutting all the main harness tapei suspect that this red wire goes to the ignition switch..i should.instead lf a red wire have a green wire that should be grounded as well to get an output from.the alternator if i'm right. 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. I have measured voltage at battery POS and NEG. I did some searching, and so far was unable to find a posting that clearly relates to my problem. So I've owned this bike for about 4 months and it's had this issue from the beginning. VerticalScope Inc., 111 Peter Street, Suite 600, Toronto, Ontario, M5V 2H1, Canada. It is over charging and buring out all bulbs. For a better experience, please enable JavaScript in your browser before proceeding. Battery Charging. The specific value of this number differentiates from bike to bike. It's the weirdest thing - these are by far the most clicked on links on the entire site. Thanks Janie Answered in 8 minutes by: Motorcycle Mechanic: .. Brian : Good day and welcome to Just Answer. Now rev the motorcycles rpms up to around 3,000 rpms and hold. I want this post to shed light on the fundamentals of how to troubleshoot the most popular and common charging system style that Honda uses on their motorcycles. you are looking for is continuity (a path) that continues through all three leads. The Permanent magnets are used inside the walls of the common flywheel, spinning with the revolutions off the crankshaft and creating a magnetic field. Shop & Parts Manuals & Speciality Tools You must log in or register to reply here. Plenty videos on u tube. Red or red/white wire: Battery voltage (may have two wires). Later model addendums and specific wiring diagrams are at the bottom. Good luck, Iam also having the same trouble and mine is a 1980 cb 750f supersport.i ,was wondering if you have a weak spark from bad coils could it possibly put out a weak charge reason I ask is I just noticed one of my coils has a big crack down the length of the coil .I'm sure it s not a good thing but .could it play a role in my charging issue any help is welcome .I'm tired of charging battery all the time.open for new ideas please help me save this ol bike. I am thinking vacuum or gas but I am stumped. So, I have a 1980 CB 750 costume. Once the wire snaps, no more charging at all nothing. *Results: This wire should have constant battery voltage even with the key off. It may not display this or other websites correctly. We do this by verifying that there is continuity through the diode(s) in only one direction. This is our 1981 cb750c, in this video i go through all the problems we had with the build in general, but also go over what has worked jetting wise on getting this bike to run decently with. open circuit) then you know that the brushes are not contacting the rings, because they are too worn down. After installing, I had a constant voltage @ 14v. 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 ? JavaScript is disabled. You need to backtrack to the stator cover, remove left shift cover, and verify what wiring is there. Starter Clutch Rebuild Kit - KIT contains: 3 pc. I will go pull the cover now and test the contact rings directly now. im gonna hook the ac gen up to an oscilliscope and see wtf's goin on. In order for the battery to properly use the output current from the alternator (which is producing waves of AC voltage) the voltage must be changed from AC (alternating current) into DC (direct current). Besides the dog, the test light is a mans best friend. Power: 39hp @ 7,500rpm (rear wheel , period test) Top speed: 97mpg (period test) Engine type: 736cc air-cooled OHC inline four. You're not going to make it home. For the other, you would use preferably an amp clamp on the + battery cable. Just use your multi meter set on ohms, and see if it goes up to where the wring diagram says it should. You may also get a very high resistance reading. This unit will not mount where the old rectifier was, you must find a place to secure it after removing the stock regulator and rectifier. You should only read battery voltage once the key is turned to the on position. Here is a link to a CB 750 forum that covers the DOHC CB 750s. 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!! Remove C first, you may be able to see if the PO hacked into the original wiringLarry, Ok wiring is all good, from the stator and under the cover i have 3 yellow wires, green, white but also the neutral switch wire and the oil pressure wire. Probably should post the voltage readings that have you concerned. Head Light Beam Adjustment. Fits: All Honda CB750's (1970-78) Part #: 24-2032 USD$51.75 ea Rectifier Only - Solid state type. This has the OEM type ground wiring and Stock Type Plugs. The charging system voltage gradually drops off as the engine heats up. Dan. OK, the yellows are not grounded out which I assume is good. Honda CB750A Hondamatic. Please forgive me for this awful video quality, I wanted to have something solid that you could watch. The main thing that will go wrong with the charging system is the rotor. Problem solved. Further increase the rpms to make sure the voltage does not continue to increase out of specification. Nighthawk nighthawk cb 750 (199 pages) Motorcycle Honda CB 72 Owner's Manual. . Another thing that is a problem area is the cam chain . (318 pages) Motorcycle Honda CB750F2 Owner's Manual. Any gurus around right now? The brushes are easy to come by, but the holder is not. [] the key on giving you battery voltage? I ride a 1980 Honda CB750 Custom. This can be an indication of the coils insulation has begun to breaking down or has been overheated. I think the break even point for me (not charging or discharging) is around 3000-3500 rpms. I am thinking maybe my brushes are bad because 1 is a lot more worn down then the other. Plus he offers a LIFETIME WARRANTY. The Rectifier is no good, and cannot be fixed. Failure to have this signal can result in a no charge or charging a system malfunction. It's a PITA trying to deal with this system. I was testing between the yellows, so I hope that is correct. To accomplish this switch, the rectifier is made up of diodes. Spins off the revolutions of the crankshaft. For a better experience, please enable JavaScript in your browser before proceeding. 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. High quality Part. This changes the AC wave to a direct (more controlled) voltage signal. Both worked exactly the same way using the same fundamentals as todays version. Test this wire by setting your meter to DC voltage reading. You should find this site helpful https://www.chinonthetank.com/2011/08/79-82-honda-cb650-charging-problems/ It's for a CB650, but it should still work. After reading several of the charging problem posts, and seeing some of the responses, I suspect I should have included more information. JavaScript is disabled. Also Be sure to check out these videos that I have over on the YouTube channel! Battery Stores regulated DC current. Read full answer. 3. At my wits end with these carbs. Use that. May require a custom mounting job. All these wires are then connected to a big plug which is located on the main harness. Good luck, old wiring sure is a treat. 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. 13.5 amps and are prone to be even lower with old wires and poor connections. Check the Forum FAQ before you post - the answer to your questions might already be there waiting. Start your motorcycles engine and place your red (+) lead to either one of the three yellow wires by back probing into the connector. A low or failing battery can cause crazy readings during your testing. Dimensions 80mm Length, 94mm Width, 27mm Height, Hole Distance 70.0mm Center to Center. Then you can test the yellow wires. Now, would it be possible that if the motorcycle overheats it drops to charge? This more than likely means that there is a break in the windings. Volt Amp Ohm meter with diode and continuity test, Alligator clips help add extra hands to your testing scenario. 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. Common failure point for the charging systems of the DOHC bikes is the brushes or brush holders in the alternator. I found a fault finding diagram on ElectroSport. yeah i just did that too. I've done 2- 750's. There will be three yellow AC wires in the harness. After new battry and voltage reg same problem I cleaned every connection I could find even if they look clean and don't forget the switches kill,starter,blinkers,horn,ignition ect. Voltage will drop as the battery becomes charged, I would hate to think you did all that work for a normal condition ?? It will instantly start draining the battery. Login with username, password and session length. When either of these two systems are in motion, waves of alternating current (AC) are generated. Some ignitions may have multiple positions,. Charging System/Alternator: Service Information, Troubleshooting 155; Related Manuals for Honda CB750F2. Regulators are made up of all sorts of funky semiconducting electrical components that signal, trigger, and meter(regulate) voltage inputs and outputs. A good charging system would indicate a higher voltage read depending on the rpm. There are six diodes total. You repeat this three times two check all three wires. LED Charging system indicator Gauge. Rick's Electric Solid State type Rectifier unit. That means, that I have to charge the battery fully to use it again. #3 and #4 burn pretty hot, to the point the pipes actually smoke (we've assumed it was gas/oil on the pipe itself). Anyone with info let me know. If it doesn't then you might have to start tracing physically. Continue Reading. This needs to be 12.5volts or above for accurate testing results (The bike does not need to be running to do this test). You will do this test three times on each of the three yellow wires. CB750c 1981 weak charge issue. The CB450 alternator puts out about 110 watts when new. For a better experience, please enable JavaScript in your browser before proceeding. 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. We will break down the charging system components part by part in the most direct and simplified way possible. (21 pages) Motorcycle Honda CB750F2 Owner's Manual. I use these almost everyday Im on the job. Apr 08, 2010 2003 Honda CB 750 Nighthawk. Thread starter MIkeZad; Start date Jul 2, 2021; M. MIkeZad CB750 New member. By Mc Staff. 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. You do this by setting your meter to read resistance() and place your meter leads on the colored wires specified in the manual. They are broke down in chapters for easier downloading. This single topic has pulled my trusty and faithful Beast from crates at least 5 times now. Once this signal is read, the regulators job is to either send the excessive voltage straight back to where is came from, short it to ground, or send a signal telling the field coil to stop its output. replaced the OEM rectifier and regulator. The Fora platform includes forum software by XenForo. Good luck D Darryl thompson CB750 New member Messages 4 Reaction score 0 Points 1 Location Madras or 97741 Aug 21, 2022 #3 The LED status will indicate voltage regulator or alternator problems. JavaScript is disabled. Please let me know how your stator works out as soon as you know. Sbartram91; Jun 10, 2020; Electrical; Replies 14 Views 4K. I had a similar problem with my 750. A forum community discussing all bikes from Harley Davidson to Honda, Suzuki, KTM, Yamaha, and BMW. Almost all reg/recs now-a-days are combined into one sealed unit. So I've been working on my CB for the past few weeks in an attempt to get it to charge normally again. I know its an old post just had to say thank you. The voltage on the battery with the bike on fluctuates with RPM but stays significantly below the 14.5 I expect to see. When you switched the leads in the opposite orientation, you should see an open (no reading). check the field coil and stator coils resistance first. 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. 22v at idle up . Other then poor manufacturing or using cheap internal compounds, these stators heat up and cool down over and over through daily use. 10V DC sounds like the voltage between those two wires that my bike has. Universal Solid State Rectifier/Regulator for 3 phase A type Field Excited Alternators with both brushes or both field leads insulated from ground (CB50) Regulates AC output voltage and rectifies charging current. For a better experience, please enable JavaScript in your browser before proceeding. Recommend you use the CB1000C Chapter 18 for the Battery and Charging System instead of the 750 Chapter 16 as it is more informative and has the rotor measuring picture and information . The stator needs to be replaced. Can someone help me? Check the harness for breaks, rusty corroded frame ground, or loose connections (battery terminals included) This can result in a high charging output to the battery and in some cases a no charge scenario. At 4K it shows 13.8 to 14.2 volts. With the bike running at operating temperature. There are 2 different ways that the rotor will shit out: 1) The wire on the rotor will physically snap as seen in the pic below. Batteries can not store AC voltage. As current increases, the regulator waits patiently for the battery to tell it, okay! Test the resistance between the two wires on the connector, then take the alternator cap off and test the resistance between the two rings on the rotor. Trouble shoot your charging system with a quick glance at the LED lights on this small 1 5/8" x 1" unit. *Results: Since each model bike has different specifications, be sure to check what your model specific manual.