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. This is really getting frustrating. 1981 CB750K (a bunch of parts in boxes) Tim Administrator. JavaScript is disabled. Thanks so much for this anyone have the parts book? Sbartram91; Jun 10, 2020; Electrical; Replies 14 Views 4K. Once it comes in contact with this one way valve, the rectifier takes the negative wave portion, and flips it into a positive wave. The Real Housewives of Atlanta The Bachelor Sister Wives 90 Day Fiance Wife Swap The Amazing Race Australia Married at First Sight The Real Housewives of Dallas My 600-lb Life Last Week Tonight with John Oliver It is caused by the charging system surging. Honda CB750 (69-78) Rick's Electrics Complete Refurbished Charging Systems NEW Cycle X "High output 20 amp system" . (The bike does not need to be running to do this test). Apr 08, 2010 2003 Honda CB 750 Nighthawk. CHARGING SYSTEM So you think that your bike is not charging correctly. Volt Amp Ohm meter with diode and continuity test, Alligator clips help add extra hands to your testing scenario. This has the OEM type ground wiring and Stock Type Plugs. A fully charged lead acid battery should have 12.7 to 12.9 volts sitting. Take note that in the center of that illustration, they are all connected to each other. This did not work for me, I have the same problem but with cleaner carbs. Anyway the DOHC CB 750s are known for really bad electrics. hondatwins.net is an independent Honda enthusiast website owned and operated by VerticalScope Inc. Power: 39hp @ 7,500rpm (rear wheel , period test) Top speed: 97mpg (period test) Engine type: 736cc air-cooled OHC inline four. ossiliscope shows a rpm-dependent 9-15Vpp on all phase combinations. Black wire: Voltage detection wire (External voltage detection type on permanent magnet and exciter field type systems only). You will receive a reminder when the product becomes available Batteries can not store AC voltage. We also know that in order for a battery to maintain and drain its usable energy over and over again, It needs to be charged. 2. . Its in near mint condition, only has about 27k miles on it. Returning back to DTT it puts a smile on my face to read these posts from my old thread. All these wires are then connected to a big plug which is located on the main harness. Like 850 outbound clicks to CB750C.com WEEKLY. 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. The LED status will indicate voltage regulator or alternator problems. But, see with the meter where it does go. The specific value of this number differentiates from bike to bike. alternator not charging battery - Honda Shadow Forums : Shadow Motorcycle Forum. May 5, 2022 #3 . Other then poor manufacturing or using cheap internal compounds, these stators heat up and cool down over and over through daily use. JavaScript is disabled. So I bought a 1981 CB750 about a year ago. Logo merchandise is available at the SOHC/4 Shop. These readings should be closely in range of each other. When you purchase through links on our site, we may earn an affiliate commission, which supports our community. With the connector still unplugged, test this wire by setting your multimeter to DC voltage. [] the key on giving you battery voltage? The stator needs to be replaced. A low or failing battery can cause crazy readings during your testing. Your right about the holder. You don't need to cut apart your wire harness to find where it goes. Starter Clutch Rebuild Kit - KIT contains: 3 pc. A forum community dedicated to all motorcycle owners and enthusiasts. 22v at idle up . Im pulling my hair out. How to Fully Troubleshoot Your Motorcycle Charging System https://motorcyclemd.com/ MotorcycleMD is online now Quote Quick [], We noticed you're visiting from Germany. This can be an indication of the coils insulation has begun to breaking down or has been overheated. 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. im gonna hook the ac gen up to an oscilliscope and see wtf's goin on. Ill be waiting to hear from you before taking further action Why do you think your rotor is bad? 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. resistance or continuity through the stators windings. This charging problem started two weeks ago, and has managed to screw me pretty good. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register. Messages 1 . Thisrocks. I had to do two roll-starts just to get it home. Two ways to do it: as far as the brushes go, each one has a ware-indication line. Mine still doesn't produce enough voltage to charge the battery below 2,000rpm. 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 checked them. If it doesn't then you might have to start tracing physically. 1.Green wire: Grounds the system to the frame (may have two wires). Remember that your testing the actual regulator/rectifier harness this time, and not the main wire harness. Nighthawk nighthawk cb 750 (199 pages) Motorcycle Honda CB 72 Owner's Manual. The Fora platform includes forum software by XenForo. Once the wire snaps, no more charging at all nothing. 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. 3. When either of these two systems are in motion, waves of alternating current (AC) are generated. Unplug your regulator/rectifiers harness connector and check for this wires continuity to ground. *Results: The goal here is to make sure that a resistance reading is noted in only one direction of each diode. John DeMaria's '74 CB750K Happy Customers 8782808780 Since 2010 Important Product Safety Notice Series 1: Electrical Ignition Systems, Ignition Switch, Coils, Plugs, Contact Points Headlamp, Bulbs & Parts Turn Signal Lamps, Stems, Lenses & Reflectors Tail Lights - OEM Type Tail Lights - Aftermarket/Custom Switches & Sensors Handlebar Switches what kind of voltage do you get at the battery running ~4000 rpms? Thread starter MIkeZad; Start date Jul 2, 2021; M. MIkeZad CB750 New member. With the bike running at operating temperature. 1971 CB750K1 (newest bike), 1996 Royal Enfield 500 Bullet (therapy bike), 1981 Yamaha XV920RH, 2006 Kawasaki Concours (retirement bike), 1975 Yamaha RD350 (race bike), 1989 Honda VTR250 Interceptor (race bike), 1986 Kawasaki EX250 Ninja (race bike in progress), 1985 Honda Elite CH250, 1973 Yamaha GT1 80cc, 1974 Yamaha DT360 project bike. Designed with a lower voltage set point to work with lithium ion batteries only. For a better experience, please enable JavaScript in your browser before proceeding. Do a search for charging and poster "two tired" and you will get tons of info. A forum community dedicated to Honda Twin cylinder motorcycle owners and enthusiasts. The rest is left to run the ignition system and charge the battery. Start your motorcycles engine and place your red (+) lead to either one of the three yellow wires by back probing into the connector. You are using an out of date browser. open circuit) then you know that the brushes are not contacting the rings, because they are too worn down. Voltage will drop as the battery becomes charged, I would hate to think you did all that work for a normal condition ?? how old is the battery? Test the AC voltage from the stator wires three yellow should get about 26v ac. Can someone please help me, I sure would appreciate . Honda CB750A Hondamatic. For the other, you would use preferably an amp clamp on the + battery cable. 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. It may not display this or other websites correctly. I've had it for 2 years, and for about 1.5 of those years, I had no issues. Another thing that is a problem area is the cam chain . It wouldn't charge and this was after replacing all of the electrical components. 1981 HONDA CB650Z / A - chain drive 1981 HONDA CB750F/F2 . when you replaced the one originally on your 750 did you get a new one? Keep in mind that this process is happening faster then you can see. The 1st was a '78 SOHC. Typically a standard circuit wire has at least .01 of resistance. It fluctuates 12-12.5V v depending on the battery charge and the rpm. Dynatek Charge Monitor. 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. I bought a 1981 CB750 last fall. FIY: Because the stator is putting out so much electrical AC energy, the stator is typically the most common component to either fail or cause other issues down the line. 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. This charging problem started two weeks ago, and has managed to screw me pretty good. TESTED ALTERNATOR SEEMS TO BE WORKING Answered in 12 minutes by: The LED status will indicate voltage regulator or alternator problems. Spins off the revolutions of the crankshaft. Honda CB750A Hondamatic. Stock Honda cb750 charging systems are approx. You can do this test by first setting your multimeter to read AC voltage. http://www.bikeexif.com/honda-cb450-restoration. (21 pages) Motorcycle Honda CB750F2 Owner's Manual. 10V DC sounds like the voltage between those two wires that my bike has. Either way, testing is pretty much the same. Rectifier-Regulator: This is a combination unit which will replace the OEM regulator and rectifier. The engine is the 1.5-liter A-series four-cylinder, rated at 65 horsepower. Do this with all three of the yellow wires. It is over charging and buring out all bulbs. Replaces OEM # 45465-270-000, Alternator Cover Gasket (Dyno Cover) - OEM # 11397-300-306, Alternator Stator Wire Harness, This Harness has the Same 7 Wire Plug as the OEM part and Hooks up Without Alterations. i doused pretty much the whole bike in contact cleaner to no avail. Honda 1981 CB 750 - Battery keeps going dead. Wow, looks like I am not the only one with problems. The Charge Monitor allows easy determination of the operational state of the charging system with a quick glance at the indicator LED's. The Charge Monitor can be used on any vehicle with a 12 volt battery/charge system and has 3 indicator LED's to show the charge status: red, amber and green. We use cookies to give you the best possible experience on our website. Did you end up resolving this? I'm running out of ideas. 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. Plus he offers a LIFETIME WARRANTY. At 4K RPM it gets about 14.4 volts. with insulated leads & 1pc. Headlight on it shows battery voltage at idle speed. CB750 charging problem HELP!! 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. OK, new stator is in and no difference. *Results: You should see a standard resistance reading (depending on the specifications noted in manual) between .001 up to .9 . Let me explain. The fuse actually bridges two screws on the solenoid. I really hope mine isn't. This outcome needs to be the same on every diode you test. Rick's Electric Brand OEM Style Honda Rectifier-Regulator: This is a combination unit which will replace the OEM regulator and rectifier; stock type plugs and installation instructions are included. The rectifier is bad and will need to be replaced. Since AC current is alternating back and forth from positive to negative in its own waveform. Keeping money in your pocket from avoiding the shot-gun approach whenever a charging system problem arises. 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. 1. It may not display this or other websites correctly. It will instantly start draining the battery. 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. Also Be sure to check out these videos that I have over on the YouTube channel! Staff member. I have also checked all the wires terminals at it all seems to be just fine. This is a combination unit which will replace the OEM regulator and rectifier; stock type plugs and installation instructions are included. I have a 1981 Honda NX50M with a charging problem. This needs to be 12.5volts or above for accurate testing results News: About this forum - The posts here were archived from the old SOHC/4 forums that were active from 2000 through 2005. Record your readings. We will break down the charging system components part by part in the most direct and simplified way possible. If they havent, then on each reading you should get NO numeric resistance readings on your meter whatsoever. Dimensions 80mm Length, 94mm Width, 27mm Height, Hole Distance 70.0mm Center to Center. HAVE A CHARGING PROBLEM. In which case the stator has begun to break down or is bad. 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. Years produced: 1976-78. right ? you will do the same exact troubleshooting procedure on the green (ground) wire to the same three yellow wires. High quality Part. Messages 4 Reaction score 0 Points 1 Location London. When you purchase through links on our site, we may earn an affiliate commission, which supports our community. Dismiss. This was a lifesaver! 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. 3 helpful . This means that the regulator is regulating the excessive voltage away from the battery once optimum charging output has been met. Failure to have this signal can result in a no charge or charging a system malfunction. 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 . 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. Then you can test the yellow wires. These wires exit out of the engines side cover on either the left or right side. Now, would it be possible that if the motorcycle overheats it drops to charge? *Results: This wire should have constant battery voltage even with the key off. I've got a new set, but I may have to solder the dog legged one to make it work. The Fora platform includes forum software by XenForo. Cylinders #1 and #2 have spark, but will not burn. 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). Locate the stators wire harness connector and make it easily accessible. Thank you for your response Dan. Though some folks here may be able to advise I'd recommend checking out the SOHC4 forum. They are not serviceable, and if a problem is found with either systems. It allows voltage to pass through it but does not allow voltage to reverse its direction back the other way. enough is enough!. I'm having the same problem.. Wez_ C. Reg/rec . In a correct wiring scheme, i should have 3 yellow wires coming for the stator, 1 green and 1 white ? 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. Anyone with info let me know. You are using an out of date browser. It may show 13.6 immediately after charging, but that is called a surface charge, and drops pretty quickly. Can someone help me? I am thinking vacuum or gas but I am stumped. The rectifier needs to be unplugged with no voltage running through it. This more than likely means that there is a break in the windings. Set your multimeter to read resistance(). You will not get that from any electrical parts supplier. So I've owned this bike for about 4 months and it's had this issue from the beginning. You should only read battery voltage once the key is turned to the on position. Shop & Parts Manuals & Speciality Tools You must log in or register to reply here. 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). High quality Part. Higher rpm blinker light fine> Battery is fully charged any thoughts as to what is causing this? This post helped a lot of people out maybe have a look? The stator needs to be replaced. You will do this test three times on each of the three yellow wires. Trouble shoot your charging system with a quick glance at the LED lights on this small 1 5/8" x 1" unit. To accomplish this switch, the rectifier is made up of diodes.