(101 pages) Motorcycle Honda CB750F2 Owner's Manual. It also appears the previous owner didn't know what he was doing with wirig, so I have some work ahead of me. Designed with a lower voltage set point to work with lithium ion batteries only. 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. Volt Amp Ohm meter with diode and continuity test, Alligator clips help add extra hands to your testing scenario. Head Light Beam Adjustment. The rectifier needs to be unplugged with no voltage running through it. Check both over. resistance or continuity through the stators windings. I checked them. I have measured voltage at battery POS and NEG. At the first start, assuming it's set over about 4 hours it takes forever to start. Replaces OEM # 32411-230-000, Starter Motor Flange Bolt Set/2. I think the break even point for me (not charging or discharging) is around 3000-3500 rpms. '74 "Big Bang" Honda 750K [836]..'71 Honda 750K project..'76 Honda 550F..K3 Park Racer!and a Bomber!plus plus plus Have you looked at your bike's color diagram? Its pretty crazy. Faulty connection can result with no charge to battery, or other charging failures. Red or red/white wire: Battery voltage (may have two wires). 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. I will replace this one soon with a better shot! 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. LED Charging system indicator Gauge. JavaScript is disabled. 1.Green wire: Grounds the system to the frame (may have two wires). It may not display this or other websites correctly. I am thinking vacuum or gas but I am stumped. 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. 2. We know that current is produced from the spinning motion of the alternator, as RPMs increase so does the AC voltage output. With the connector still unplugged, test this wire by setting your multimeter to DC voltage. [] the key on giving you battery voltage? Did you end up resolving this? It is caused by the charging system surging. I believe that bike is one of the early line of DOHC fours. 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. If this fuse is blown,it will shut down the bike, since it is the main fuse. Read full answer. With it connected I was getting 10vac @ 5000 rpm between the yellows. Once it comes in contact with this one way valve, the rectifier takes the negative wave portion, and flips it into a positive wave. This had all of my factory resources and more. Typically a standard circuit wire has at least .01 of resistance. 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. 3. alternator not charging battery - Honda Shadow Forums : Shadow Motorcycle Forum. It fluctuates 12-12.5V v depending on the battery charge and the rpm. I was testing between the yellows, so I hope that is correct. 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. Motorcycle Honda CB750 Owners Workshop Manual. This NEEDS to be correctly charged and tested before you start and troubleshooting. We will break down the charging system components part by part in the most direct and simplified way possible. He will fix you right up. 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. 22v at idle up . The "proper" way to test a charging system is to use a two meter test. 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. Then you can test the yellow wires. So I've owned this bike for about 4 months and it's had this issue from the beginning. The 1st was a '78 SOHC. Yeah man, test the rotor. I've had it for 2 years, and for about 1.5 of those years, I had no issues. Come join the discussion about performance, engine builds, classifieds, modifications, troubleshooting, maintenance, and more! Rollers (15 x 13), Starter Clutch Roller Spring, Replaces OEM # 28125-516-030, Stator Clutch Diode/Rectifier. open circuit) then you know that the brushes are not contacting the rings, because they are too worn down. Come join the discussion about performance modifications, troubleshooting, maintenance, and more! Years produced: 1976-78. Spins off the revolutions of the crankshaft. 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. CB750 charging problem HELP!! Talk to Tony at Oregonmotorcycleparts.com. It is over charging and buring out all bulbs. 10VAC sounds a tad low. 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. You must log in or register to reply here. Use one meter to check the DC voltage across the battery terminals. By Mc Staff. 3. New Bike Owner with charging problem. The specific value of this number differentiates from bike to bike. its incredibly simple! Repeat this two more times, only moving your black test lead to the other yellow wires. A forum community dedicated to all motorcycle owners and enthusiasts. The Cycle X "high-output" charging systems will allow you to use many . May 5, 2022 #3 . Keeping money in your pocket from avoiding the shot-gun approach whenever a charging system problem arises. I googled it for issues with it and itll say to replace those if they were bad. Fuel on, any combination of carbs 2, 3, 4 will bleed gas endlessly. Test this wire by setting your meter to DC voltage reading. When you purchase through links on our site, we may earn an affiliate commission, which supports our community. This is a combination unit which will replace the OEM regulator and rectifier; stock type plugs and installation instructions are included. Hello, my name is Edgar, How are you all doing? I did some searching, and so far was unable to find a posting that clearly relates to my problem. When I first got it, it ran great if started in hot weather. The insulation breaks down and causes these parts to fail, or make a short to ground. After cleaning I used dialectic grease on all and my charging system is working great. JavaScript is disabled. http://www.bikeexif.com/honda-cb450-restoration. This indicates that your stators coil winding insulation has burnt up and/or deteriorated and will need to be replaced. You are using an out of date browser. Good luck D Darryl thompson CB750 New member Messages 4 Reaction score 0 Points 1 Location Madras or 97741 Aug 21, 2022 #3 I will go pull the cover now and test the contact rings directly now. These components are probably the most misdiagnosed parts in the charging system. This charging problem started two weeks ago, and has managed to screw me pretty good. 10V DC sounds like the voltage between those two wires that my bike has. Now rev the motorcycles rpms up to around 3,000 rpms and hold. Keep in mind that this process is happening faster then you can see. Ride Safely, Ed. For a better experience, please enable JavaScript in your browser before proceeding. The Fora platform includes forum software by XenForo. JavaScript is disabled. First, I'm not receiving any compensation. We do this by verifying that there is continuity through the diode(s) in only one direction. If not, check for breaks in the harness, or loose connections. Black wire: Voltage detection wire (External voltage detection type on permanent magnet and exciter field type systems only). Dimensions 68mm Length, 94mm Width, 26mm Height, Hole Distance 80.0mm Center to Center. I've got a new set, but I may have to solder the dog legged one to make it work. There is something about trying to troubleshoot an electrical system that you cant necessarily watch in action, can get intimidating quickly. If you get a resistance reading through both ways on the diode. Plenty videos on u tube. A diode in its simplest form, is considered to be a one way valve for electricity. We use cookies to give you the best possible experience on our website. Fits: All Honda CB750's (1970-78) Part #: 24-2032 USD$51.75 ea Rectifier Only - Solid state type. 0 Members and 1 Guest are viewing this topic. My CB 750 is not charging my battery while riding. It may not display this or other websites correctly. Now switch your meter leads and retest. Alternator Rotor Puller - 20mm x M1.5 Right Hand Thread Puller for pulling internal thread rotors. You repeat this three times two check all three wires. 3 helpful . I've done 2- 750's. Test the AC voltage from the stator wires three yellow should get about 26v ac. Its in near mint condition, only has about 27k miles on it. Battery Charging. It may show 13.6 immediately after charging, but that is called a surface charge, and drops pretty quickly. 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. I ride a 1980 Honda CB750 Custom. #3 and #4 burn pretty hot, to the point the pipes actually smoke (we've assumed it was gas/oil on the pipe itself). There is a very effective way to see if your battery has any excessive draw on it while the key is off. Black meter lead to the green(-) wire while placing your red test lead to the yellow wires one at a time. Since AC current is alternating back and forth from positive to negative in its own waveform. Any gurus around right now? VerticalScope Inc., 111 Peter Street, Suite 600, Toronto, Ontario, M5V 2H1, Canada. Besides the dog, the test light is a mans best friend. You should soon discover what modifications the PO made and where your problem lies. They can also be found in the center of the alternating system like on the older CB750s The headlight and stock tail light use about 42-48 watts. So I bought a 1981 CB750 about a year ago. How do I test the rotor? If you get a wire that is out of limit or has no readable resistance number (O.L). Stop Light Switch Adjustment. 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. VerticalScope Inc., 111 Peter Street, Suite 600, Toronto, Ontario, M5V 2H1, Canada. I use these almost everyday Im on the job. Rectifier Only - 3 phase - 5 Wire - 3 AC in - 2 DC out. . Issues with DOHC CB750 Carbs? Place your meters black (-) lead to a solid ground. Tested continuity of this wire with the frame and it has continuity with ground. The rest is left to run the ignition system and charge the battery. Honda CB750A Hondamatic. I checked for any voltage/current drops anywhere and its just fine. For a better experience, please enable JavaScript in your browser before proceeding. After reading several of the charging problem posts, and seeing some of the responses, I suspect I should have included more information. This can be an indication of the coils insulation has begun to breaking down or has been overheated. Sbartram91; Jun 10, 2020; Electrical; Replies 14 Views 4K. #'s 31201-292-158 / 31201-MG9-004, Starter Motor Terminal (Cover) Rubber Boot. HAVE A CHARGING PROBLEM. 13.5 amps and are prone to be even lower with old wires and poor connections. Anyway the DOHC CB 750s are known for really bad electrics. enough is enough!. 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. You do this by setting your meter to read resistance() and place your meter leads on the colored wires specified in the manual. 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. 3. alright. Do this with all three of the yellow wires. Generally anything below 8mm is an indication of a worn brush. Messages 4 Reaction score 0 Points 1 Location London. You do this by setting your meter to read resistance() and place your meter leads on the colored wires specified in the manual. The fuse actually bridges two screws on the solenoid. TESTING REGULATOR FUNCTION AT THE BATTERY. How to Fully Troubleshoot Your Motorcycle Charging System https://motorcyclemd.com/ MotorcycleMD is online now Quote Quick [], We noticed you're visiting from Germany. You will not get that from any electrical parts supplier. 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. The lights were bright with no fading based on the idle. You may also get a very high resistance reading. In which case the stator has begun to break down or is bad. Thanks. They are broke down in chapters for easier downloading. Later model addendums and specific wiring diagrams are at the bottom. So, I have a 1980 CB 750 costume. Charging System/Alternator: Service Information, Troubleshooting 155; Related Manuals for Honda CB750F2. This was a lifesaver! Motorcycle Honda CB750F2 Owner's Manual . Returning back to DTT it puts a smile on my face to read these posts from my old thread. , Pre 1980, some bikes used these two systems as separated units. 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. Battery Stores regulated DC current. with insulated leads & 1pc. For the other, you would use preferably an amp clamp on the + battery cable. (318 pages) Motorcycle Honda CB750F2 Owner's Manual. Can be mounted as shown or to handlebar by clamp (included). The Permanent magnets are used inside the walls of the common flywheel, spinning with the revolutions off the crankshaft and creating a magnetic field. You're not going to make it home. If you discover that you have and open (no numeric value) or a excessively high reading. If it doesn't then you might have to start tracing physically. It wouldn't charge and this was after replacing all of the electrical components. The stators and rotors go out all the time. 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. To little charge will gradually kill your battery. Thisrocks. Wow, looks like I am not the only one with problems. Login with username, password and session length. I use one like this that gives you a Digital voltage read out. If all of the above checks out well, charge your battery, disconnect at the voltage regulator the stator harness that runs to it. Some more pics, checked everything again: After reading in the forum, it seems that the first issue to check if my battery voltage is not increasing with the rpm is the alternator. Regulator Regulates voltage so that it stays within the specified range. 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. This more than likely means that there is a break in the windings. Honda CB750 (69-78) Rick's Electrics Complete Refurbished Charging Systems NEW Cycle X "High output 20 amp system" . This can be an indication of the coils insulation has begun to breaking down or has been overheated. Do a search for charging and poster "two tired" and you will get tons of info. Messages 1 . News: About this forum - The posts here were archived from the old SOHC/4 forums that were active from 2000 through 2005. 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. I really hope mine isn't. The whole unit must be replaced as one. Record your readings. I wish i knew what the right number was, but i dont - i get about 14VAC at 5 grand OK, the other 2 wires in that connector were giving me 10VDC, but I was only getting 10VAC from the yellows. 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). 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. 1981 cb750f,10,000 mi. These wires exit out of the engines side cover on either the left or right side. 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. Disconnect the stators wire harness connector. For use on early phase 3 systems with separate rectifier and regulators. 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Differentiates from bike to bike 12-12.5V v depending on the + battery cable over about 4 hours takes... Has any excessive draw on it while the key is off red/white wire: voltage... The first start, assuming it & # x27 ; s Manual use a two meter test the shot-gun whenever... Have included more information is produced from the spinning motion of the responses, i have some work ahead me... Starter Motor Flange Bolt Set/2 bad electrics you discover that you cant watch. Cb750 about a year ago other websites correctly with ground n't know what he was doing with,... All bulbs this was after replacing all of the early line of DOHC fours to,!