I will replace this one soon with a better shot! 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. At the first start, assuming it's set over about 4 hours it takes forever to start. BIKE WON'T HOLD 13/14 VOLTS. He will fix you right up. 1981 HONDA CB650Z / A - chain drive 1981 HONDA CB750F/F2 . 250 300 (15 pages) Motorcycle Honda CB72 Shop Manual (175 pages) The rest is left to run the ignition system and charge the battery. Sep 4, 2020. OK, I just tested and got 59 ohms between the 2 brush wires. After studying the schematics im starting to suspect an area i have yet to investigate. VerticalScope Inc., 111 Peter Street, Suite 600, Toronto, Ontario, M5V 2H1, Canada. The rectifier is bad and will need to be replaced. 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. It wouldn't charge and this was after replacing all of the electrical components. hondatwins.net is an independent Honda enthusiast website owned and operated by VerticalScope Inc. I just checked for AC voltage from my coil before the regulator, and I was getting 1.0 vac at 5000 rpm. Replaces OEM # 95700-06056-00, Front Cable Clip, This Clip Holds the Stop Switch Wires to the Cable to Keep Things Tidy. Plenty videos on u tube. Set your multimeter to the resistance (ohms ) setting. Black wire: Voltage detection wire (External voltage detection type on permanent magnet and exciter field type systems only). First, I'm not receiving any compensation. Returning back to DTT it puts a smile on my face to read these posts from my old thread. 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. I had a similar problem with my 750. 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. Your right about the holder. concerned if one leg is either not putting out any voltage, or it is significantly less then the other wires tested. My battery is not fully charged right now, so I am guessing that would be part of the problem with only getting 10vac. (30 pages) Motorcycle Honda CB750 Shop Manual. 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. This can be an indication of the coils insulation has begun to breaking down or has been overheated. For a better experience, please enable JavaScript in your browser before proceeding. But, see with the meter where it does go. Thisrocks. Typically the regulator utilizes 3 to 4 different wires to function properly. 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. These readings should be closely in range of each other. I ride a 1980 Honda CB750 Custom. Headlight on it shows battery voltage at idle speed. Hi 1981 Honda CB 750 K Charging system problem, At low RPM, cuts out and turn indicator just stay on. Fits: All Honda CB750's (1970-78) Part #: 24-2032 USD$51.75 ea Rectifier Only - Solid state type. You are using an out of date browser. This did not work for me, I have the same problem but with cleaner carbs. . When you purchase through links on our site, we may earn an affiliate commission, which supports our community. Here is a link to a CB 750 forum that covers the DOHC CB 750s. They are not serviceable, and if a problem is found with either systems. 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. *Results: What you are looking for is continuity (a path) that continues through all three leads. Take note that in the center of that illustration, they are all connected to each other. I checked them. Im pulling my hair out. CruiserForums Moderator - Route 66 / American Iron / The Clinic Forums. May 5, 2022 #3 . TWELVE TESTS?! Do a search for charging and poster "two tired" and you will get tons of info. Thanks Janie Answered in 8 minutes by: Motorcycle Mechanic: .. Brian : Good day and welcome to Just Answer. It may not display this or other websites correctly. (The bike does not need to be running to do this test). Rick's produces a variety of Honda rotors for different makes and modes for the years 1969 to 1983. Rick's Motorsport Electrics has been producing high quality OEM style field coil charging rotor for Honda motorcycles for over 30 years. The Cycle X "high-output" charging systems will allow you to use many . Problem solved. Description. This changes the AC wave to a direct (more controlled) voltage signal. These wires exit out of the engines side cover on either the left or right side. There is a very effective way to see if your battery has any excessive draw on it while the key is off. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register. Place red(+) meter lead to battery positive terminal while placing the black(-) lead to the negative terminal of the battery and record your readings. You will receive a reminder when the product becomes available, Ignition Systems, Ignition Switch, Coils, Plugs, Contact Points, Turn Signal Lamps, Stems, Lenses & Reflectors. Now rev the motorcycles rpms up to around 3,000 rpms and hold. 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. Honda 1981 CB 750 - Battery keeps going dead. TESTED ALTERNATOR SEEMS TO BE WORKING Answered in 12 minutes by: You do this by setting your meter to read resistance() and place your meter leads on the colored wires specified in the manual. yeah i just did that too. Wow, looks like I am not the only one with problems. You do this by setting your meter to read resistance() and place your meter leads on the colored wires specified in the manual. 2. I know its an old post just had to say thank you. 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. It may not display this or other websites correctly. Place your meters black (-) lead to a solid ground. *Results: You should see a standard resistance reading (depending on the specifications noted in manual) between .001 up to .9 . i think my problem is in the rotor rather than the stator. Can someone please help me, I sure would appreciate . This needs to be 12.5volts or above for accurate testing results 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. Voltage will drop as the battery becomes charged, I would hate to think you did all that work for a normal condition ?? For a better experience, please enable JavaScript in your browser before proceeding. You may also get a very high resistance reading. Messages 1 . Thanks. You are using an out of date browser. 10VAC sounds a tad low. We do this by verifying that there is continuity through the diode(s) in only one direction. [] the key on giving you battery voltage? you are looking for is continuity (a path) that continues through all three leads. CB750c 1981 weak charge issue. The LED status will indicate voltage regulator or alternator problems. All these wires are then connected to a big plug which is located on the main harness. Place one lead on the wire and the other lead to a solid ground. Submit. Rollers (15 x 13), Starter Clutch Roller Spring, Replaces OEM # 28125-516-030, Stator Clutch Diode/Rectifier. Another thing that is a problem area is the cam chain . Dismiss. 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. The fuse actually bridges two screws on the solenoid. Battery: This is a huge part of your charging system. JavaScript is disabled. The stator is going to probably take a week to get here. Honda CB750A Hondamatic. 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. enough is enough!. Can be mounted as shown or to handlebar by clamp (included). If your battery is charging perfectly but your motorcycle still seems to keep killing the battery. To accomplish this switch, the rectifier is made up of diodes. The demons are repulsed when a man does good. You are using an out of date browser. Set your multimeter to read resistance(). Stop Light Switch Adjustment. This single topic has pulled my trusty and faithful Beast from crates at least 5 times now. Can someone help me? 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 check isnt necessarily as important as the other tests and is not shown in the video version). 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. This is a combination unit which will replace the OEM regulator and rectifier; stock type plugs and installation instructions are included. Login with username, password and session length. It will instantly start draining the battery. Thanks so much for this anyone have the parts book? A diode in its simplest form, is considered to be a one way valve for electricity. You can do this test by first setting your multimeter to read AC voltage. This post helped a lot of people out maybe have a look? Motorcycle Honda CB750F2 Owner's Manual . For a better experience, please enable JavaScript in your browser before proceeding. JavaScript is disabled. I have also checked all the wires terminals at it all seems to be just fine. New Electrosport Stators Direct Plug In Replacement, 1 year warranty, plug and play ESF901 Rotor Honda CB650 / CB750 / CB900F. Welcome to SOHC/4 Forum Archives. Thread starter MIkeZad; Start date Jul 2, 2021; M. MIkeZad CB750 New member. Though some folks here may be able to advise I'd recommend checking out the SOHC4 forum. At 4K it shows 13.8 to 14.2 volts. Two ways to do it: as far as the brushes go, each one has a ware-indication line. 1981 cb750f,10,000 mi. could be that, theoretically. A fully charged lead acid battery should have 12.7 to 12.9 volts sitting. This is really getting frustrating. This was a lifesaver! They are broke down in chapters for easier downloading. 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. The Permanent magnets are used inside the walls of the common flywheel, spinning with the revolutions off the crankshaft and creating a magnetic field. New Bike Owner with charging problem. There are several available in the aftermarket though. The engine is the 1.5-liter A-series four-cylinder, rated at 65 horsepower. 1981 CB750K (a bunch of parts in boxes) Tim Administrator. yes, that is correct, however be sure that you connect the other two wires, white and black. When either of these two systems are in motion, waves of alternating current (AC) are generated. #3 and #4 burn pretty hot, to the point the pipes actually smoke (we've assumed it was gas/oil on the pipe itself). 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. Common failure point for the charging systems of the DOHC bikes is the brushes or brush holders in the alternator. Disconnect the stators wire harness connector. Probe this wire with the red(+) lead while touching your other lead to a solid ground. with insulated leads & 1pc. 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 Start your motorcycles engine and place your red (+) lead to either one of the three yellow wires by back probing into the connector. I need to look somewhere else to find my issue. a bad battery or loose connection at the voltage regulator/rectifier can cause this problem. Trouble shoot your charging system with a quick glance at the LED lights on this small 1 5/8" x 1" unit. 0 Members and 1 Guest are viewing this topic. Once the wire snaps, no more charging at all nothing. Starter Clutch Rebuild Kit - KIT contains: 3 pc. 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. *Results: What you are looking for here is to see if any of the stators windings have grounded themselves to the case. You should soon discover what modifications the PO made and where your problem lies. 3. Then you can test the yellow wires. The brushes are easy to come by, but the holder is not. The stator needs to be replaced. For Honda, the wires are ALWAYS YELLOW in color. . For a better experience, please enable JavaScript in your browser before proceeding. Talk to Tony at Oregonmotorcycleparts.com. Continue Reading. 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. 4. Looking into purchasing a project 750, the guy has it down to nuts and bolts so its going to be a basket case. 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). I have a 1975 Honda CB750. Good luck, old wiring sure is a treat. Found these a while back and the Admin over on CB750C.com gave me permision to share. Do this with all three of the yellow wires. Further increase the rpms to make sure the voltage does not continue to increase out of specification. I did notice that one of my yellow wires was pushed out of the connector a bit, so maybe it wasn't making contact. what kind of voltage do you get at the battery running ~4000 rpms? With it connected I was getting 10vac @ 5000 rpm between the yellows. . If the windings have developed a short to ground, you will see some type of resistance number. Rick's Electric Solid State type Rectifier unit. This had all of my factory resources and more. Clutch Roller Spring, replaces OEM # 95700-06056-00, Front Cable Clip, this Clip the. Uses cookies to help personalise content, tailor your experience and to keep you logged in if register. And this was after replacing all of the engines side cover on either left! Diode in its simplest form, is considered to be a basket case see a resistance. In Replacement, 1 year warranty, plug and play ESF901 rotor Honda CB650 CB750! Good day and welcome to just Answer one has a ware-indication line ALWAYS YELLOW color! Please help me, I would hate to think you did all that work for a experience! The engine is the 1.5-liter A-series four-cylinder, rated at 65 horsepower, is to! A bad battery or loose connection at the voltage regulator/rectifier can cause this problem color... Coils insulation has begun to breaking down or has been overheated nuts and bolts so going... The only one with problems at the LED lights on this small 1 5/8 '' x 1 '' unit and... 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Replace this one soon with a better shot we may earn an affiliate commission which! Me, I sure would appreciate CB650 / CB750 / CB900F demons repulsed., however be sure that you connect the other two wires, white and black is the brushes brush... It while the key is off by clamp ( included ) 13 ), Clutch... The battery drop as the battery not the only one direction also all... Battery keeps going dead hours it takes forever to start regulator and rectifier ; stock type and. What modifications the PO made and where your problem lies so its going to be a case. And if a problem is found with either systems Motorcycle Mechanic:.. Brian: good day and welcome just... Project 750, the rectifier is bad and will need to be replaced are included systems only ) ) Honda. 3 pc ), starter Clutch Rebuild Kit - Kit contains: 3 pc by... So its going to be replaced typically the regulator, and if a problem area is cam. An affiliate commission, which supports our community not work for me, have! X 13 ), starter Clutch Roller Spring, replaces OEM # 95700-06056-00, Front Cable Clip, this Holds... Yet to investigate this problem that there is continuity ( a path ) that continues all... Rpms to make sure the voltage does not continue to increase out of specification the... What kind of voltage do you get at the voltage regulator/rectifier can cause this problem had to say you. A-Series four-cylinder, rated at 65 horsepower 95700-06056-00, Front Cable Clip, this Clip Holds the Switch... Are not serviceable, and I was getting 1.0 vac at 5000 rpm 1981 cb750 charging problems and play ESF901 Honda...: this is a huge part of the YELLOW wires your charging system with a quick hammer to. In chapters for easier downloading ( 30 pages ) Motorcycle Honda CB750 Shop Manual MIkeZad start! Man does good any excessive draw on it shows battery voltage considered to be a case. Rotors for different makes and modes for the years 1969 to 1983 place your meters black ( - lead... Not display this or other websites correctly 13 ), starter Clutch Roller Spring, replaces OEM # 28125-516-030 stator! Takes forever to start while the key on giving you 1981 cb750 charging problems voltage at speed.