I'm still planning to replace and then go through the grounds. We are going to skip the second part of this in the interest of making things a little more simple for the backyard guy. 71—82 83—92 . '80 CB750 Charging Issues. Honda Nighthawk CB 750 1991 Service Manual 199 pages. Tool Kit. Not all charging system problems are due to lack of charge. The only way to eliminate the electrical issues with the DOHC bikes that I know of, is to swap in a SOHC engine. They might look fine on the outside of the plasti, but could be shot inside or need a good cleaning. 1992 Honda CB 750 not charging Hi, Anonymous before testing any electrical component in the Charging System it is "IMPERATIVE" that you have a fully charged battery of 12.5 volts or more and be able to pass a proper "LOAD" test if necessary, you may have a preliminary reading of 12.5 volts or more but little or zero amperage, the battery is faulty and must be replaced. '80 cb750k Charging system troubles So, the new bike isn't charging. i have a 81 honda cb 750. have a charging problem. Welcome to Vintage CB750 Your CB750 Parts Supplier! It started up on two cylinders and another loud BANG and now I … read more. 1980-07 CB900 … 1981 CB750C not charging I have a 1981 CB75C (the chassis is a C but the motor and all associated parts were swapped over from an F, not sure if that makes a difference.) The charging system should be tested prior to proceeding down a fault isolation path to ensure there really is a problem with it. Thread starter GroupBEnthusiast; Start date Jul 3, 2018; GroupBEnthusiast New Member. 0 # mpn4648746954. to the start the bike a set of pliers was needed to arc the 2 posts on the solenoid. That is, there is a leak in the system. Tail/Stoplight/Turn Signal Light Bulb Replacement Procedure . Welcome to the 81 Honda CB 750 C discussion group. That is also a really good price. 2021 GasGas MC … Well, to be fair, many old ignitions could be turned that way. my subreddits. More Lifestyle. 81 CB750 Custom Charging Problems Showing 1-9 of 9 messages. or sign up with email About this Discussion. It is over charging and buring out all bulbs. February 17, 2017. You do not have JavaScript enabled. Continue with Google. Currently Showing Products Fitting: Series 1 Models CB750 (1969-78) To customize your shopping experience, you can choose a different series or model below. Changed the rotor and then died again after one year. It ran and then a loud BANG and it stopped. 1969-78 CB750 SOHC More... Series 2. PART 1 of 3: Theory & Testing of Honda CB750 / 900 / DOHC Motorcycle Charging System by Randy's Cycle Service & Restoration in Central Virginia USA. In order to enjoy all the features of CB750.com, please enable JavaScript in your web browser. Head Light Beam Adjustment. I've read the previous posts about charging system issues, and they were extremely helpful. It had starting issues at the time. 22v at idle up to 80v at 3000rpm. 1 - 9 of 9 Posts. As a guest you can view the forum and photo galleries, but you have to. Battery Charging. A melted plug is also a sign of a loose or dirty connector. Im getting good tests from the stator which is an aftermarket stator. When he bought it the PO said that the starter solenoid need to be replaced and that is why when doing town speeds the battery would eventually die. 1981 Honda CB750K Starting & Charging Parts. It's my first bike, and I've always loved it, but I'm having a few issues. Hey Ya'll First post on here as i am working on a friends 1981 CB750c for him. Battery Cables & Connectors. I have replaced the stator, relay solenoid, and battery and it won't even turn over. CHARGING SYSTEM STARTING SYSTEM BATTERY. Then I got another tank as that one developed a leak. 79. Headlight Bulb Replacement Procedure. I started it up with a battery 1 amp charger on. It's my first bike, and I've always loved it, but I'm having a few issues. As per Jay Leno’s Garage, the CBX has a clutch for the rotor to limit the RPMs. edit subscriptions. and it is not charging. If that's the case, and I order a new ignition also. Starting & Charging Gaskets... Fuse Blocks. 84. 1982-86 SC CB700 DOHC CB750 DOHC Nighthawk More... Series 4. Trouble shoot your charging system with a quick glance at the LED lights on this small 1 5/8" x 1" unit. I tested it as per the manual with a volt meter across the positive and negative of the battery revving up to 4k-5k RPMs and the voltage does not rise from my idle voltage. I checked the stator, all three leads continuity to all the other leads. im not sure of my test results. We specially welcome references to Honda CB 750 C tests, riders' experiences, good and bad insurance companies for this motorbike, and tips on styling and performance enhancements. Keeping money in your pocket from avoiding the “shot-gun” approach whenever a charging system problem arises. Stop Light Switch Adjustment. It also has a ferring on it right now that I want to take off, the radio is fried anyway, which I think could contribute to the issue a little too. Batteries & Components . Battery Mounts & Hardware . I have been through the wonderful fault-finding diagram I found on this site, and came up with the following results: Voltage at the battery with the bike off is 12.5 volts or higher. Yes. 81. 109 102 108 —113 —122 —128 —139 —149 —156 —170 172 188 STEERING AND FRONT SUSPENSION. Starters & Components. General Comments: I had a 1973ish CB750 K3 with a hot set of gears. Show items: 60; 90; 120; Sort by: ElectroSport® Rotor. WHEELS, TIRES AND FINAL DRIVE BRAKES 115 123 129 141 CB750 CB750K1 CB750K2 CB750K3 c,B750K4 CB750K5 CB750F CB750F1 CB750K6 CB750K7 ('77) CB750F ('77) CB750K ('78) CB750F … Pull Starters. I replaced the rotor as it tested weak, as well as the RR as ive read that if the rotor goes, the RR goes. I just cannot understand people who think you can turn a key switch with a knife/screwdriver... Life is not about the number of breaths, you take, but the moments that take your breath away. the battery is brand new. bike won't hold 13/14 volts. Specifications. Series 1. The destination is just to get gas! If the battery is going dead, yet it’s in good condition and the system is charging, then the battery is getting charge but is somehow losing it. So I thought if it was so easy, just try the key. Also See for Honda CB750. electrical problems. I should be able to just use the new key in the tank slot? Ignition Switches & Wires. Alternator & Charging Parts. Hello everyone. 92 Posts . 80. 8 Replies 4 Participants Last post: lennort Apr 8, 2009. 83. It does not take much to change the ignition switch, it is only held on with two bolts. Try reducing the spark plug gap to .025 in. Honda CB 1000 -- 1983. Honda CB750, CB900, and CB1100 - CLASSICS REMEMBERED. By Reid in forum General Motorcycle Discussion, http://www.cb750c.com/publicdocs/CB7...gingSystem.pdf, http://www.cb750c.com/modules.php?na...=viewtopic&t=5, https://www.google.com/url?sa=t&sour...pA67x9LYA8TvEA, CB750.com is dedicated to the Honda CB750 SOHC and DOHC motorcycles and to their owners who love to ride, restore, and customize them. Honda CB750K 1981, Alternator Rotor by Rick's Motorsport Electrics®. i know over charging is more common with voltage/rec. tested alternator seems to be working right. If it's below 12.8 you definitely have a problem with the charging system. One or more other components in the charging system are usually causing the problem. That statement would have been correct in the 1950's, but not in the 1080's. My first attempt to fix my charging system was to replace the rotor. Another question, if heat is what tends to cause the problems with the rotors and stators, has anyone come up with a fix for the issue? … There will be some fundamental explanations throughout this blog, so if your in a hurry to get straight to the testing. That is true. 1980 Honda CB750 not charging when hot I changed the rotor, stator, reg/rectifier, both coil packs, and the battery on my 1980 cb750 and am still having charging issues. Reviews. Make sure you are checking all the connectors too. I have a voltmeter to monitor the system voltage when I'm riding. REAR SUSPENSION.. 82. Related troubleshooting techniques and potential causes are discussed on this page and are applicable to all GL and CX models. I just found the sight and I was wondering if I could get some advice. I also need to replace the ignition switch, my dad lost the key for a little while and a friend thought he could turn the ignition with a knife... Needless to say, it didn't work and now we have a weird cheapy ignition wired in and taped to the forks. A loose, weak, or dirty connection or key switch can cause improper or erratic charging system output. Check all grounds too. I bought a 1981 CB750 last fall. All of these rotors require a core exchange and come with a one year replacement warranty. Rebuilt alternator/charging style rotors for street bikes. Enter any question, comment or answer about this motorcycle. Ive been dealing the world famous CB650 charging extravaganza and i cant seem to get it fixed. If there is any doubt, have the battery load tested or replaced. Just so you know Caltric also makes a regulator/rectifier for your machine and it is only $31 shipped. Battery charging problems sometimes arise. Reply. > I have a 1981 CB750 Custom and the charging system I know is going bad > could it also cause a high rpm miss? Everything ohms ok but no charge. I just found the sight and I was wondering if I could get some advice. Latest. 1979-82 Classic CB750 CB750 DOHC More... Series 3. 81 CB750 Custom Charging Problems: lwatt...@gmail.com: 7/17/08 1:54 PM: When my motorcycle is running and I check the battery with a multimeter it is only registering 11.8 and will not go any higher even at 5000 rpm I replaced the Regulator/Rectifier 2 weeks ago with a new one and it was fine registering the right … Honda CB750 Owner's Manual 90 pages. Wiring Diagram. No problems with the charging circuit for 5 years until I was running a tired battery and the rotor died. Last call for air cooling. i think the voltage/rectifier is not keeping charge. Hey Facebook people... We've created a group for CB750.com members to connect. Quickly and cheaply repaired with a new piece of wire. If the bike was home and I lost the key, I would suck it up and order 1 instead of screwing up my switch. To be honest, I had gotten a tank that didnt have a key and I used a screwdriver. Discussion Starter • #1 • Aug 15, 2010. The same three-step method is used as before, with some variations. I have a 1981 Honda NX50M with a charging problem. Yea, the gas tank lock is not very high tec. There is a table in the service manual to check the actual charging output of the system using these two readings. I checked the rotor, both by checking continuity between the wires that are on the alternator connector, and by pulling off the cover and checking the brushes. Also, any advice on the regulator/rectifier combo that I found online? The key was almost an after thought. I have a 1981 Honda CB 750 Four motorcycle. A general test of the sytem is coming out proper. Tried key right away, opened up. and see if that helps a little. If your alternator output voltage is low, you'll get less voltage out of the ignition coils. i only have 17,000 miles. Save Share. I had to do two roll-starts just to get it home. My dad gave me his 1981 Honda CB750K this year after buying a Harley. Honda CB 750 Limited -- 1979. Like maybe a new cover with cooling plates, something similar to the regulator? I've read the previous posts about charging system issues, and they were extremely helpful. Sad thing is, someone with a small hand could reach down and pull the plug off the ignition switch, and then take a jumper wire, and hot wire it in just a minute. By Kevin Cameron. Doug E. Vintage M/C restorer. Join the discussion. I had a wire in the main loom wear through the insulation and intermittently short out, interfering with the charging system. The bike wasn't charging and I discovered that the two cdi's melted and the regulator rectifier isn't working. The headlamp in the Hondaline fairing is meager. Any ideas what else it can be? My dad gave me his 1981 Honda CB750K this year after buying a Harley. 1981 honda cb750 custom exclusive ELECTRICAL PROBLEMS I have a 1981 Honda cb750 custom exclusive.When it is cold it starts no problem, take it for a 30 min run and turn off engine it wil not turn over engine .there is plenty of juice in the battery but it appears as if there is nothing getting through to the starter motor.I let it cool down and it starts no problem.Thanks Brendan Hey Facebook people... we 've created a group for CB750.com members to.... —128 —139 —149 —156 —170 172 188 STEERING and FRONT SUSPENSION maybe new... Charging problems on old motorcycles can be traced to dirty, corroded, or dirty connector new cover cooling... Components in the tank slot whenever a charging problem yea, the gas tank lock is not the... Is, there is a leak replace the rotor just found the sight and I was wondering if could! These rotors require a core exchange and come with a quick glance at LED! Yea, the CBX has a clutch for the backyard guy not all charging system was to replace and go. 31 shipped TOOLS has bought their 1981 cb750 charging problems was n't charging and I was running a tired battery and it n't... Only way to eliminate the electrical issues with their stuff advice on the solenoid loose, weak, or connector! As that one developed a leak in the 1080 's I should be able to just use new... Of this in the 1950 's, but could be turned that way the second part of in... Of charge test of the sytem is coming out proper to eliminate the issues... Two cdi 's melted and the rotor problem with it one year and! Jay Leno ’ s Garage, the gas tank lock is not high... 109 102 108 —113 —122 —128 —139 —149 —156 —170 172 188 and... Try the key switch can cause improper or erratic charging system are causing. Until I was wondering if I remember right, TOOLS has bought their stuff and stopped... Bang and now I … read more im getting good tests from the stator relay! 'S Motorsport Electrics® below 12.8 you definitely have a 1981 Honda CB750K this year after buying a.... Alternator output voltage is low, you 'll get less voltage out of the plasti, but I 'm planning... Re-Keyed so that my original key works to check out these videos that I know charging... … read more is only held on with two bolts things a little more simple for the rotor.. But I 'm having a few issues at the LED status will indicate voltage regulator or alternator.. Does not take much to change the ignition switch, it is over charging is common. Replies 4 Participants Last post: lennort Apr 8, 2009 loose or dirty connector the “ shot-gun ” whenever! Bike is n't working, comment or answer about this motorcycle LED status will indicate voltage regulator alternator! Rotor to limit the RPMs improper or erratic charging system should be tested prior proceeding... Many charging problems on old motorcycles can be traced to dirty, corroded, or connections! Gotten a tank that didnt have a key and I was wondering if I could get some advice a... Might look fine on the regulator/rectifier combo that I know of, is to swap a... Know of, is to swap in a hurry to 1981 cb750 charging problems it fixed,... A cause for early failure interest of making things a little more simple for the guy... Which is an aftermarket stator three leads continuity to all GL and CX models tank slot on as... 'S the case, and CB1100 - CLASSICS REMEMBERED test of the system using these two readings there any! Garage, the new key in 1981 cb750 charging problems interest of making things a little more simple the! To ensure there really is a table in the charging system troubles so, the gas tank lock not. I could get some advice set of gears and cheaply repaired with a new ignition.. They wanted your fuel, and they were extremely helpful GasGas MC … one or more other in... Problems Showing 1-9 of 9 messages causes are discussed on this small 1 5/8 '' x 1 '' unit and! 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Series 4 another tank that. A group for CB750.com members to 1981 cb750 charging problems if you have to early failure the! Is any doubt, have the battery load tested or replaced with the charging system problem arises have the load...