- Free and easy way to LIFT your Nighthawk 750 for maintenance
- Carburetor Tutorials (Adobe Acrobat format)
- Carburetor Basics
- Carb Issues Explained
- Adjusting Float Height
- Backfiring Thru Carbs
- Fuel Mixture Screw Adjustment
- The Darn Thing Won't Start
- Carb Cleaning 101
- Carb Cleaning 102
- Jetting Recommendations
- Carb Maintenance and Synchronization
- Carburetor Synchronization
- Balancing Carburetors
- Carburetor Tuning Guidelines
- Carburetor Theory and Tuning (part 1)
- Carburetor Theory and Tuning (part 2)
- Carburetor Theory and Tuning (part 3)
- Carburetor Theory and Tuning (part 4)
- High RPM Engine Carburetor Tuning
- Low RPM Engine Carburetor Tuning
- Carb Tuning Illustrated
- Tuning the Slide-Type Motorcycle Carburetor
- Bad Gas
- Motor Oil (Which oil is best??)
- Motorcycle Oil FIlter cross-reference chart
- If I buy a Nighthawk 650 what can I expect in terms of maintenance?
Other than that, the only known issue that might be worth reporting is that the cam chain tensioner spring tends to lose some of its tension, allowing some cam chain noise after a while. I don't know anyone who's actually had one come apart, but I guess it can get pretty irritating. My 650's got around 23,000 on it with no issues (and it was really abused before I got it, for the first 11k).
Grand Blanc, MI
- Motorcyle Gas Tank Repair and Restoration
- Carburator Theory and Tuning
- Malfunctioning Neutral Light on Nighthawk 650
Note: The following question and response was taken from a Honda Nighthawk discussion group. It was a reply to someone desiring repair help on a Nighthawk 650.
I just purchased a 1983 CB650SC Nighthawk. I like the bike, but not its neutral indicator light. Not only does the light come on when the bike is shifted into neutral, but it also comes on when the clutch is engaged in any gear! Quite maddening! How can I get the indicator to come on only when I shift into neutral?
Rider in Boise, Idaho
Just last week we just solved this exact problem on someone else's NH. The cause is either the diode (Honda calls it a silicon rectifier) or the wires that go to it. You will probably need to replace the diode, which is a small black box that plugs into a two-wire plug beneath the seat / tank junction on the right side, or inside the right side cover. You will need a continuity tester, such as a VOM.
If you have insights and experience on repair and maintenance issues that would benefit other Nighthawk owners, please join my Nighthawk Lovers email group and share with all of us, or shoot me a note here! Paul
2002 Nighthawk 750
Taking off the reservoir cover...be careful the screws have a tendency to stick. Get the right size phillips screwdriver. If you don't have any anti-seize compound, get some. Motorcycles are famous for siezed fasteners. Steel screws in aluminum threads mean seized (dissimilar metals make a battery and electrons flow causing oxidation.)
Checking brake fluid and replacing it are two different things. Brake fluid MUST be replaced regularly (I replace all the fluids brake/clutch once a year). Brake fluid absorbs moisture from the air and gets contaminated. It causes rust in the calipers and that is what causes the sticking and hard-to-press brakes.
The way I do my replacement of fluid is:
1) Cover the tank with plastic and then a cloth. Take a look at your front fender. It may be prone to getting a drip.
2) Remove the brake (or clutch) reservoir
3) With your Mighty Vac suck the reservoir ALMOST dry
4) Fill with fresh brake fluid
5) Remove dust cover from caliper bleed screw
6) Place a box-end wrench on screw (6mm or 8mm)
7) Place Mighty Vac hose on bleed screw end with adapters (if necessary)
8) Pull a vacuum with the Mighty Vac
9) Slowly loosen the bleed screw until brake fluid starts flowing
10) Keep the vacuum going and watch the reservoir
11) When the reservoir gets almost empty, shut the bleed screw off and add more fluid to the reservoir
12) Keep doing that until the fluid looks as clear as what went into the reservoir
13) Resume your Mighty Vac removal (steps 8 thru 11)
14) I would do this a couple of times and then see if the procedure has helped. It may take a couple of times but the problems should start going away if it is not completely jammed.
My Nighthawk had about 9000 miles on it when I got it about 8 years ago. The front brakes felt strange when I got it. I did basically what I described above. Brake fluid came out originally looking like Coca-Cola instead of water. I replaced the fluid 6 months later and it was a little dark but much better. I replaced it again 6 months and it was barely dark. I have been changing once a year when cold crappy weather is here. About 3 years ago I discovered the Valvoline synthetic and now the fluid looks the same (I pull 3 reservoirs for each caliper to make sure). Today my Nighthawk as 48,000 miles on it and the brakes are just fine.
Contributed by Ben Kirk
[PA] '85 CB700SC Omaha, NE USA
(Written by P. Allen and taken from an online discussion group)
- [Further note on Cam Chain Tensioner: The cam chain tensioner on the '83-'85 650 is not manually adjustable. It's spring-loaded and either the spring can lose tension or the slipper can wear out. Repair involves replacement of the offending part and requires removal of the valve covers. The sound of a loose cam chain, as I've recently been told, occurs at lower rpm and is most noticeable when the throttle is snapped shut. Sounds like ball bearings being rolled around in a can. Additional Tip from Dave, taken from Honda Nighthawk email group.]
One day my headlight gave up the ghost out of the blue. Nothing else was malfunctioning. After checking all wiring (as much as possible) and of course the bulb itself, I discovered the problem within the right handle bar "starter" housing. When you push the starter button the headlight is supposed to dim for that moment while the engine is cranking. In the housing is a soldered wire that had come loose. After soldering it back, the headlight worked like new again. I didn't even have to take it off the handlebar! Hope this helps for some other person with sudden "light loss."Maintenance Tip sent to me from John Vanveen, St. Albert, Canada Here's a great HOW-TO site for those willing to tackle tire changing on your motorcycle. Maintenance Tip taken from the Honda Nighthawk email group on Yahoogroups
#1 - Online shopping -
For OEM and aftermerket parts. I highly reccommend http://www.bikebandit.com/ simple easy to use web page, find the smallest parts you need. They have excellent prices and ship very safely/quickly. I have also had excellent luck on eBay.
#2 - Rust -
I have an older friend who has been into boats for 50+ years. We all know what saltwater can do to metal, especially chrome....hmmm maybe those boats guys know some things us bike guys can benefit from, eh? I have been doing rust repairs since.. well.. since I got my first car "laugh with me, not at me." Anyway rust is like a disease. I have found there are 3 kinds of rust: surface, pitted, and complete.
Surface rust is basically tarnish. The metal is still complete and smooth, just hidden under an oxidized layer. This is basically what boats get constantly. I was introduced to a product called "Nevr-Dull" available at any marine store, or ACE hardware. This stuff is absolute magic. You need only a rag and a can of this. It comes as cotton soaked in...um..the magic stuff.. it takes some elbow grease you gotta work a small section at a time. But this stuff WILL amaze you.. Even border-line pitted metal will become almost new with this stuff. Its about 5 bucks for a can and you can do your whole bike easily. Leaves a super protective coat on the fresh metal. Great for any unpainted metal. Especially Chrome/ polished.
Pitted rust is where you can still see the original metal but the rust has eaten into it. My advise, same as the other guy who advised using a wire brush. You can get all shapes and sizes to fit your needs. I use a 2 inch wheel in a small 9V drill. It worked extremely well. Note: by using an abrasive, chrome will not look the same, it will have a different shine, unless you really spend time downgrading the abrasive and polishing. Sometimes you can do a combination of Nevr-Dull and the abrasive method, so as to do as little wire brushing as possible. Also when done use the Nevr-Dull to coat the newly exposed metal or it'll flash rust in a few days. Great for any unpainted metal.
Complete rust where the metal flakes off in your hand is obviously the worst kind. **Usually requires cutting out effected area, then either fiber-glassing or welding new metal as a replacement. I have done both. Either is a tedious and frustrating job. Both are costly too, depending on how big the area is. If you can do the fiberglass, you will have better results as a DIYer (do-it-yourselfer) and small fixes are easy and cheap especially dealing with plastic fairings. Welding is always my last choice. Its not easy to do, and a shop will charge a bunch as most bikes have many aluminum parts which are very difficult to weld.
**Even if the metal is flaking off, sometimes if there is enough integrity left in the metal, and if its not a working part, you can buy Naval Jelly (Home Depot, Auto Parts) a pink, snot-like, acid that dissolves rust. It works pretty good if you are going to paint over it. #3 - for those of you with the newer nighthawk 750s, (91+) check out this page: - http://www.nighthawk750.com/index.shtml under MODIFICATIONS. I totally recommend the carb needle washer mod and the Tim Hodge mod. They are easy to do and cost less than 20 bucks. Both have significantly improved the overall performance of my bike. I can start the bike with the choke and after 20 seconds be on my way without that notorious "Honda hesitation," or 5 minute warm-up. The bike actually gets better gas mileage now. 165 before reserve. The above tips were sent to me by Steven Peto from New Jersey, owner of a 1993 Nighthawk 750.-->
If you have insights and experience on repair and maintenance issues that would benefit other Nighthawk owners, please join my Nighthawk Lovers email group and share with all of us, or shoot me a note here!