My CB650 project...

[gsdapollo]

Hey everyone,
Here is my 1983 CB650 SC Nighthawk project. I bought the bike for about 600 bucks almost 2 years ago and was going to sell it, till I decided to make a project out of it. Mechanically the bike is pretty sound minus needing new brakes, minor electrical work, and some work on the motor which runs great, but not perfect. So far, all I have really done to the bike is pull all the body panels off; the bike is already about 25 - 30 pounds lighter and I still have more to pull off. I puchased a headlight from a 72 CB750 Super Sport, but I still need to get some mounts because im shaving off the current ones, they are horrible. I also added some Clubmans which is where my first problem lies. Now that I have my throttle mounted on the clubmans, the throttle does not rotate very easily and will not return freely, it just sticks. I've spent the past couple days messing around with the throttle cables to see if I could reposition them so that the throttle would move freely, but to no avail. It seems like slack in the cables is causing friction somewhere. Shortening the cables would seem obvious but they have those round metal studs at both ends and I dont know if I can put them back on after cutting the cable. This is my first project so Im coming across these issues as I go If anyone has any suggestions, please let me know. Thanks.

 

[johnson_steve]

Hello and welcome. I used bicycle brake cables for my throttle and clutch cables. any bike shop should be able to make them up for you in any length and the ends should fit right in your carbs and throttle. I also got the universal headlight ears from Z1 (same ones they have at mikesxs) they look great clamp on to any size forks and cost about $25.

 

[JRK5892]

steve that is a killer tip man!!! Gsdapollo, post some pics man!

 

[johnson_steve]

steve that is a killer tip man!!! Gsdapollo, post some pics man!

I know, right?

I wish I could take credit for it, but I did it after seeing it posted here by another member. I'd like to give credit to who gave me the idea, but I don't remember and the search function on this site sucks ass. I went from a duel cable stock throttle with the start/kill switches to a single cable motion pro racing throttle (offroad use only shh!) and got the cable for $5 at Wheel and sprocket.

 

[BigBSBusa]

Yeah, let's see that bike. Looks like anothr $50 mod from Steve.

 

[gsdapollo]

Finally got around to getting the pics up on photobucket, so here ya go. Ill have to look into the single cable swap, I kinda want to replace the grips anyways so that might give me a reason to replace the whole grip assembly. Ill spend the next week looking into it and see what I can find. Thanks for the advice!!

 

[hillsy]

I used bicycle brake cables for my throttle and clutch cables.

I've used them for throttle / choke cables, but they're too thin for clutch cables

It's a good tip, though - I made up a new set of cables for a PW50 from bicycle stuff for a fraction of the cost of OEM

 

[gsdapollo]

I've got hydraulic brakes and clutch so I dont have to worry about making new cables for those ;D. Just the throttle thats giving me issues. If I go to a single line for the throttle, do I have to change out the little flywheel (whatever its called) that the cables attach to for one that holds only one cable?

 

[johnson_steve]

Too thin for a clutch cable? it's thinner then stock yes, but should I be worried? maybe I should put the stock one back on. that is the one cable I really don't want to brake while I'm ridding. I figured that aircraft cable has a very high tensile strength and should be fine, but I didn't crunch any numbers it was just a guess. I can move the clutch arm with my fingers, how much stress can the cable be under?

No your 2 cable throttle will work just fine with only the 'pull' cable. I ran that way for a while. The motionpro throttle I got was only $25 and it looks so much cleaner then stock. It has no kill switch or start button; it's just the throttle.

 

[hillsy]

Too thin for a clutch cable? it's thinner then stock yes, but should I be worried? maybe I should put the stock one back on. [size=10pt]that is the one cable I really don't want to brake while I'm ridding. [/size]

There's your answer. Clutch cables are that thick because you don't want them to break (and they still do!). Bicycle cable for your clutch will let you down sooner rather than later - and you can bet it will be miles from home too... :'(

 

[johnson_steve]

looks like I'll be putting the stock one back on then. thanks for the warning.

 

[F1R3ST0RM]

im stoked to see how this ends up. I just got a 86 Nighthawk and havent seen many that are done well. I will keep an eye on this for inspiration!

 

[Fort Worth Realtor]

The bike looks much better already with the different handlebars and without that square headlight. I just bought an 84 Nighthawk 650 and have already removed all of that stuff, too. I am waiting on the new handlebars, grips, headlight, and mounts to arrive. I also am shedding that terrible square plastic gauge cluster.

Do you have any updates on this project ?

 

[gsdapollo]

The bike looks much better already with the different handlebars and without that square headlight. I just bought an 84 Nighthawk 650 and have already removed all of that stuff, too. I am waiting on the new handlebars, grips, headlight, and mounts to arrive. I also am shedding that terrible square plastic gauge cluster.

Do you have any updates on this project ?

Hey bud, Im glad to finally see some nighthawk owners going this route (i personally havent seen any). Unfortunately life has gotten in the way of this project seeing as I have just moved back to Cleveland and am currently in the process of starting up a company, but if everything goes well I should have the time and finances to continue working on her by next spring. Regarding my plans for the bike, well I purchased a cb750 round headlight so I just need some new brackets to mount it. I will also be removing that gauge cluster and will be placing a Koso digital speedometer and a Koso analog tach in its place. I will place the links below so you can see what they look like. I am also toying with the idea of putting a cb550 dummy light bracket in there as well but I kinda think it places the gauges too far apart and makes them look kinda dorky so Ill probably pass on it, just an idea though. I may leave the pegs where they are because it makes the bike really comfortable. Plus I would have to probably cut off a big portion of the exhaust pipes seeing that the passenger pegs are too high up and far back for me, and anyways I like the way the stock exhaust pipes look, they just look much better when you take off all the rear body cladding with way they flow upwards with the slight slash cut at the end. The biggest change I will make to the bike though is the rear frame where it makes the bend just before the passenger part of the seat begins. I want to cut the frame off right at the point, then have a new bar welded on that runs up underneath the seat (the bottom of the seat pan has a nice little groove on each side that would allow a pipe to fit perfectly allowing you to keep to the two passenger seat while hiding the frame). Then once that is done, I will come up with a rear lighting scheme, but I havent decided how Im going to do that yet. Im thinking either two LED red lights hangin down from each end of the new frame rails with the license plate in the middle or something else. I also havent decided on a color scheme yet. I go back and forth with that almost every week. But I have time Anyways, keep me updated on your project man. Ill put some more pics up because I have since put the airbox back on along with the side trims. Oh, one thing about the clubmans (if thats what your putting on), since my throttle has both two cables, when I put the clubmans on the cables were much to long and my throttle wouldnt open easily and would not close at all. So I removed the return cable altogether and threw it in the trash. Then I took a dremel and lopped off about half of the half inch metal tab the other cable sits on when attached to the carb. Now it works perfectly. If you run into that problem let me know and Ill take some pics of what I did. Also, I will have to weld in some stops to prevent the handle bars from smacking the tank. The biggest problem with that is the starter button can be activated when it hits the tank. Just little things I never thought about when I did that. Anyways, let me know how yours goes man. Take care.




KOSO Digital Speedo
Page 5, second one down (DL-02S SPEEDOMETER)

KOSO Analog Tach
Page 10, either of the first two (GP STYLE TACHOMETER WITH WATER TEMPERATURE)

http://www.kosonorthamerica.com/

 

[Fort Worth Realtor]

I was actually going to look at an 82 Yamaha Virago on a Saturday morning that I found listed on craigslist for 1000. I called the guy on my way and he tried to pull the old switcharoo and tell me he had a guy coming on wednesday that had agreed to pay 1450 for it. He asked if I could match it. I told him I wasnt interested in bidding against an invisible bidder and to call me if it fell through. My girlfriend realized I was a little irritated and invited me to go with her to get some drinks at the convenience store up from her house. I went and saw this 84 Nighthawk parked on the corner with a For Sale sign on it.

I looked at it and a couple of days later called the Seller to come see it again. I rode it around for a while and it runs great. It fires right up and runs strong every time. Shifts through all the gears smoothly. He was asking a thousand for it and I offered him 900 cash. He agreed.

Some things wrong with it when I got it

- cosmetically the bike looked ok for a 25 year old bike but had a few coats of paint on it. Currently silver but at one point it was red, and I think gold. Whoever painted the body work and engine wasnt very skilled or careful and there is still red overspray visible in a lot of places. The engine was even red at one point (haha) but is now painted high heat black on top. It is peeling in a lot of spots.
- big dorky mirrors and handlebars
- Speedometer doesnt work and neither does the odometer. It shows 14k but who really knows ?
- gas gauge doesnt work
- carbs have some exterior varnishing and need to be cleaned
- It looks like some of the coating is peeling off the inside of the gas tank
- lots of cheap plastic chrome accessories. (turn signals and bar grips)

I am just getting started on this project and am pretty excited about it. I have some boxes of parts showing up tomorrow and am like a kid at Christmas. I love this site. It's a treasurebox of good info. I hope you dont mind answering some questions because I'm sure I will have a few. ;D

 

[gsdapollo]

Thats great man, ya just let me know if you have any questions and make sure to post pics during the process so I can see how its going. GOOD LUCK AND HAVE FUN!!

 

[Fort Worth Realtor]

Alright gsd.....I have the headlight installed and the new mounting brackets. I also have the new bars mocked up. I love the way they look but I am running into the same problem you had with the cable length. Please share what you did to get yours installed correctly. When you removed the return line there were no issues ?

Thanks,

FWR

 

[gsdapollo]

Ha, ok well Ill have to take pics which hopefully I can get good ones without having to take the carbs off, but Ill see what I can do. But basically, if you are looking at the carbs from the throttle side of the bike, the two throttle cables attach to a small rotating assembly located right in between carbs 2 and 3 (in the middle). If you twist the throttle youll notice one cable pulls, and when you let go the other cable pulls the throttle back. First I removed the return cable which, if I remember correctly, is the one located at the bottom of that rotating assembly on the carb, disconnected it from the throttle and pitched it. That still didnt correct the problem with friction. Unfortunately I was never very sober when working on this problem cause it was a little pain in the ass to figure out where the friction inside the cable sleeve was coming from, but I believe the friction from the second cable was coming from the small metal tube that extends out of the throttle housing. Once I moved that around and adjusted it, the friction problem went away, but that revealed a third problem, the cable was about a 1/4 inch too long. Since thats too small a discrepancy to have to measure out and have a new cable made (plus there is a good chance it still wont fit correctly becuase of bends in the old cable distorting an accurate measurement and the new cable stretching over time), I just borrowed a dremel from my buddy, removed the carbs and put them on a bench, then if you look at where that cable attaches on the rotating assembly (which is the top part), youll notice that the cable basically sits between two tabs, a lower tab that sits on one side, and an upper tab that sits on the other side. Before I took the carbs off though, I measured exactly how far down the lower tab the cable sat when the throttle is fully disengaged (remember to set the hand control exactly on the handlebar where you want it to sit so you can get the most accurate measurement). After I did that for about 30 minutes, I pulled the carbs off and cut about half of the lower tab off, and moved both nuts so that they tightened on the very bottom as opposed to one on the bottom of the tab and one in between the bottom of the cable and the top of the bottom tab (if that makes any sense). After that it worked perfectly, but to be honest it took me about a month to get that all worked out. Hopefully it wont take you that long, but just make sure you get rid of any friction in the cables and that the throttle pulls and returns with no hesitation whatsoever before you do any cutting. Good luck, let me know how it goes and if you have anymore questions. Ill try and get some pics.

 

[boingk]

Sounds like you're definitely putting some effort in there guys! Never heard of a dual cable throttle around here, is it a peculiarity on older bikes or legislation for you guys?

Anywho, I personally wouldn't worry about the longevity of the clutch cable mod. Use some good lanolin grease on the bicycle cable and it'll be fine; hell, old engine oil would be better than nothing. As for 'stranding' you...I don't quite see how it'd manage to do that. It happened to me on the wrong end of a mountain pass and I made it home with the biggest grin on my face ever! I lived with no clutch for the next few hundred miles (a legit replacement took ages to come in) and didn't really mind; you just look like a bit of a fool when you're waddle-starting away from the traffic lights haha.

Cheers - boingk

 

[gsdapollo]

Sounds like you're definitely putting some effort in there guys! Never heard of a dual cable throttle around here, is it a peculiarity on older bikes or legislation for you guys?

Well mine as an 83' and his is an 85' so they are probably younger than most of the bikes on here, and they are both Nighthawks so I know they all used dual cables. Im not sure if its common these days though...