Author Topic: 1980 Honda CB650 Project | need advice 🙏🙏  (Read 1307 times)

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Offline yard

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1980 Honda CB650 Project | need advice 🙏🙏
« on: September 08, 2023, 09:16:35 PM »
hey guys! i've just gotten my membership in this forum approved (first post!), and i've recently purchased a 1980 CB650 and am planning on doing a complete restoration with the thing and turn it into a cafe/brat-style bike. This is also my very first project bike, so I figured you guys hopefully might be able to give me some guidance on this build.

A few questions I have:

- should I try to do any performance upgrades to the engine (big bore, performance cams, etc.), or would I probably just be better off just cleaning it up and leaving it stock? for context, this is not only my first project but i'm planning on having it be my very first vehicle too; i don't have a drivers license or motorcycle license just yet, but both are on their way.

- i'd like to try and replace the rear wheel's drum brake with a disc brake. would that be a very difficult task? I know I would have to somehow install a master cylinder for the rear wheel too.

- i'm not sure what i should do regarding the carbs and air filters. i've heard that trying to tune pods is a nightmare, so i figure i might just go ahead and buy the oem airbox instead; however, if i do go forward with engine performance mods, would using the stock airbox not provide enough airflow to the engine? if so, what would be a better alternative? 

- what are some vendors that make quality parts for this bike?

that's everything i can think of off the top of my head. thanks in advance!

Offline scunny

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Re: 1980 Honda CB650 Project | need advice 🙏🙏
« Reply #1 on: September 08, 2023, 11:07:59 PM »
For a first build.
Keep the air box
Leave the rear drum brake
As the red headed step child of the sohc community, there aren't a lot of performance parts available without spending a lot of money.
Get it running nicely, if you want to improve it, look into the suspension.
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Offline yard

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Re: 1980 Honda CB650 Project | need advice 🙏🙏
« Reply #2 on: September 08, 2023, 11:57:40 PM »
thanks! i'm also planning on completely redoing the electrical - partly because the old electrical was in pretty bad condition, and partly because i just want to learn the basics of automotive electrical systems. i was wondering if you might have any tips for doing this?

Offline fizzlebottom

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Re: 1980 Honda CB650 Project | need advice 🙏🙏
« Reply #3 on: September 09, 2023, 09:05:12 AM »
Parroting what scunny said. Leaves it all alone. There are few, if any, performance parts available for the 650s. Learn your maintenance, get a service manual, stock up on some tools, and get riding.

Upgrades I can suggest are some quality shocks, brake pads, and decent tires.
1982 CB650SC Nighthawk

Offline yard

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Re: 1980 Honda CB650 Project | need advice 🙏🙏
« Reply #4 on: September 09, 2023, 09:31:14 AM »
thanks for the advice - i'll do that. now that i think about it, trying to find quality performance parts that don't cost me an arm and a leg for this thing online has been impossible 😭 advice is much appreciated tho, saved me a lot of trouble. thanks again!

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Re: 1980 Honda CB650 Project | need advice 🙏🙏
« Reply #5 on: September 09, 2023, 11:16:53 AM »
Some motor parts are impossible to find on the 650 and others are very difficult to find. Honda OEM head gaskets are very hard to find. Timing chain Tensioner slider is no longer made. There simply isn't enough demand to make it worthwhile for aftermarket to invest in making the parts and Honda isn't going to do it.
So, if it runs well, then run it.
Ignitors on the cdi ignition are no longer made and tough to find good used ones.
Work on improving handling with replacement springs in front forks and gold emulator valves with good rear shocks. Work on your brakes to make them perform well, then fit good sticky rubber and learn to ride the wheels off it...
That's my $0.05 of advice
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Offline jgger

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Re: 1980 Honda CB650 Project | need advice 🙏🙏
« Reply #6 on: September 09, 2023, 11:20:27 AM »
This does not mean you can't spruce it up and have a sweet looking ride. Do it a little bit at a time or as a 1st bike you might end up selling it in boxes. Good luck and keep us informed about your progress.
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Offline fizzlebottom

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Re: 1980 Honda CB650 Project | need advice 🙏🙏
« Reply #7 on: September 09, 2023, 12:40:33 PM »
Some motor parts are impossible to find on the 650 and others are very difficult to find. Honda OEM head gaskets are very hard to find. Timing chain Tensioner slider is no longer made. There simply isn't enough demand to make it worthwhile for aftermarket to invest in making the parts and Honda isn't going to do it.
So, if it runs well, then run it.
Ignitors on the cdi ignition are no longer made and tough to find good used ones.
Work on improving handling with replacement springs in front forks and gold emulator valves with good rear shocks. Work on your brakes to make them perform well, then fit good sticky rubber and learn to ride the wheels off it...
That's my $0.05 of advice

There are plenty of rebuild kits available with serviceable head gaskets. An OEM one is highly preferred, but I think its been mentioned that NE Brand was (is?) an original manufacturer for Honda and I wouldn't have any issues using their gaskets. Athena has also been around long enough that I think they make decent stuff.

The other thing I'll disagree with is the unavailability of ignition modules (CDI, but not CDI). They are actually available from a few sources. They're aftermarket and expensive but as long as they work then they work.

Progressive Suspension makes some great rear shocks and Ripple Rock Racers makes a really nice exhaust system. After that, I'd call it with changes and simply ride.
1982 CB650SC Nighthawk

Offline yard

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Re: 1980 Honda CB650 Project | need advice 🙏🙏
« Reply #8 on: September 09, 2023, 02:21:53 PM »
thanks for the information about the suspension; super helpful, seriously. do you know where i might be able to find the ignition systems? Also, i've decided to take the thing to a vintage repair shop to do the following: get the frame powder coated, the engine cleaned up, polished, and maybe powder coated too, getting the tank repainted, the carbs rejetted, and a new seat upholstered. they're asking for 2500$. Is that a reasonable price? Again, i'm really quite new to this stuff so i don't really have anything to compare the price too. Thank you!

Offline jgger

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Re: 1980 Honda CB650 Project | need advice 🙏🙏
« Reply #9 on: September 09, 2023, 02:52:24 PM »
If you are  rolling/ riding the bike in there it sounds reasonable.  Be advised that you will not get your money back out of it on a sale., IMHO..  But that is old bikes for the most part.

BTW the 650 and some Goldwings share the same spark boxes from what I understand.
"The SOHC4 uses a computer located about 2-3 ft above the seat.  Those sometimes need additional programming." -stolen from  Two Tired

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Offline yard

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Re: 1980 Honda CB650 Project | need advice 🙏🙏
« Reply #10 on: September 09, 2023, 03:03:17 PM »
i'm bringing in the frame, engine, carbs, and tank all dissassembled (although the engine is still attached to the frame). should i request less than asking price?

Offline fizzlebottom

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Re: 1980 Honda CB650 Project | need advice 🙏🙏
« Reply #11 on: September 10, 2023, 12:34:54 AM »
thanks for the information about the suspension; super helpful, seriously. do you know where i might be able to find the ignition systems? Also, i've decided to take the thing to a vintage repair shop to do the following: get the frame powder coated, the engine cleaned up, polished, and maybe powder coated too, getting the tank repainted, the carbs rejetted, and a new seat upholstered. they're asking for 2500$. Is that a reasonable price? Again, i'm really quite new to this stuff so i don't really have anything to compare the price too. Thank you!

You're putting A LOT of money into this, and I'll be honest in saying that even though I love the 650s, I do not think it is worth it.

There's no reason under the sun to rejet the carbs, first. They probably need to be cleaned which will be $400 of that $2500. They'll run great with stock jets when setup properly. The rest is cosmetic stuff you're paying for. I'd hold off on just about everything else except maybe recovering the seat.

I think you need to focus on the basics, like learning how to adjust valves, sync carbs, change your oil & spark plugs, etc. You have no need currently to change your ignition components or go swapping major parts. Just get the bike running nicely first.
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Online newday777

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Re: 1980 Honda CB650 Project | need advice 🙏🙏
« Reply #12 on: September 10, 2023, 01:40:56 AM »
thanks for the information about the suspension; super helpful, seriously. do you know where i might be able to find the ignition systems? Also, i've decided to take the thing to a vintage repair shop to do the following: get the frame powder coated, the engine cleaned up, polished, and maybe powder coated too, getting the tank repainted, the carbs rejetted, and a new seat upholstered. they're asking for 2500$. Is that a reasonable price? Again, i'm really quite new to this stuff so i don't really have anything to compare the price too. Thank you!
Welcome aboard the forum and to the motorcycle industry

Whoa! Slow your jets son. You are jumping too fast and giving too little time in learning before you start dumping your money on something you know so little of.
You say the shop is asking $2,500. Is that for a deposit? Or is that a for the total cost?? Most likely that is just a deposit to get started and much more costs will be added.
Do you have knowledge of others that have gone to this shop, of it being a reputable shop and people running it/working there and keeping to their prices given? A project you have described could likely cost you into lots higher price tags. Do you have deep pockets of lots of money to fund this to be done by a shop?

Have you taken a motorcycle safety course yet to learn the basics of keeping yourself safe on the road? Going fast from the start will most likely get yourself killed or badly mangled for life. I would highly recommend that you get yourself a slow bike, ie a 250 that is running properly to learn to ride on first while you build a bigger bike. Take your time and live.
« Last Edit: September 10, 2023, 01:42:39 AM by newday777 »
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1975 K5 Planet Blue my summer ride, it was a friend's bike I worked with at the Honda shop in 76, lots of fun to be on it again
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1972 Suzuki GT380 I had charge of it for a year in 1973 while my friend was deployed and learned to love street riding....
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New CB750 K5 Planet Blue, demise by ex cousin in law at 9,000 miles...
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Offline calj737

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Re: 1980 Honda CB650 Project | need advice 🙏🙏
« Reply #13 on: September 10, 2023, 04:13:09 AM »
Also, i've decided to take the thing to a vintage repair shop to do the following: get the frame powder coated, the engine cleaned up, polished, and maybe powder coated too, getting the tank repainted, the carbs rejetted, and a new seat upholstered. they're asking for 2500$. Is that a reasonable price?
If you are willing to pay the money to have someone else do the work, then $2,500 is very reasonable. Powder coating a frame is about $300. Repainting a tank is likely to be about $600-$1,000 of that money (depending upon the quality of the work).

You can’t powder coat the motor unless it is completely disassembled to the bare cases (figure $300-$400 to do the disassembly). Powder coating the motor is another $400. Then reassembling the motor is going to be another $300 in labor, plus any and all baskets, seals, and rebuild kits.

None of this accounts for any custom changes or “upgrades”.

The 650 was a bit of a red headed step child in the SOHC (single overhead cam) world. It was more of a cruiser than street sport. The frame is different, the seat is dropped, the bars were more upright. All this makes for more difficult and more involved customization to a “cafe/brat”.

Here’s a bit of advice you haven’t gotten: consider abandoning THIS bike and find a CB 550 model between 1973-1978. There should be plenty out there. Easier to work on, easier to customize, better looking. Heck, I’ve got a 1.5 customized frames sitting in my “get rid of” pile.

There’s frequently folks on here trying to unload parts bikes that would be a better starting point for a first bike, first project.
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"Of all tyrannies, a tyranny sincerely exercised for the good of it's victim may be the most oppressive. It may be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated, but those who torment us for our own good will torment us without end for they do so with the approval of their own conscience." - C.S. Lewis

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Re: 1980 Honda CB650 Project | need advice 🙏🙏
« Reply #14 on: September 10, 2023, 04:57:20 AM »
Good advice from Calj.
Or if the 650 motor is a good runner, drop it into a 550 frame.
Learn to do the work yourself. Otherwise you are always depending on others, not a good combination for old motorcycles unless you have deep pockets and don’t mind long periods of not having a bike since you are waiting on others to find the time or waiting in queue to be worked on…
« Last Edit: September 10, 2023, 04:59:53 AM by RAFster122s »
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Offline yard

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Re: 1980 Honda CB650 Project | need advice 🙏🙏
« Reply #15 on: September 10, 2023, 07:35:51 AM »
I think that I'm going to go ahead and keep going on this project - I already sent in the frame, tank, carbs, and motor to the shop to get polished and cleaned up. I'm only planning on replacing the suspension, the entire electrical system (the lighting & gauges included), the brake pads, and a few other cosmetic things (seat, handlebars, etc.). Other than that, I'm planning on just leaving the thing stock for the most part. Also, I have taken a MSF course - it is required for me to get my motorcyclist permit as I am only 16 - and I have rode in other countries as well.

Also, I'm planning on doing a front fork swap, from the stock one to a CBR600RR fork. I haven't really been able to find good rear shocks for this thing - as you guys said, red headed step child of the SOHC's, so aftermarket is a bit weak. If you guys knew any places to find some solid rear shocks, I'd be super thankful.

For the electrical - I saw Cognito Moto's m-unit, and was wondering if trying to put on a digital control system similar to that might be a useful addition to the thing.

This is definitely a pretty big project for me, but honestly progress so far has been really solid. I'm looking forward to spending the countless hours making this thing my own ;D

Offline MauiK3

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Re: 1980 Honda CB650 Project | need advice 🙏🙏
« Reply #16 on: September 10, 2023, 07:42:59 AM »
Hagon can set you up with shocks I think.
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Offline calj737

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Re: 1980 Honda CB650 Project | need advice 🙏🙏
« Reply #17 on: September 10, 2023, 02:09:24 PM »
The m-Unit is. Good choice, but pay special attention to the need for the CDI module.
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"Of all tyrannies, a tyranny sincerely exercised for the good of it's victim may be the most oppressive. It may be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated, but those who torment us for our own good will torment us without end for they do so with the approval of their own conscience." - C.S. Lewis

Offline fizzlebottom

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Re: 1980 Honda CB650 Project | need advice 🙏🙏
« Reply #18 on: September 10, 2023, 06:04:03 PM »
Hagon can set you up with shocks I think.

I just got a set of shocks from Progressive Suspension and the did me good on a nice 140mi weekend ride.
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