Author Topic: first timer 1980 cb650c  (Read 3616 times)

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Offline lennonG

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first timer 1980 cb650c
« on: March 14, 2016, 11:14:39 PM »
 Hello! just signed up here and have a 1980 honda cb650c i got for 400 bucks..first time working on a motorcycle (prepare for some questions...haha) i guess ill get down to the info i have thus far!

-bike isn't running, it turns over, just won't run
-its got a snapped throttle cable (push and pull already ordered)
-PO said the guy he got it from rebuilt the motor (guessing top end as theres what looks like new gaskets, and 1 joint is rtv only i think, leaking oil)
-carbs need to be cleaned, bike sat outside over winter
-he told me he got a new battery last year, after reading online im slightly worried the charging system is pooched.. time will tell..

my brother in-law is a certified mechanic, who is willing to help me out to get it running if i need help, so im not completely in the dark but i want to do as much as possible on my own.. oh and i have a honda manual ordered, also a clymers..

well, more to come! i already have pictures to post, just need 5 post i guess.. as of right now its sitting in my garage, seat and tank off, awaiting throttle cables! CHEERS!

the day i brought it home


caked with muck


RTV oozin... need to fix this
« Last Edit: March 15, 2016, 01:23:29 PM by Lennon Giesbrecht »

Offline SOHC4 Cafe Racer Fan

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Re: first timer 1980 cb650c
« Reply #1 on: March 15, 2016, 09:26:32 AM »
You do not need to buy a manual.  You can download one here: http://www.sohc4.net/cb650-manuals/

I would suggest downloading it, printing a copy and putting it in a binder for reference.

You will want to go though each system of the bike to get it back into reliable, safe running condition.

You should probably start with cleaning your fuel tank, lines, and carburetors.  The carburetors if sitting with gas in them, will be clogged and need to be ultrasonically cleaned and possibly rebuilt. 

RTV is not a suitable substitute for a gasket.  The material can easily get into the oil and clog oil passageways.  If portions of your engine are deprived from oil, it can lead to serious damage.
1975 CB550K1 "Blue" Stockish Restomod (http://forums.sohc4.net/index.php?topic=135005.0)
1975 CB550F1 frame/CB650 engine hybrid "The Hot Mess" (http://forums.sohc4.net/index.php/topic,150220.0.html)
2008 Triumph Thruxton (http://forums.sohc4.net/index.php/topic,190956.0.html)
2014 MV Agusta Brutale Dragster 800
2015 Yamaha FZ-09 (http://forums.sohc4.net/index.php/topic,186861.0.html)

"There are some things nobody needs in this world, and a bright-red, hunch-back, warp-speed 900cc cafe racer is one of them — but I want one anyway, and on some days I actually believe I need one.... Being shot out of a cannon will always be better than being squeezed out of a tube. That is why God made fast motorcycles, Bubba." Hunter S. Thompson, Song of the Sausage Creature, Cycle World, March 1995.  (http://www.latexnet.org/~csmith/sausage.html and https://magazine.cycleworld.com/article/1995/3/1/song-of-the-sausage-creature)

Sold/Emeritus
1973 CB750K2 "Bionic Mongrel" (http://forums.sohc4.net/index.php?topic=132734.0) - Sold
1977 CB750K7 "Nine Lives" Restomod (http://forums.sohc4.net/index.php?topic=50490.0) - Sold
2005 RVT1000RR RC51-SP2 "El Diablo" - Sold
2016+ Triumph Thruxton 1200 R (http://forums.sohc4.net/index.php/topic,170198.0.html) - Sold

Offline lennonG

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Re: first timer 1980 cb650c
« Reply #2 on: March 15, 2016, 12:55:56 PM »
thanks for the input! i already tried to download that manual and it says document not found.. i have the version for a 1979 cb650z i believe, from cosky0.tripod.com...

i already have the tank off, going to empty it and clean it. my buddy has a jug of carb cleaner left from doing his kz1000 over winter so he's gonna give me that, and if need be i'll rebuild.

When i began to take the throttle cables off, i figured out my pull cable is the only one broken, pulled it out and found where it goes in at the bars the cables shredded, not sure if there is a nut that hooks up inside the throttle assembly at the bars? if so i'll have to take that apart and retrieve it. I'm going to replace both push and pull anyway (when they get here....)

I agree RTV isn't gonna cut it in place of a gasket, i'll have to give it all a once over to make sure its still okay...  this project is gonna be a lot of learning for me, already enjoying it though!
« Last Edit: March 15, 2016, 01:35:58 PM by lennonG »

Offline SOHC4 Cafe Racer Fan

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Re: first timer 1980 cb650c
« Reply #3 on: March 15, 2016, 01:51:53 PM »
thanks for the input! i already tried to download that manual and it says document not found.. i have the version for a 1979 cb650z i believe, from cosky0.tripod.com...

Send me a PM with your email address. I will email you the manual tonight from my home computer.
1975 CB550K1 "Blue" Stockish Restomod (http://forums.sohc4.net/index.php?topic=135005.0)
1975 CB550F1 frame/CB650 engine hybrid "The Hot Mess" (http://forums.sohc4.net/index.php/topic,150220.0.html)
2008 Triumph Thruxton (http://forums.sohc4.net/index.php/topic,190956.0.html)
2014 MV Agusta Brutale Dragster 800
2015 Yamaha FZ-09 (http://forums.sohc4.net/index.php/topic,186861.0.html)

"There are some things nobody needs in this world, and a bright-red, hunch-back, warp-speed 900cc cafe racer is one of them — but I want one anyway, and on some days I actually believe I need one.... Being shot out of a cannon will always be better than being squeezed out of a tube. That is why God made fast motorcycles, Bubba." Hunter S. Thompson, Song of the Sausage Creature, Cycle World, March 1995.  (http://www.latexnet.org/~csmith/sausage.html and https://magazine.cycleworld.com/article/1995/3/1/song-of-the-sausage-creature)

Sold/Emeritus
1973 CB750K2 "Bionic Mongrel" (http://forums.sohc4.net/index.php?topic=132734.0) - Sold
1977 CB750K7 "Nine Lives" Restomod (http://forums.sohc4.net/index.php?topic=50490.0) - Sold
2005 RVT1000RR RC51-SP2 "El Diablo" - Sold
2016+ Triumph Thruxton 1200 R (http://forums.sohc4.net/index.php/topic,170198.0.html) - Sold

Offline lennonG

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Re: first timer 1980 cb650c
« Reply #4 on: March 15, 2016, 10:24:39 PM »
little, but exciting update, i used some pliers, grabbed onto the freyed cable sticking out at the end of the throttle cable...


tried turning it over, pulled on the cable to give it some throttle, and she ran, rough, but ran for a bit! then the battery died.. trickle charger on it over night, gonna buy a multi meter tomorrow and check into that..

Offline SOHC4 Cafe Racer Fan

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Re: first timer 1980 cb650c
« Reply #5 on: March 16, 2016, 09:34:00 AM »
Sorry I couldn't email the service manual last night.  I didn't realize those files were so honking big!
1975 CB550K1 "Blue" Stockish Restomod (http://forums.sohc4.net/index.php?topic=135005.0)
1975 CB550F1 frame/CB650 engine hybrid "The Hot Mess" (http://forums.sohc4.net/index.php/topic,150220.0.html)
2008 Triumph Thruxton (http://forums.sohc4.net/index.php/topic,190956.0.html)
2014 MV Agusta Brutale Dragster 800
2015 Yamaha FZ-09 (http://forums.sohc4.net/index.php/topic,186861.0.html)

"There are some things nobody needs in this world, and a bright-red, hunch-back, warp-speed 900cc cafe racer is one of them — but I want one anyway, and on some days I actually believe I need one.... Being shot out of a cannon will always be better than being squeezed out of a tube. That is why God made fast motorcycles, Bubba." Hunter S. Thompson, Song of the Sausage Creature, Cycle World, March 1995.  (http://www.latexnet.org/~csmith/sausage.html and https://magazine.cycleworld.com/article/1995/3/1/song-of-the-sausage-creature)

Sold/Emeritus
1973 CB750K2 "Bionic Mongrel" (http://forums.sohc4.net/index.php?topic=132734.0) - Sold
1977 CB750K7 "Nine Lives" Restomod (http://forums.sohc4.net/index.php?topic=50490.0) - Sold
2005 RVT1000RR RC51-SP2 "El Diablo" - Sold
2016+ Triumph Thruxton 1200 R (http://forums.sohc4.net/index.php/topic,170198.0.html) - Sold

Offline knottedknickers

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Re: first timer 1980 cb650c
« Reply #6 on: March 16, 2016, 10:35:37 AM »
Sweet! Running--even roughly--is a treat! At least there's hope. ;)

I only have 750 manuals. Sorry I can't help you there... But you're in good hands with 'CB750 Cafe Racer Fan'--he'll get you set up with one (though he might want to use Dropbox or something like that?)
CB750 K6 http://forums.sohc4.net/index.php?topic=141388.0

The plural of "anecdote" is not "data" (Borgmann 2002:5).

Offline SOHC4 Cafe Racer Fan

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Re: first timer 1980 cb650c
« Reply #7 on: March 16, 2016, 01:38:52 PM »
Sweet! Running--even roughly--is a treat! At least there's hope. ;)

I only have 750 manuals. Sorry I can't help you there... But you're in good hands with 'CB750 Cafe Racer Fan'--he'll get you set up with one (though he might want to use Dropbox or something like that?)

Dropbox!  I didn't think of that.  I about ready to just mail him a CD with the pdfs on it.
1975 CB550K1 "Blue" Stockish Restomod (http://forums.sohc4.net/index.php?topic=135005.0)
1975 CB550F1 frame/CB650 engine hybrid "The Hot Mess" (http://forums.sohc4.net/index.php/topic,150220.0.html)
2008 Triumph Thruxton (http://forums.sohc4.net/index.php/topic,190956.0.html)
2014 MV Agusta Brutale Dragster 800
2015 Yamaha FZ-09 (http://forums.sohc4.net/index.php/topic,186861.0.html)

"There are some things nobody needs in this world, and a bright-red, hunch-back, warp-speed 900cc cafe racer is one of them — but I want one anyway, and on some days I actually believe I need one.... Being shot out of a cannon will always be better than being squeezed out of a tube. That is why God made fast motorcycles, Bubba." Hunter S. Thompson, Song of the Sausage Creature, Cycle World, March 1995.  (http://www.latexnet.org/~csmith/sausage.html and https://magazine.cycleworld.com/article/1995/3/1/song-of-the-sausage-creature)

Sold/Emeritus
1973 CB750K2 "Bionic Mongrel" (http://forums.sohc4.net/index.php?topic=132734.0) - Sold
1977 CB750K7 "Nine Lives" Restomod (http://forums.sohc4.net/index.php?topic=50490.0) - Sold
2005 RVT1000RR RC51-SP2 "El Diablo" - Sold
2016+ Triumph Thruxton 1200 R (http://forums.sohc4.net/index.php/topic,170198.0.html) - Sold

Offline Flatlander80

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Re: first timer 1980 cb650c
« Reply #8 on: March 16, 2016, 02:33:00 PM »
Congrats on the purchase! I have a 1980 CB 650 C that I got running last year, and may have some parts left over from combining 2 bikes. If you are indeed in Saskatoon, SK, I live about 45 min away.
Off the top of my head I have most of the front end, a clubman bar, spare tank (rough on the outside), maybe some other odds and ends. Haven't been through the parts since the fall!


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Offline lennonG

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Re: first timer 1980 cb650c
« Reply #9 on: March 16, 2016, 02:42:53 PM »
hey, thanks! I might be interested in some of ur stuff, once I start gettin more into it I'll let u know for sure!

Offline lennonG

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Re: first timer 1980 cb650c
« Reply #10 on: March 23, 2016, 07:47:01 PM »
so, I cleaned my gas tank (vinegar and salt) and it came out quite nice!



I also filled carbs with seafoam, left over night, and installed new throttle cables.

So i put battery back in, went to start it up and it worked! puffed white smoke (leftover seafoam I assume). It started, idled nice, then I shut it off. I went to start it again and every time it would start, Rev up to 6000 then go down and die. I'm thinking it's just the throttle cables just need to be better adjusted.

The bike also backfired, extremely loud whenever I revd it up.. I'm pretty happy it's running though! now to fine tune it, give the electrical a look over, ride and save money for some alterations!

I'm not sure this will work, but should be a link to the bike running and idling..
http://s663.photobucket.com/user/lennondg/media/VID_20160323_174956714.mp4.html
« Last Edit: March 23, 2016, 07:49:50 PM by lennonG »

Offline Flatlander80

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Re: first timer 1980 cb650c
« Reply #11 on: March 27, 2016, 07:50:11 AM »
I would check your timing advance. Mine was seized up and I couldn't rev the engine. The mechanism is under the front right cover, where you adjust the timing. Might have to pull it off and clean it.


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Offline SOHC4 Cafe Racer Fan

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Re: first timer 1980 cb650c
« Reply #12 on: March 27, 2016, 08:04:40 AM »
Did the manual on the CD arrive yet?
1975 CB550K1 "Blue" Stockish Restomod (http://forums.sohc4.net/index.php?topic=135005.0)
1975 CB550F1 frame/CB650 engine hybrid "The Hot Mess" (http://forums.sohc4.net/index.php/topic,150220.0.html)
2008 Triumph Thruxton (http://forums.sohc4.net/index.php/topic,190956.0.html)
2014 MV Agusta Brutale Dragster 800
2015 Yamaha FZ-09 (http://forums.sohc4.net/index.php/topic,186861.0.html)

"There are some things nobody needs in this world, and a bright-red, hunch-back, warp-speed 900cc cafe racer is one of them — but I want one anyway, and on some days I actually believe I need one.... Being shot out of a cannon will always be better than being squeezed out of a tube. That is why God made fast motorcycles, Bubba." Hunter S. Thompson, Song of the Sausage Creature, Cycle World, March 1995.  (http://www.latexnet.org/~csmith/sausage.html and https://magazine.cycleworld.com/article/1995/3/1/song-of-the-sausage-creature)

Sold/Emeritus
1973 CB750K2 "Bionic Mongrel" (http://forums.sohc4.net/index.php?topic=132734.0) - Sold
1977 CB750K7 "Nine Lives" Restomod (http://forums.sohc4.net/index.php?topic=50490.0) - Sold
2005 RVT1000RR RC51-SP2 "El Diablo" - Sold
2016+ Triumph Thruxton 1200 R (http://forums.sohc4.net/index.php/topic,170198.0.html) - Sold

Offline lennonG

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Re: first timer 1980 cb650c
« Reply #13 on: March 27, 2016, 05:42:09 PM »
CD didn't get here yet, probably this week though!

and flatlander, do you think that timing advance would be a reason for it reving for no reason?

Offline Flatlander80

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Re: first timer 1980 cb650c
« Reply #14 on: March 29, 2016, 12:34:15 PM »
CD didn't get here yet, probably this week though!

and flatlander, do you think that timing advance would be a reason for it reving for no reason?

I can't see a stuck timing advance causing the engine to race. I might defer to the waaaaay more mechanically inclined, but I'd say that would be due to carberation (either a vacuum leak or something not quite right yet.

Offline flatlander

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Re: first timer 1980 cb650c
« Reply #15 on: March 29, 2016, 12:52:29 PM »
CD didn't get here yet, probably this week though!

guys, next time try this - beats the postal system: https://www.wetransfer.com/

and flatlander, do you think that timing advance would be a reason for it reving for no reason?

you talkin to me???
 ;)

Offline lennonG

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Re: first timer 1980 cb650c
« Reply #16 on: March 29, 2016, 04:56:21 PM »
haha too many flatlanders!

turns out, it was racing like that because the throttle cables weren't adjusted right (whoops)

also, just adding to my fun, sitting on bike looking down, the right 2 pipes don't get hot at all when I ran it, so running on 2 cylinders! gonna check spark plugs tonight, maybe ignition coil?

also, I'm going to take the carbs off and thoroughly clean them, must be done!

Offline Flatlander80

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Re: first timer 1980 cb650c
« Reply #17 on: March 29, 2016, 05:06:46 PM »
Doubt it's a coil... Since 3 and 4 cylinders don't have spark, and they run off different coils... And there are only 2... Anyhow, check plugs and plug wires.

And throttle cables need a bit of slack, or they kinda bind up. My cousins bike had the cables tight, and it was super touchy on and off throttle. Anyhow, sounds like you're making progress and fixing gremlins. I was out working on mine today... Might have to post some pics...


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Offline lennonG

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Re: first timer 1980 cb650c
« Reply #18 on: March 30, 2016, 12:19:00 AM »
so plug in cylinder #4 was covered in oil, need a thinner socket to get out #3..


also my oil pan gasket is leaking, I'm pretty sure the PO put the engine together all finger tight.. oil.. everywhere!

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Offline lennonG

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Re: first timer 1980 cb650c
« Reply #19 on: March 31, 2016, 05:09:10 PM »
well, I took the carbs off the bike! should it be bent like that where the push throttle cable hooks up?



also inside the bowls was a lot of gunk..



Not sure if I should get carb rebuild kits, or just gaskets? would these be the right kit?



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Offline SOHC4 Cafe Racer Fan

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Re: first timer 1980 cb650c
« Reply #20 on: March 31, 2016, 05:41:37 PM »
That kind of carb gravy is pretty mild.  It'll still gum up your mixture, but it should be easy to clean.  The nasty nasty stuff looks like dried resin, and corrodes the brass needles.
1975 CB550K1 "Blue" Stockish Restomod (http://forums.sohc4.net/index.php?topic=135005.0)
1975 CB550F1 frame/CB650 engine hybrid "The Hot Mess" (http://forums.sohc4.net/index.php/topic,150220.0.html)
2008 Triumph Thruxton (http://forums.sohc4.net/index.php/topic,190956.0.html)
2014 MV Agusta Brutale Dragster 800
2015 Yamaha FZ-09 (http://forums.sohc4.net/index.php/topic,186861.0.html)

"There are some things nobody needs in this world, and a bright-red, hunch-back, warp-speed 900cc cafe racer is one of them — but I want one anyway, and on some days I actually believe I need one.... Being shot out of a cannon will always be better than being squeezed out of a tube. That is why God made fast motorcycles, Bubba." Hunter S. Thompson, Song of the Sausage Creature, Cycle World, March 1995.  (http://www.latexnet.org/~csmith/sausage.html and https://magazine.cycleworld.com/article/1995/3/1/song-of-the-sausage-creature)

Sold/Emeritus
1973 CB750K2 "Bionic Mongrel" (http://forums.sohc4.net/index.php?topic=132734.0) - Sold
1977 CB750K7 "Nine Lives" Restomod (http://forums.sohc4.net/index.php?topic=50490.0) - Sold
2005 RVT1000RR RC51-SP2 "El Diablo" - Sold
2016+ Triumph Thruxton 1200 R (http://forums.sohc4.net/index.php/topic,170198.0.html) - Sold

Offline lennonG

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Re: first timer 1980 cb650c
« Reply #21 on: April 01, 2016, 08:12:07 PM »
yea, the carbs don't actually look all that bad besides the bit of gunk! I'm thinking maybe just getting some new gaskets, everything else looks perfect..

besides this

accelerator pump must have been getting water in there (didn't find the small gasket clymers manual warns you not to lose)... not even sure I can get a replacement?

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Offline JimJamerino

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Re: first timer 1980 cb650c
« Reply #22 on: April 04, 2016, 12:54:09 PM »
Yes, you can get replacement accelerator pumps. It comes in one piece, the pump diaphragm with the Mickey Mouse ears and rod. Mine came with the itty bitty o-ring for the pump housing, too. Partsnmore.com is where I got mine a couple years ago.
~ Jim

formerly "emperorspartacus"

There are old bikers.  There are dumb bikers.  There are no old, dumb bikers.

My CB650C rebuild http://forums.sohc4.net/index.php?topic=74212.0