Author Topic: 1980 CB650 Custom, restored and back on the road!  (Read 5563 times)

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Offline ABikeNamedTrouble

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1980 CB650 Custom, restored and back on the road!
« on: October 20, 2011, 02:12:43 PM »
Well, after owning this bike for 5 months, and riding it daily for 2, I figure it's time I made a thread and showed everybody what I did.  There is absolutely no way I could have done this project without the folks on this forum, and I can only hope to repay the debt by helping others on their projects.

So Thank you, all of you!


Here we go!

As delivered for a meager $600.  Great cosmetic shape for being 30 years old.  Mechanically, however, things were a different story.  The headgasket was leaking oil; cam chain tensioner was broken; the carbs were leaky, covered in silicone, and two slowjets were seriously clogged such that it was firing on only two cylinders; the rotor and R/R needed replaced; the wire harness was pinched to the frame in 3 different spots; the tires wouldn't hold air; and a dozen other small things needed fixed.


Step 1: Carbs!  Disassemble, clean, replace slow jets, all new rubber everything, reassemble and bench-sync.


Step 2: Top-end rebuild!  Disassemble, clean all surfaces, valve re-lap, replace cam chain tensioner, check clearances, reassemble with new Athena gaskets, helicoil inserts on two stripped cam-cover bolts, and re-torque everything.





Step 3: Be dumb and install pod filters.  This ended up being MUCH more of a headache than it was worth, and I eventually went back to the stock air box and jetting.  Still, I love the muscle-bike look it gives the engine.


Step 4:  Ignition!  Repotted the melted spark units with JB weld, replaced broken ignition coil, cleaned and oiled spark advancer, installed new plug wires, and set timing (Sorry I didn't get pictures of all that).



Step 5: Carb tuning!  Vacuum sync the carbs after all the other things got fixed.  The guy in the picture is my good buddy Daniel, who, though he is a heretic (a.k.a. Honda DOHC rider), also happens to be a genius and I never could have done this project without him :)



Step 6: Clutch rebuild!  I didn't get pictures of this, but I did make my own version of Honda's $38 clutch adjuster locknut tool.  Cost me $6 :)


Step 7:  Talk about everything else!  I didn't get picture of my rotor and R/R replacement, mostly because I was too angry to get my camera out!  The charging system on this bike is a serious PITA, but I eventually got it settled.  Also not pictured is polishing the engine covers and the three-week-long hunt for properly sized o-rings for my carb drain bowls.  I eventually used two 4.5X1mm o-rings on each drain screw and it seems to work like a charm. 

Step 8:  RIDE!
 

- Adam

1980 CB650c Custom
Keihin PD mechanical carbs
Stock air box and 4-4 exhaust
http://forums.sohc4.net/index.php?topic=97504.0

Offline cb650

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Re: 1980 CB650 Custom, restored and back on the road!
« Reply #1 on: October 20, 2011, 04:35:59 PM »
Nice!!!!
18 grand and 18 miles dont make you a biker

Offline Ouch

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Re: 1980 CB650 Custom, restored and back on the road!
« Reply #2 on: October 21, 2011, 08:14:23 AM »
NICE!!!!

Offline wardenerd

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Re: 1980 CB650 Custom, restored and back on the road!
« Reply #3 on: October 21, 2011, 08:50:23 AM »
I HEART your tank!

Offline weltzing

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Re: 1980 CB650 Custom, restored and back on the road!
« Reply #4 on: March 14, 2012, 10:24:55 PM »
Hello ABikeNamedTrouble,
I know this is an older thread but I have a few questions!!!
I have the same bike as you do and am having some problems. When you took all the carbs apart, how hard was it to reassemble them together? Did you find some carb kits? You said you replaced the slow jets, do you mean you found new ones or you just cleaned the old ones and put them back in? Mine are always gunked up...and for the spark units, mine are also all gooey so when I go to use your JB weld trick, do I just plop some in there and level it off?
Thanks !

Offline wardenerd

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Re: 1980 CB650 Custom, restored and back on the road!
« Reply #5 on: March 15, 2012, 03:58:21 AM »
I am glad you got it running.  We ride the bastard son of SOHC but they sure are fun. 

Offline Maquina

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Re: 1980 CB650 Custom, restored and back on the road!
« Reply #6 on: May 09, 2012, 04:10:30 AM »
Hi there ... Awesome job... Hey I was wondering if you could help me.... I am about to replace the head gasket on my 81 cb650.

I noticed the head gasket metal rings has different finishes on each side... One side is more less flat while the other side looks like the metal ring has a slight bevel with with obvious machining marks on it... The manual says to install the gasket with the wider turned ring side facing up.... Did you notice this when you re did the engine?

Any help would be great.. I don't wanna end up installing it wrong side up and waisting 90buks for such a small mistake.

Tank you.

Offline curemode2002

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Re: 1980 CB650 Custom, restored and back on the road!
« Reply #7 on: May 09, 2012, 09:46:16 AM »
Looks awesome! I just got all the mechanical and electrical done on mine now I need to work on the cosmetic stuff.

P.S.
weltzing
Carb stuffs for this model can be found at www.siriusconinc.com, and z1enterprises.com
Bikes:
1980 CB650 Sold
2015 Monster 821 Stripe

Offline Maquina

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Re: 1980 CB650 Custom, restored and back on the road!
« Reply #8 on: May 11, 2012, 02:37:03 AM »
Omg s.c.i. Is the bomb!.... It's about the only place I found a new choke cable cuz mine broke from being rusted through... Cheap prices too and fast shipping took about a week to get my cable from Canada to San Diego.