Author Topic: 79 CB 650 refurb turns resto / mod  (Read 33848 times)

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Offline thrutheframe

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79 CB 650 refurb turns resto / mod
« Reply #175 on: February 22, 2012, 06:27:44 am »
Wow!  That's a lot of parts.
'74 cb 750 K4
'79 CB 650 http://forums.sohc4.net/index.php?topic=83981.0
'75 CB 360T
'90 RC31 Hawk GT

Offline thrutheframe

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79 CB 650 refurb turns resto / mod
« Reply #176 on: February 22, 2012, 07:11:39 pm »
 I got thru the carb bodies for 1&2 and the throttle spring and cam before the fumes ran me out.  I'll do one or two more carb bodies tomorrow before work. 
  At this point I'm waiting on:
Aircraft Stripper
Carb Kits
Accelerator Pump Diaphragm
Air Cut Off Valve Kits
Petcock Kit for my test tank
Center Stand Hardware

  I still have buy / fund:
Paint Job $$$$$
Petcock for real tank
Gas Cap for real tank
Front Turn Signals
Mirrors (if I decide I don't like the bar end mirrors)

The future might hold:
Frame paint job
Cafe or 750 K style seat
Spoke Wheels
 


'74 cb 750 K4
'79 CB 650 http://forums.sohc4.net/index.php?topic=83981.0
'75 CB 360T
'90 RC31 Hawk GT

Offline Jay_kent

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Re: 79 CB 650 refurb turns resto / mod
« Reply #177 on: February 22, 2012, 08:11:53 pm »
Sure are a lot of parts for a set of carbs. Looking good though
"I am always doing that which I cannot do, in order that I may learn how to do it."
   Pablo Picasso
More pics at my Cafe build blog - Here

Offline thrutheframe

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79 CB 650 refurb turns resto / mod
« Reply #178 on: February 25, 2012, 10:12:12 am »
  I got my aircraft stripper yesterday.  Interesting label warning.
'74 cb 750 K4
'79 CB 650 http://forums.sohc4.net/index.php?topic=83981.0
'75 CB 360T
'90 RC31 Hawk GT

Offline thrutheframe

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79 CB 650 refurb turns resto / mod
« Reply #179 on: February 26, 2012, 12:24:26 pm »
New slack adjuster hardware and rear brake hardware including the spring.  I've had these parts lying around for awhile and decided to put them on today after I cleaned more carb parts.
« Last Edit: February 26, 2012, 12:26:57 pm by thrutheframe »
'74 cb 750 K4
'79 CB 650 http://forums.sohc4.net/index.php?topic=83981.0
'75 CB 360T
'90 RC31 Hawk GT

Offline thrutheframe

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79 CB 650 refurb turns resto / mod
« Reply #180 on: February 27, 2012, 12:20:35 pm »
  Taking a break from the shop for a few, I saw UPS down the street.  I'm going to wait for him and see if he brings my carb kits and diaphragms or just the stuff from bike bandit.  I had the 650 running earlier but found a leaky carb. Luckily these are NOT the carbs I've been throwing money at.
'74 cb 750 K4
'79 CB 650 http://forums.sohc4.net/index.php?topic=83981.0
'75 CB 360T
'90 RC31 Hawk GT

Offline thrutheframe

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79 CB 650 refurb turns resto / mod
« Reply #181 on: February 27, 2012, 12:32:08 pm »
« Last Edit: February 27, 2012, 04:53:31 pm by thrutheframe »
'74 cb 750 K4
'79 CB 650 http://forums.sohc4.net/index.php?topic=83981.0
'75 CB 360T
'90 RC31 Hawk GT

Offline Jay_kent

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Re: 79 CB 650 refurb turns resto / mod
« Reply #182 on: February 27, 2012, 12:45:29 pm »
Things are starting to come together. Didn't get what you were showing though with that link.
"I am always doing that which I cannot do, in order that I may learn how to do it."
   Pablo Picasso
More pics at my Cafe build blog - Here

Offline thrutheframe

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79 CB 650 refurb turns resto / mod
« Reply #183 on: February 27, 2012, 03:55:04 pm »
I think the link is wrong, added it from my phone.  I had it running today, twice.  Running, found carb leak, carbs off fixed leak, back on, running.  I'll fix the link in a few when I go out where I can get on the web.
  Tomorrow I'm going to double check the charging system and put the seat and mirrors on it and try to get it out on the road.
'74 cb 750 K4
'79 CB 650 http://forums.sohc4.net/index.php?topic=83981.0
'75 CB 360T
'90 RC31 Hawk GT

Offline thrutheframe

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'74 cb 750 K4
'79 CB 650 http://forums.sohc4.net/index.php?topic=83981.0
'75 CB 360T
'90 RC31 Hawk GT

Offline Jay_kent

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Re: 79 CB 650 refurb turns resto / mod
« Reply #185 on: February 27, 2012, 08:26:53 pm »
sounds awesome. Sounds like it's idling pretty good. Still snow and ice up here so I'll be waiting a little longer.
"I am always doing that which I cannot do, in order that I may learn how to do it."
   Pablo Picasso
More pics at my Cafe build blog - Here

Offline thrutheframe

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Re: 79 CB 650 refurb turns resto / mod
« Reply #186 on: February 28, 2012, 04:31:21 am »
  It idles pretty well. I have it set at just over 1200.  I THINK its running rich right now. It will take throttle on a nice even twist but if I nail it, it makes that sucking sound and wants to stall.  It took gas better with the choke on so I figured it was lean.  I turned the mix screws in all the way, came out to +1/2 turn and it was worse.  I came out another 1/2 turn and its better but still not right.  Based on the response to the mix screw settings I think it's rich, is my logic coreect? I'm going to come out another 1/2 turn once I get ready to take it out today.  The carbs are PD 26/50A's with stock slow jets, 110 mains, pod filters and the air cut off circuits have been bypassed.  These are NOT the carbs I'll be running on this bike but any advise anyone has would be much appreciated.
« Last Edit: February 28, 2012, 04:33:24 am by thrutheframe »
'74 cb 750 K4
'79 CB 650 http://forums.sohc4.net/index.php?topic=83981.0
'75 CB 360T
'90 RC31 Hawk GT

Offline thrutheframe

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79 CB 650 refurb turns resto / mod
« Reply #187 on: February 28, 2012, 04:40:35 am »
I picked up this little gem yesterday.  I used a little grease to get it in the hole past the first ring.
'74 cb 750 K4
'79 CB 650 http://forums.sohc4.net/index.php?topic=83981.0
'75 CB 360T
'90 RC31 Hawk GT

Offline thrutheframe

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79 CB 650 refurb turns resto / mod
« Reply #188 on: February 28, 2012, 05:33:09 am »
Idle....
'74 cb 750 K4
'79 CB 650 http://forums.sohc4.net/index.php?topic=83981.0
'75 CB 360T
'90 RC31 Hawk GT

Offline thrutheframe

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79 CB 650 refurb turns resto / mod
« Reply #189 on: February 28, 2012, 05:34:45 am »
4000 rpm
« Last Edit: March 01, 2012, 04:25:20 am by thrutheframe »
'74 cb 750 K4
'79 CB 650 http://forums.sohc4.net/index.php?topic=83981.0
'75 CB 360T
'90 RC31 Hawk GT

Offline thrutheframe

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79 CB 650 refurb turns resto / mod
« Reply #190 on: February 28, 2012, 08:51:38 am »
It runs really well warmed up.  The curve isn't 100% linear but it's very manageable. It idles nice and it's really smooth and easy to manage at parking lot speeds.  I'm not going to worry about dialing in this set of carbs further than they are.  I'll have my carb parts soon.
  There is some bad news. The head is going to have to come off.   It's leaking oil still.  It's coming from the head, in front of and out board of cylinder 1.
'74 cb 750 K4
'79 CB 650 http://forums.sohc4.net/index.php?topic=83981.0
'75 CB 360T
'90 RC31 Hawk GT

Offline Jay_kent

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Re: 79 CB 650 refurb turns resto / mod
« Reply #191 on: February 28, 2012, 08:54:33 am »
wonder if it's not tightening enough, I'm having the same problem on two engines and when I rebuilt the first one, I didn't chase the holes. The bolts were oxidized and perhaps there is some crud still on the bottom.
Either that or the head isn't flat.

"I am always doing that which I cannot do, in order that I may learn how to do it."
   Pablo Picasso
More pics at my Cafe build blog - Here

Offline Killer Canary

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Re: 79 CB 650 refurb turns resto / mod
« Reply #192 on: February 28, 2012, 08:59:57 am »
I've found in the past that after I've done a top end job, there would be leaks on startup; I would put a few miles on and then retorque stuff. That might do it for you. Doesn't cost anything.
If it's worth doing at all it's worth over-doing.
Honda CB400F CB550, GL500, CBR929, MT250
Kawi GPz900, H1
Suzuki GS550

Offline thrutheframe

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79 CB 650 refurb turns resto / mod
« Reply #193 on: March 01, 2012, 03:17:54 am »
Christmas!
'74 cb 750 K4
'79 CB 650 http://forums.sohc4.net/index.php?topic=83981.0
'75 CB 360T
'90 RC31 Hawk GT

Offline Jay_kent

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Re: 79 CB 650 refurb turns resto / mod
« Reply #194 on: March 01, 2012, 06:28:19 am »
fantastic
"I am always doing that which I cannot do, in order that I may learn how to do it."
   Pablo Picasso
More pics at my Cafe build blog - Here

Offline thrutheframe

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79 CB 650 refurb turns resto / mod
« Reply #195 on: March 01, 2012, 08:52:56 am »
   Jay here is where I pick your brain if I may.....
  Back to the plastic spacer.  Is thus the correct location? It's in carb 2 obviously at the linkage on the accelerator pump side. Correct?  Also please confirm that carb 3 is the one with no slide height adjuster.

Thanks.
'74 cb 750 K4
'79 CB 650 http://forums.sohc4.net/index.php?topic=83981.0
'75 CB 360T
'90 RC31 Hawk GT

Offline thrutheframe

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79 CB 650 refurb turns resto / mod
« Reply #196 on: March 01, 2012, 08:55:30 am »
Duh just read your reply from my initial query , it looks like I have it correct.
'74 cb 750 K4
'79 CB 650 http://forums.sohc4.net/index.php?topic=83981.0
'75 CB 360T
'90 RC31 Hawk GT

Offline Jay_kent

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Re: 79 CB 650 refurb turns resto / mod
« Reply #197 on: March 01, 2012, 09:03:25 am »
I'll take a look and upload some images that I took when I tore down my carbs tonigh. It'll give you a better clue, unless your anxious to get these things done  ;), but I think carb 2 isn't adjustable for the slide

One trick I did when tensioning the throttle spring between carb 3 and 4, was to hook the spring on both carbs loose then rotated carb four around the throttle shaft while holding carb for stationary. I counted 12 turns on the spring before I took it off and got the spring tensioned that way. Then I put in the rest of the small pipes for fuel and overflow and connected the 2 together


Hope this makes sense
"I am always doing that which I cannot do, in order that I may learn how to do it."
   Pablo Picasso
More pics at my Cafe build blog - Here

Offline thrutheframe

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79 CB 650 refurb turns resto / mod
« Reply #198 on: March 01, 2012, 10:09:48 am »
The bike runs... I'm patient
'74 cb 750 K4
'79 CB 650 http://forums.sohc4.net/index.php?topic=83981.0
'75 CB 360T
'90 RC31 Hawk GT

Offline Jay_kent

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Re: 79 CB 650 refurb turns resto / mod
« Reply #199 on: March 01, 2012, 07:54:59 pm »
As promised, here is a before shot of carbs 2&3, 2 is on the left:


The plastic washer on the throttle shaft, carb 2:


A plastic washer on the part where the throttle cables end connect to:


Detail image of the choke spring assembly:




Hope these images help
"I am always doing that which I cannot do, in order that I may learn how to do it."
   Pablo Picasso
More pics at my Cafe build blog - Here

 

;
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