Author Topic: '79 CB650 Barn Bike  (Read 925 times)

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Offline t.reid657

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'79 CB650 Barn Bike
« on: May 23, 2019, 12:29:30 PM »
Hey Folks,

Just last week I found a decently clean 79 CB650 at a barn sale, no title, and hasn't turned over in a dozen years. The price was too good to pass up and I drove home with it against all better judgement or reason. I've not done much work on it yet, as I had to petition my local court for a new title to be issued and I don't want to get too far ahead of myself if it doesn't go through for whatever reason. After a fairly thorough inspection, she has everything except for the stock exhausts (they look to be from another model, maybe a CB750?) and the air chamber that sits directly behind the carbs. The carbs, engine, and transfer case all are fairly clean on the inside for having sat over a decade, and I'm chomping at the bit to start working on it. My thoughts were to do a carb and engine rebuild (the gaskets must be like paper after so long) before going through the electrical components one by one to figure out why it hasn't run in so long. Any tips for a first time SOHC4 rebuild would be appreciated, as I've worked on car engines before but never any motorcycles.

-T

Offline jgger

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Re: '79 CB650 Barn Bike
« Reply #1 on: May 23, 2019, 12:45:50 PM »
Looks pretty good. Also from that picture it does look like stock exhaust. The 79 had a 4 into 2 system, is there any markings on the mufflers?
"The SOHC4 uses a computer located about 2-3 ft above the seat.  Those sometimes need additional programming." -stolen from  Two Tired

The difference between an ass kisser and brown noser is merely depth perception.  Stolen from RAFster122s

Offline t.reid657

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Re: '79 CB650 Barn Bike
« Reply #2 on: May 23, 2019, 01:02:32 PM »
Looks pretty good. Also from that picture it does look like stock exhaust. The 79 had a 4 into 2 system, is there any markings on the mufflers?


Not that I've been able to find. They do look original in the picture, but the brackets to hold them on aren't at the right spot to be bolted to the bike. They are actually held on by cable ties in the pics. They also have a bit of pipe that runs perpendicular to the muffler for what I assume was another fastening point.

Offline jgger

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Re: '79 CB650 Barn Bike
« Reply #3 on: May 23, 2019, 01:49:08 PM »
You are right, stock exhaust is more upswept in the back. If there is writing on the mufflers it is on top between the front and back foot pegs. It does look like it will be difficult to pull your rear alle out though.

Here is my junk stock exhaust.
"The SOHC4 uses a computer located about 2-3 ft above the seat.  Those sometimes need additional programming." -stolen from  Two Tired

The difference between an ass kisser and brown noser is merely depth perception.  Stolen from RAFster122s

Offline t.reid657

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Re: '79 CB650 Barn Bike
« Reply #4 on: May 23, 2019, 02:03:04 PM »
It wasn't too hard to get them off, other than the two bolts holding them into the cylinder head, the pipes were only attached by the cable tie. I'll probably sell them for scrap because of some rust at the joint where the 2 exhaust manifold pipes meet the muffler. I found another '79 650 being parted out by a scrapyard, and the guy told me he'd give me both pipes for $47 each (!) unfortunately he's not interested in selling the whole thing at once though.

Offline Bankerdanny

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Re: '79 CB650 Barn Bike
« Reply #5 on: May 23, 2019, 02:59:33 PM »
The '79 is my favorite 650 because it was an evolution of the '78 550 stylewise. Most of the 80-82 SOHC 650's took on a cruiser look (except the Nighthawk versions).

The '79 gives you a more classic SOHC4 look with the more powerful engine.
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Current: '76 CB750F. Previous:  '75 CB550F, 2007 Yamaha Vino 125 Scooter, '75 Harley FXE Superglide, '77 GL1000, '77 CB550k, '68 Suzuki K10 80, '68 Yamaha YR2, '69 BMW R69S, '71 Honda SL175, '02 Royal Enfield Bullet 500, '89 Yamaha FJ1200