Topic: Before I undertake this epic starter clutch repair...

[Autoground]

Hey all! So I've been putting it off for forever-- my 1980 cb650 starter clutch that only works after the bike has been running for awhile. From a cold start it simply won't get the job done, and I have to bump start it down the driveway anytime I ride.

So there's this repair that some of you are probably aware of:
http://slagheapcycles.blogspot.com/2015/06/cb650-sohc-starter-clutch-removal-and.html
and
http://archives.sohc4.net/index.php?topic=9916.0
and
A .pdf walkthrough replete with pics and parts numbers


I'm all set to do it. I've ordered parts, etc.

BUT BEFORE I DO!
JUST TO MAKE SURE I'M NOT DOING THIS EPIC FRUSTRATING REPAIR WHEN I DON'T HAVE TO...

What can I do to make sure that this repair is necessary? I've tried starting the bike with a second battery supplementing my battery (to make sure the issue wasn't a weak battery). I've check the connections on the starter motor.

What else can I do to rule out having to do this intimidating surgery?

Thanks, guys!

[Autoground]

I suppose I should mention that when attempting a cold start, I get the marbles in a blender sound. The bike runs well otherwise.

I have some zinc additive in my oil. Not sure what else could be pertinent.

I'm nervous about doing this repair, though I am not completely inexperienced with moto surgery. I asked the local honda motorcycle shop if he'd do it, and he said he's retiring and not up for the complicated jobs. 

[bryanj]

Sounds like the springs are gummed up and/or weak, its also possible the big gear has lots of "flats" on the machined surface the rollers catch on, this would mean new gear as if you polish it round its then too small

[jonda500]

I have exactly the same problem with my 72 cb500, but fortunately I have a kickstarter to use for cold starts.
Amongst much other neglect and abuse, the PO of my bike had removed and discarded the kicker and shoehorned a small car battery in it - I believe he wore out the starter clutch rather than ever fixing anything. Works fine when the engine's hot so with a working kicker, I just can't seem to get around to fixing it - I saved a link to a starter clutch replacing (through the sump) thread in my signature below. Sounds to me like your starter clutch (like mine) indeed needs replacing. Let us know how it goes if you go through with it!
John

[Don R]

 The Goldwing guys use a high detergent oil like high mileage castrol or an additive like Rislone or Seafoam and slightly overfill to get the oil into the starter clutches to remove varnish in the starter sprag.
  One method is engage the starter with the engine idling. I've never felt the need to try it but they say it can work. I realize they are totally different engines and it will only help if varnish is the cause.

[kerryb]

I just did that repair following the linked instruction thread.  Here's what I learned...
1. Take the engine out and put it on a stand upside down.  I can't imagine doing this job with the engine still in the bike!
2. The job really isn't difficult, just follow those directions and label everything.   Make sure you pull the starter, it allows clearance to get enough room to get the starter clutch out.
3.  The screws holding the starter clutch on are torx head screws.  An allen wrench will work, or it did for me because I didn't know they were torx.

Good luck.

[dave500]

ive replaced the starter clutch in a 500 in the frame,its a fiddle but can be done,i did a detailed post a bout it which another fella followed and got it done aswell,the 650 should be pretty close if not the same,ill dig up a link to that thread,only took couple of hours.

[dave500]

that thread must be way back ive looked,had a lot of photos that wont be there now because of the photobucket shut down.

[Autoground]

Thanks for the notes of encouragement, fellas.

I'm going step-by-step from a great write-up by a guy with a good sense of humor. I'm taking it slow, only a few steps a day in my spare time. It's going well enough.

After this, the bike should be 100%! Very exciting.