A rebuild is looming; EDIT: Maybe not....bad carb synch?

If it's broken or just needs tweaked

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scott s
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Re: A rebuild is looming; EDIT: Maybe not....bad carb synch?

Postby scott s » Wed Aug 14, 2013 1:14 pm


cb650
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Re: A rebuild is looming; EDIT: Maybe not....bad carb synch?

Postby cb650 » Wed Aug 14, 2013 2:06 pm

Nice bike but put the cam chain adjuster in properly.
Many threads and pics on it. Easy thing to get wrong.
Did you clean the tank out?!?!?!?!

scott s
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Re: A rebuild is looming; EDIT: Maybe not....bad carb synch?

Postby scott s » Wed Aug 14, 2013 6:17 pm

I never had the cam adjuster out.

I adjusted it per the manual. Loosen lock-nut, rotate engine clockwise while re-tightening the locknut. Guess that's all I can do. :?

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Volker_P
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Re: A rebuild is looming; EDIT: Maybe not....bad carb synch?

Postby Volker_P » Thu Aug 15, 2013 3:20 am

Now I listened to the video.
All I hear is some clutch rattle, here in fact carb synchronization may help.

scott s wrote:Well, you can't check the cam chain tension at the sprocket on a CB650.

There should be a small cutout in that sprocket cover at the front side. Not large, but sufficient for view and a small screwdriver.

Anyway, I do not hear any abnormal valve noise in the videos that may be reduced by adjustment.

The cam chain tensioner procedure sometimes needs a few efforts or may even make it worse. That's why the screwdriver check makes some sense.
Cosky's great (free) online manual: http://cosky0.tripod.com

forum links to common technical issues

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scott s
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Re: A rebuild is looming; EDIT: Maybe not....bad carb synch?

Postby scott s » Thu Aug 15, 2013 6:15 am

Well, shoot....it's all back together now. Anyone have a pic of that window so I know what I'm looking at next time?
Doesn't really matter, as there's nothing you can do about it other than replace cam chain, right?

Are there any other cam chain adjustment tricks?

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Re: A rebuild is looming; EDIT: Maybe not....bad carb synch?

Postby cb650 » Thu Aug 15, 2013 8:32 am

scott s wrote:I never had the cam adjuster out.

I adjusted it per the manual. Loosen lock-nut, rotate engine clockwise while re-tightening the locknut. Guess that's all I can do. :?

Someone did. Or did you buy it new? You can drop the pan and see.
Did you clean the tank out?!?!?!?!

scott s
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Re: A rebuild is looming; EDIT: Maybe not....bad carb synch?

Postby scott s » Thu Aug 15, 2013 2:42 pm

I bought the engine in a bare frame, along with a pile of parts, from Craigslist for, I think, $175.

Can you tell me a little more about the cam chain deal you're talking about? Is it something that can be fixed with the engine in the frame?

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Re: A rebuild is looming; EDIT: Maybe not....bad carb synch?

Postby cb650 » Thu Aug 15, 2013 5:56 pm

Yes Pull the pan and see if it is out. Threads with pics here. Super V ( :lol: ) will post a link shortly if its not the one he already did.
Did you clean the tank out?!?!?!?!

cb650
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Re: A rebuild is looming; EDIT: Maybe not....bad carb synch?

Postby cb650 » Thu Aug 15, 2013 5:56 pm

Yes Pull the pan and see if it is out. Threads with pics here. Super V ( :lol: ) will post a link shortly if its not the one he already did.


Found a pic in this thread. The end of the adjuster shouldnt show like it is in the pic. viewtopic.php?f=2&t=8052&start=195


Its hit on in some of the starter clutch threads too.
Some of the old pics are missing from the threads now.


Again wish would have taken more pics when we did Adams (now mine) bike.
Did you clean the tank out?!?!?!?!

scott s
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Re: A rebuild is looming; EDIT: Maybe not....bad carb synch?

Postby scott s » Thu Aug 15, 2013 6:52 pm

They're talking about the primary chain tensioner. I'm hearing noise up top, like maybe it's the cam chain. Or am I not understanding what you're trying to tell me? :?:

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Re: A rebuild is looming; EDIT: Maybe not....bad carb synch?

Postby scott s » Thu Aug 15, 2013 7:00 pm

Looking back through pics I took when I was building the bike... do these tell you anything?

Image
Image
Image
Image

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Re: A rebuild is looming; EDIT: Maybe not....bad carb synch?

Postby scott s » Thu Aug 15, 2013 7:06 pm

Volker_P wrote:Now I listened to the video.
All I hear is some clutch rattle, here in fact carb synchronization may help.

scott s wrote:Well, you can't check the cam chain tension at the sprocket on a CB650.

There should be a small cutout in that sprocket cover at the front side. Not large, but sufficient for view and a small screwdriver.



Found this pic in my folder, too. I don't see a cut out on the cover.

Image

I never took the head off, just the valve cover so that we could fit it in the CB500 frame. I've never had the cam chain off the gear, personally.

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Re: A rebuild is looming; EDIT: Maybe not....bad carb synch?

Postby cb650 » Fri Aug 16, 2013 12:12 am

Pic with the pan off is what is needed. is close but cant see the area very good..
Did you clean the tank out?!?!?!?!

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Volker_P
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Re: A rebuild is looming; EDIT: Maybe not....bad carb synch?

Postby Volker_P » Fri Aug 16, 2013 1:38 am

There are several options for cam chain tensioner problems
(although I do not hear something like that in the video)

1. Cam chain tensioner mounted misaligned:
To be checked via the oil pan, see pictures in Ibsen's Replacing the cam chain tensioner thread.

2. Tensioner stuck:
One can try to open the second, upper bolt, too. This may help to get a stuck tensioner free. But open just a turn, no idea if one could put it back if you remove it completely (although I know of someone who managed it at a 500. However he kept the adjustment nut fixed because he had to take bolt out only to retorque the head bolt beneath).

3. Cam chain worn

Below a picture of the cutout for the screwdriver check. :wink:
Attachments
Chaintunnela30.jpg
Chaintunnela30.jpg (41.59 KiB) Viewed 12836 times
Cosky's great (free) online manual: http://cosky0.tripod.com

forum links to common technical issues

If you really like this site and you would not like to see it vanish soon, have a look there: Urgent: Future of HondaCB650.com Forum

scott s
Posts: 131
Joined: Sun Nov 18, 2012 6:40 am
Location: Rock Hill, SC

Re: A rebuild is looming; EDIT: Maybe not....bad carb synch?

Postby scott s » Sun Nov 17, 2013 10:37 am

Well, after looking closely at the pics and wishing very badly that it wasn't so, I believe that CB650 is right: I think the cam chain adjuster is installed incorrectly.

This pic is from another thread and shows the adjuster installed WRONG.

Image

This is a pic of my engine that I took while it was on the engine stand. I didn't know about the tensioner deal at the time and didn't know to check. The picture is dark, but if you look carefully you can see what looks like the end of the tensioner. About 9 o'clock, just above the gear and below the bolt at 10 o'clock.

Image

How much tear down is involved to get the tensioner where it belongs?


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