1981 Honda CB650C Clutch Rattle

If it's broken or just needs tweaked

Moderators: Volker_P, tidd650

User avatar
Whacky Wheels
Posts: 7
Joined: Sat Nov 25, 2017 4:07 pm

1981 Honda CB650C Clutch Rattle

Postby Whacky Wheels » Sun Dec 03, 2017 4:51 am

Hi guys! So this is my first post on this website, I do apologise if there has already been a thread opened for this topic, but I am wondering if anybody has had a similiar problem:

Upon startup and low revs, there is an immense rattle that sounds like it is coming from the the clutch, but when I pull the clutch lever in, or when I put the bike in gear and start riding, the rattle suddenly disappears. Does anyone perhaps have any advice on this? I bought the bike second hand from a shop here in the Cape Town area in South Africa. (Also live in SA). I have a vague suspicion it is the carbs that are not synced properly, but some advice would be great thanks!

Some details about the bike: 1981 Honda CB650, 53 000km on the clock, looks as original as can come except for a view paint changes! Still has original frame stickers for chain slack and tire pressure.

Thanks in advance!

User avatar
Folsoml
Posts: 1634
Joined: Sat Apr 07, 2012 9:02 pm
Location: North Florida

Re: 1981 Honda CB650C Clutch Rattle

Postby Folsoml » Sun Dec 03, 2017 8:43 am

Welcome to the forum!

Your clutch dampers may need replacing. Here is a link to a tutorial on replacing them. The tutorial is for a CB900C, but the procedure is the same:

http://www.cb750c.com/modules.php?name= ... ic&t=23512
Have a problem with your CB650? Have a technical question? Click here!


My Current Bikes: 2005 HD FLHTCUI Electra Glide Ultra Classic, 2007 Yamaha Vino,

cb650
Posts: 2959
Joined: Fri Mar 03, 2006 7:20 am
Location: Denver CO USA
Contact:

Re: 1981 Honda CB650C Clutch Rattle

Postby cb650 » Sun Dec 03, 2017 11:11 am

Try adjusting it and if it works properly and idles smooth just run it. The 650 clutches do make some noise anyway.
Did you clean the tank out?!?!?!?!

Ox Moto
Posts: 6
Joined: Mon Dec 04, 2017 8:29 am

Re: 1981 Honda CB650C Clutch Rattle

Postby Ox Moto » Mon Dec 04, 2017 8:30 am

Also best to open up that cover
Sometimes things come loose
Or break off

Sent from my SM-G870W using Tapatalk

User avatar
Whacky Wheels
Posts: 7
Joined: Sat Nov 25, 2017 4:07 pm

Re: 1981 Honda CB650C Clutch Rattle

Postby Whacky Wheels » Wed Jan 17, 2018 3:55 am

HI guys! Thank you so much for your replies, sorry that I dissapeared. Work became hectic. I opened up the clutch and found everything to be in order. Turns out it was the carbs, the main jets (4 of them), were odd: 3 were the same and original, 1 was odd. So the cylinders fired differently with every revolution. Thanks again!!

User avatar
Folsoml
Posts: 1634
Joined: Sat Apr 07, 2012 9:02 pm
Location: North Florida

Re: 1981 Honda CB650C Clutch Rattle

Postby Folsoml » Wed Jan 17, 2018 6:24 am

Whacky Wheels wrote:HI guys! Thank you so much for your replies, sorry that I dissapeared. Work became hectic. I opened up the clutch and found everything to be in order. Turns out it was the carbs, the main jets (4 of them), were odd: 3 were the same and original, 1 was odd. So the cylinders fired differently with every revolution. Thanks again!!


Now you have my curiosity wanting to know what was "odd."
Have a problem with your CB650? Have a technical question? Click here!


My Current Bikes: 2005 HD FLHTCUI Electra Glide Ultra Classic, 2007 Yamaha Vino,

User avatar
Whacky Wheels
Posts: 7
Joined: Sat Nov 25, 2017 4:07 pm

Re: 1981 Honda CB650C Clutch Rattle

Postby Whacky Wheels » Tue Dec 31, 2019 2:39 am

Folsoml wrote:
Whacky Wheels wrote:HI guys! Thank you so much for your replies, sorry that I dissapeared. Work became hectic. I opened up the clutch and found everything to be in order. Turns out it was the carbs, the main jets (4 of them), were odd: 3 were the same and original, 1 was odd. So the cylinders fired differently with every revolution. Thanks again!!


Now you have my curiosity wanting to know what was "odd."


I actually sourced another set of carbs, but the original ones had different size jets in the each of the 4 carbs. And they were filed down to different lengths with a metal file and the brass shavings where just lying in the carb bowls!! Can you believe it. Have stripped the engine since then, as I have zero trust in the previous mechanical work on this engine.


Return to “Technical Discussion”

Who is online

Users browsing this forum: Google [Bot] and 36 guests