honda305 Home honda305 Auctions honda305 Gallery honda305 Forum


honda305.com Forum

Login
□ Search
□ FAQ 
□ 
Vintage Honda Owners,
Restorers, Riders and
Admirers

CL72 high rpm issue

mike in idaho
honda305.com Member
Posts: 411
Joined: Sun Jan 29, 2012 9:18 pm
Location: orofino, idaho

Post by mike in idaho » Thu Jul 04, 2013 4:07 pm

Does it have stock gearing? Do you know how many rpm it's turning when it quits?
'65 YG1
'65 CB160
'66 CL160
'66 CL77
'78 XS650
'79 GL1000
'69 T100R
'68 TR6
'69 T120
'72 750 Commando
my company car is a Kenworth

qwerty
honda305.com Member
Posts: 39
Joined: Mon Apr 08, 2013 11:07 pm
Location: Mill Valley, CA

Post by qwerty » Thu Jul 04, 2013 6:25 pm

Mike,

I'm not sure about the gearing or specifically how many rpms it reaches before it sputters. Is there an easy way to check either of these things?

Thanks,
Graham

mike in idaho
honda305.com Member
Posts: 411
Joined: Sun Jan 29, 2012 9:18 pm
Location: orofino, idaho

Post by mike in idaho » Thu Jul 04, 2013 6:57 pm

Count the teeth on the sprockets. Should be 15 teeth on the front one and 40 teeth on the rear.
'65 YG1
'65 CB160
'66 CL160
'66 CL77
'78 XS650
'79 GL1000
'69 T100R
'68 TR6
'69 T120
'72 750 Commando
my company car is a Kenworth

jensey
honda305.com Member
Posts: 384
Joined: Sun Jun 17, 2012 3:34 am
Location: Netherlands

Post by jensey » Fri Jul 05, 2013 12:38 am

Hi,
I'm not sure about the gearing or specifically how many rpms it reaches before it sputters
Is this sputtering regular or irregular ?

In most cases irregular sputtering issue's are correlated with the ignition, regular sputtering is often correlated to carb issue's. It's not a law, but certainly not coincidental.

Jensen
assembly of Japanese motorcycles requires great peace of mind (Pirsig)

qwerty
honda305.com Member
Posts: 39
Joined: Mon Apr 08, 2013 11:07 pm
Location: Mill Valley, CA

Post by qwerty » Fri Jul 05, 2013 12:43 pm

Mike - there's 37 teeth on the rear sprocket - would that be a possible cause of my issue?

Jensey - could you describe regular vs. irregular sputtering? Isn't sputtering irregular by definition?

Thank you both for helping me cover all bases!

Graham

qwerty
honda305.com Member
Posts: 39
Joined: Mon Apr 08, 2013 11:07 pm
Location: Mill Valley, CA

Update

Post by qwerty » Tue Jul 09, 2013 11:34 pm

I pulled the carbs and brought them over to Davo to look at and he helped point out a host of possible causes that might have caused problems ( thank you Davo - you are a river to your people) - I am now 99.9% sure it's carb related. Took the crusty filters off of the fuel line banjos, cleaned out all the vent holes in the carb, replaced the slow jets, etc. I put the carbs back on and had some backfiring on one side, so I'll pull that carb and check it again, but I'm optimistic....
Stay tuned...

jensey
honda305.com Member
Posts: 384
Joined: Sun Jun 17, 2012 3:34 am
Location: Netherlands

Post by jensey » Wed Jul 10, 2013 12:58 am

Hi,
Jensey - could you describe regular vs. irregular sputtering? Isn't sputtering irregular by definition?
regular sputtering means constant sputtering, at a certain rpm range it will sputter constantly, irregular sputtering at a certain rpm is like it sputters for a few seconds, then it pulls, sputters again, pulls, etc. But I admit, you have to hear it to recognize it.

For example, when the bike is warm, and you pull the choke a bit while riding it starts to sputter constantly, and will not stop sputtering as long you stay in a certain rpm range.

btw, my advice is to clean the carbs ultrasonic, works like a charm.

Jensen
assembly of Japanese motorcycles requires great peace of mind (Pirsig)

Post Reply




 

CB-77 | CYP-77 | Road Test | Riding Log | Literature | Zen | Marketplace | VJ Survey | Links | Home