honda305 Home honda305 Auctions honda305 Gallery honda305 Forum


honda305.com Forum

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

CB72 compression - what are GOOD readings?

Post Reply
bbraun
honda305.com Member
Posts: 42
Joined: Mon Jun 25, 2007 2:55 pm
Location: CT

CB72 compression - what are GOOD readings?

Post by bbraun » Tue Sep 18, 2012 4:04 pm

What would be considered good compression on a CB72? I could tell mine is tired but I've been putting off a motor rebuild. L. is 100 and R. is 120 using the kind of weak battery/starter in it.

Thanks
Beth

'64 CB72
'64 CB77/Yetman race bike
'65 CA77
'63 CA72 project
'65 CB160 race bike

'63 CA95

a number of other '60s Hondas

User avatar
brewsky
honda305.com Member
Posts: 1816
Joined: Wed Jul 23, 2008 5:21 am
Location: Princeton, WV

Post by brewsky » Wed Sep 19, 2012 4:25 am

That is plenty especially if the readings are cold.

I believe the spec is 120 psi for a c72.

Check when warmed up, throttle held open, choke off, good battery or several kicks.

Readings could be a little closer.
66 dream, 78 cb750k, 02fz1, 09 wing

bbraun
honda305.com Member
Posts: 42
Joined: Mon Jun 25, 2007 2:55 pm
Location: CT

Post by bbraun » Wed Sep 19, 2012 6:27 pm

brewsky wrote:That is plenty especially if the readings are cold.

I believe the spec is 120 psi for a c72.

Check when warmed up, throttle held open, choke off, good battery or several kicks.

Readings could be a little closer.

A C72 is a 250 Dream. A CB72 (Hawk) compression certainly should be more.
Thanks for checking though -
Beth

'64 CB72
'64 CB77/Yetman race bike
'65 CA77
'63 CA72 project
'65 CB160 race bike

'63 CA95

a number of other '60s Hondas

User avatar
brewsky
honda305.com Member
Posts: 1816
Joined: Wed Jul 23, 2008 5:21 am
Location: Princeton, WV

Post by brewsky » Wed Sep 19, 2012 8:02 pm

Sorry...I misread the model.
Still wouldn't be worried about those numbers unless they are warmed up and consistently that much different.
66 dream, 78 cb750k, 02fz1, 09 wing

Post Reply
cron




 

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