honda305 Home honda305 Auctions honda305 Gallery honda305 Forum


honda305.com Forum

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

engine blowby

Post Reply
User avatar
davomoto
honda305.com Member
Posts: 2508
Joined: Sat Nov 18, 2006 7:36 pm
Location: Marin County CA

Post by davomoto » Thu Sep 23, 2010 7:13 pm

Happy to help!
davomoto
64 CB77
63-7 CB77 Cafe'
67 CL77
64 CL72
66 CL77 big bore flat tracker
Many others!

mike1969
honda305.com Member
Posts: 720
Joined: Sat Feb 06, 2010 6:53 pm
Location: w.pa.

blowby

Post by mike1969 » Sun Sep 26, 2010 11:55 am

Got the motor assembled and back on the bike. I'm happy to say that the blowby is gone!

Thanks to everyone who helped with advice.

I still have to re-torque the head bolts.(thanks for that tip also)

mike1969
honda305.com Member
Posts: 720
Joined: Sat Feb 06, 2010 6:53 pm
Location: w.pa.

blowby

Post by mike1969 » Sun Oct 10, 2010 12:05 pm

Sonofabitch! I thought all was well with the Dream. I took it on an extended ride this
morning and the blowby is back with a vengence!

I can feel air blowing from the crankcase vent hose from 5 inches away at idle.

Everything is back together correctly(rings etc.)

Is there a possibility that the oil pump is putting out too much pressure?

User avatar
davomoto
honda305.com Member
Posts: 2508
Joined: Sat Nov 18, 2006 7:36 pm
Location: Marin County CA

Post by davomoto » Sun Oct 10, 2010 8:45 pm

Mike, no these oil pums have minimal pressure.

Davo
davomoto
64 CB77
63-7 CB77 Cafe'
67 CL77
64 CL72
66 CL77 big bore flat tracker
Many others!

mike1969
honda305.com Member
Posts: 720
Joined: Sat Feb 06, 2010 6:53 pm
Location: w.pa.

blowby

Post by mike1969 » Mon Oct 11, 2010 6:53 am

Thanks Dave,That eliminates another possibility.

Any suggestions?

LOUD MOUSE
honda305.com Member
Posts: 7817
Joined: Mon Aug 15, 2005 8:23 am
Location: KERRVILLE, TEXAS

Re: blowby

Post by LOUD MOUSE » Mon Oct 11, 2010 7:21 am

Ya did install the 2 gaskets and metal plate at the top?. ............lm

mike1969 wrote:Thanks Dave,That eliminates another possibility.

Any suggestions?

User avatar
Snakeoil
honda305.com Member
Posts: 1150
Joined: Wed Aug 04, 2010 6:45 pm
Location: Upstate NY

Post by Snakeoil » Mon Oct 11, 2010 8:45 am

I would expect there to be significant air flow out the breather hose of a running engine. The crankcase is a sealed vessel of varying volume, and breaths thru that hose. No flow thru that hose means you have a hole in your crankcase somewhere. If there is no smoke coming out of the hose and your compression test is to spec, I would think you are good to go.
regards,
Rob

Post Reply




 

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