honda305 Home honda305 Auctions honda305 Gallery honda305 Forum Forum

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

Cl77 piston to bore clearance

Post Reply
Beachwv Member
Posts: 5
Joined: Mon Feb 11, 2013 10:19 am
Location: West Virginia

Cl77 piston to bore clearance

Post by Beachwv » Sun Jun 07, 2020 8:27 am

Working on 1966 CL77 I just bought. It ran but smoked and leaked from seals. Pulled the engine and removed the topend. Bores are glazed with a bit of roughness from sitting. I know clearance should be .002 at skirt but wondered what max is for clearance. If its too close to max when clean I will go first oversize.
Thanks, Bill

Tim Miller Member
Posts: 242
Joined: Mon Jan 30, 2012 6:22 pm
Location: Pflugerville, TX

Re: Cl77 piston to bore clearance

Post by Tim Miller » Sun Jun 07, 2020 4:03 pm

Shop manual shows rebore limit at a loose.0039”. I would expect with that much ring end gap it would certainly start consuming some oil and possibly some piston slap noise. I go with .002 to .0025”.
Oh yeah and if your sleeves are loose in the cylinder that’s a problem for heat transfer.


Post Reply


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