Hey! All the Techs out there...

Working on a 2007 1200 Sportster...Head gaskets have blown on me twice - Cylinder/Heads are not warped. Using factory head gaskets. Gaskets are blowing on left side "small bolt" side. Im begining to think the Cylinder studs & head bolts are weakening on me. When installed i can slighty see a gap which i know is no go from the begining - installing the heads correctly is being accomplished same with removing them.

Just wanted to get some more insight on the possibilites of having stretched studs? Its looking to be my last option. Any tech help would be much appreciated. Thanks

 

Doubt if the studs are fubar'ed.
We use Cometic MLS EST gaskets here, set at 10, 20, then 90 degree bolt turn. (comes in at about 42 ft/lbs.)
NEVER have we experienced cylinder head gasket failure via the gasket, or method described, even on 124's-131's at 11.0-11.5 cr.
Scott

 

O ok cool deal thanks for the info on the gaskets ill check them out - Should i maybe replace the head bolts? It was just strange to see the head not even flush with cylinder after everything was torqued properly. I have a service manual so i did sequence right. By saying set a 10/20 u meaning ft lbs? Should i lube the studs with a small amount of oil?

 

Should i be concerned with the dowel pins rubber o-rings?

 

No need for bolt replacement either.
Yes 10, 20 are ft/lbs.
A dot of lube is always a good idea, as better accuracy will occur.
Scott

 

Ok awesome thanks a lot for the info.

 

Happy to lend a hand.
Scott