G5 head o rings

[twodogs]

Hi all, say I have 4 little o rings and 1 big one I want to replace on the left head, is the big one under the plug? Plus are the smaller ones under the rocker assembly ? Do I have to remove the assembly to get to those, I have oil around the bottom of the head and on top of the cylinder all the way around and was told that if the o rings are bad it will seap around there, I'm no wrench but I'm going to give it a go. Thanks for info.
Bruce

[Antietam Classic Cycle]

Yes, the small ones go on the long studs, between the head and rocker support. The larger one seals the cover plug.

Chances are that you may "break the seal" of the base gasket while replacing those cylinder studs o-rings and end up with another leak unless you replace the base gasket and the two o-rings on the short studs. .

[twodogs]

Thanks Charlie, I thought about that, I have a head gasket but no base, I think I'll just retorque the head and clean it up and see what happens, do I break 1 at a time then torque it back down?
Bruce

[Antietam Classic Cycle]

Thanks Charlie, I thought about that, I have a head gasket but no base, I think I'll just retorque the head and clean it up and see what happens, do I break 1 at a time then torque it back down?
Bruce

I do. Just back each one off enough to break the "stiction", then torque to 32 ft. lbs. That cover plug o-ring can be a source of leakage, so definitely replace that.

[pehayes]

Thanks Charlie, I thought about that, I have a head gasket but no base, I think I'll just retorque the head and clean it up and see what happens, do I break 1 at a time then torque it back down?
Bruce

The MOST COMMON source of head leakage is from the larger o-ring under the inspection bolt head for the top-center head bolt.  If that o-ring hasn't been changed in awhile I would start there and then see if the leakage continues before going into the stud o-rings.

Patrick Hayes
Fremont CA

[twodogs]

There was a metal washer in the inspection bolt recess and no rubber o ring  so I just retorqued the top center allen bolt and replaced the inspection cover, does the o ring go over that metal washer? Thanks guys.
Bruce

[Antietam Classic Cycle]

There was a metal washer in the inspection bolt recess and no rubber o ring  so I just retorqued the top center allen bolt and replaced the inspection cover, does the o ring go over that metal washer? Thanks guys.
Bruce

No "metal washer" under that cover plug (except on older Guzzi with a 26 mm hex head cover plug). There is a washer under the "allen bolt" though. Just an o-ring in the provided recess. #13 is the cover plug and #14 is the o-ring, #15 is the "allen bolt" and #16 the washer:

[pehayes]

There was a design change.  In the early round heads, the top-center access plug was a large (27mm?) external hex head with an aluminum crush washer below.  The later design was a cap with a 10mm Allen recess.  Under this head there was a groove to accept an o-ring.  You should never have BOTH a crush washer and an o-ring.  One or the other.  The older crush washer version could be augmented with a little gasket cement.  The latter o-ring version just requires periodic replacement of the o-ring due to crush and heat.  Typically gets hard as a rock.

Patrick Hayes
Fremont CA

[twodogs]

Well thanks guys, I took the plug out and took what I thought was a metal washer out of the recess in the plug, tomorrow I'll take it back out and see if it is metal or just a rock hard piece of o ring, what I'm wondering about is under that plug where it is open to the head bolt there is no signs of oil leaking under the inspection plug, I'll try again tomorrow and try to take a pic, when I broke loose the head bolts to retorque em they did not seem to be very tight, wish I was better at this. LOL.
Bruce

[pehayes]

Well thanks guys, I took the plug out and took what I thought was a metal washer out of the recess in the plug,

Bingo!  The older hex head with crush washer is a simple bolt head with no recess.  If you found a recess under an Allen hex head then that is the designed location for an o-ring.  If you thought it was metal, that is just an indicator of how hard the things can get. 

Patrick Hayes
Fremont CA

[twodogs]

Winner winner Patrick, the o ring was hard as a washer so I replaced it with the o ring then torqued the head and went and done the other side, I cleaned the wires per Chuck's great pics on his g5, now I'm changing the fluids and replacing the fuel taps on the gas tank and then check out the brake pads, once again thanks for the help.
Bruce

[F-22]

(27mm?)

I think it is 26mm, I remember I turned my workshop upside down until I found a wrench for it (most standard socket sets go from 24 or 25mm to 27mm, without 26).