How to know if copper head gasket worn out?

While putting off facing another set back in simple Cdo maintenance, like sealing, I think Trixie's copper gasket got re-used once or twice too much. She mostly apart now to re-seal [eventually] from ring blow by event last year but still blew oil out head seam and barrel base and crankcase seams. I expected head leak to be between gasket and thermal changing Al head but that surface was fine and oil dry but oil wetness and dark areas on gasket imply that's where it got beaten by vibes or gas jet leaks. This gasket has been though like 6 head removals over last 6 yrs. Bad experience of flamering prior years prevented me from trying the new on on shed wall till now. Gasket is now work hardened copper stiff but was wax like soft floppy after bright orange annealing so handled very carefully > supported more like big pancake must be. Could not even hang by a inner edge so soft it would distort whole gasket and skew the big holes out of round but got it on barral undistrube good fit around bores and free piston passage. I think there's un- evenness of its thickeness now so no amount of annealing will squeeze down to seal anymore. I've seen gas jet erosion in head seam surfaces prior but there is no evidence of that taking copper with it in Trixie's case. For perspective of frustration and depth of my inquiry, ...
Trixie did not leak or weep any oil IF I only used light throttle and only went 10 mph over 55 hwy limit. I had head fasteners so tight I had to use hammer on wrench carefull not to distort wrench to break free. Not to worry I'll make sure they are about that tight again. As I'll likely miss another year of no Commando I might as well spend some bux and get the pressure measuring test sheet in big enough size to cover the head area and see for sure about torque use.

hobot said:

........ This gasket has been though like 6 head removals over last 6 yrs.......

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Not sure how many times one can be re-used, suspect each person/application is different, might want to a fiber one again Steve.

Thanks cj, its just me crying in my milk as only way to know is when they fail to seal. I've got a flamering type new in package on shed wall I've resisted trying again till now. We do not hear of racers using flamerings so I may find out why. I ran Trixie to full HELD WOT for dozens of miles a go about 6 times a couple years ago and she held up fine no leaks. I am fully aware of her power and handling limits so much so I've no desire to ever press Trixie much again. For me its been Wrench a lot to ride a bit to wrench a lot more again though no fault of my own so far on Trixie. Posting here is just an excuse not to dig in to next hang up I'll have to re-do again, like push rod binding on her TS - 'need' to suck out horrific tight spindle again to fix the rockers as easy as the other side works. I'll cheat on head gasket with Hylmar smear and organic thread or copper wire around everything.

Steve I've never had issues with head gaskets copper properly annealed and re-used WITH a light smear of the mind-numbingly wonderful Permatex Ultra Copper over mating surfaces. This is the same product for exhaust nuts threads which have never backed off ever. I do not lead you astray on this but am contemplating buying stock in the company. Holy cow. Great ride today. :roll:

Ugh I used the copper spray last time but for some reason its not enough anymore. In the end what I'm actually upset about is only reason for resealing is because I'm just a posser at heart that can't drive just 55, 20-50 miles and not want to wash off before stops in biker towns that CDo's close looks reflects on 1st impressions of me. When I stop to gas up at biker crowded station the owner or cashier will routinely tell its a smart looking cycle, but I know if wasn't cleanish shiny it'd look so long in tooth uncared for they'd keep their opinion to themselves. Rest of yoose guys may leak so much to need fix but for Trixie its pure cosmetic decision not to ride her this year and only so much time left, ugh- actually it was a show stopping leak from primary case bolt backed out that got me started on reseal, then the kick starter failed in garage after sealing that back so opened gear box to see damaged ratchet stop so no fast solution to get back on road with many other priorities in the way of mere pleasure craft.

me thinks you have used your head gasket once too often. Have I heard you say you use a torque wrench then wind the snot out of things again. You mentioned how tight the nuts/bolts were to undo. Naughty Naughty. The manual gives you the correct torque settings for a reason. Have you warped your head now. Is it bent around every stud hole. The only way you can squash you gasket is but winding the snot out of those bolts/nuts. Too tight is broken with Japanese stuff you know. Or there may be something in the fact that you may be able to over anneal the copper. Not a scientist here so cant say. Those are all possibilities, but when we talk about using head gaskets again, we usually think in terms of the second time, not 6-8 times. I would say that that copper has had its day.
Dereck

PS stick with what you know. you have had great success with the copper gaskets so keep using them. No sure about that other thing you mentioned. Next time get 2 copper gaskets then you will have a spare. Put a micrometre on that old gasket and tell us what has happened to it.

Yeah just micrometer it and compare. Never heard of a warped head, That's early Triumph talk. :|

kerinorton said:

me thinks you have used your head gasket once too often ... when we talk about using head gaskets again, we usually think in terms of the second time, not 6-8 times. I would say that that copper has had its day.
Dereck.

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Yes. I have used them say four times but then I hit trouble. A nice new one, carefully fettled around the pushrod tunnels and copper spray and all was good again.

Hm, 4 times agree's with what I experienced with Trixie, that stayed sealed after same copper gasket installed 4x's d/t various other major lets goes - then air boot cracks rings blew past it the 5th time but held till I got on Combat 2S cam somewhat over a few 100 miles- then began to leak so lifted head and smeared some Hylomar on 6th torque down but leaked if operating beyond sedate legal gramma style.

I did suspect my OVER torquing might of distorted head and fully expected to find leak evidence on head side but found it instead on the barrel side, so I'm sticking to my OVER torque that held up in Peel OVER rev event and a few of Trixies engine blow ups form taboo piston + Al gasket and later rod bolt fail. Wes is who taught me to OVER torque as shocked at 1st watching him and then trying to help undo his head once, d/t his rings eaten up after k/n filter on his Miki carb install. Wes didn't believe me about the k/n filter till it eat another set of rings up in less than a year, so now wears the foam wrap around that was on Ms Peel's Miki carb. Wes has had to modify-beef up his Suzuki scooter filter too as it ate its rings up too soon too.

I'm still hesitant to try another flamering of questionable quality this last decade so thinking to shorten push rods and go w/o a gasket and see what happens. Last one blew in 1st 10 miles of easy commuting throttle and for sure was not d/t lack of enough initial torque.

Hobot.....we are talking a $30 to $40 gasket here......are you serious? when you talk spark plugs you always say buy the V8 pack!

I just bought 2 from JSM and one from Maney....so I have an unsquashed ebay one you can have for international shipping! :?

I don't think they wear out, they just fail.

Steve I just didn't know better on how many times I could get re-use a .040" copper gasket and thought after 4 successes the 'over' annealing would work a few more times. So I got to repeat the prior trial/errors of more seasoned Nortoneers like you. I've had 3 thickness of JSM gaskets sent to Canaga last season and few other Peel item$ on top of major uexpected money hits so trying to keep some flow going down the Norton drain.

Pete I think you pretty much nailed it, they just get worse and worse till finally can't stand it. I'll armor the fuel hoses for next 'long term' flamering test, last one blew straight out the oil drain hole on rear Rh letting combustion jets out a few inches but strangely nil smoke to concern me till reviewing old posts as mood sunk remembered some mentioning concerns of fuel hose risk so close to engine, THEN EYES WIDENED to pull over literally in paper thin hose nick of time.

FWIW and my education, I measured 4 copper 750 head gaskets.
The difference between new and used was negligible; measurements were 0.039-0.041".
Seems like there was no reduction in thickness due to previous use/torquing.

I did not realize that new copper was getting so expensive!

Its not the expense as hassle of ordering and waiting again. I think Trixie's gasket issue is areas of it vary now from ~.039 to .41" thickness regardless of the clamp force. I'll ask Wes how many times his '71 reused a copper gasket. I've not had any machine work done on head or barrel surfaces and they sealed fine on fully testing Trixie Combat front lifting 2S cam power peaks and over 100 mph for dozens of miles tagging along with maxed out elite exocta enjoying no police swoopy sweeping Ozarks. Flame ring slightly ups the CR so may lug grunt around a bit better as no desire to max out Trixie for some years now. Got old car back on road today so extra energy to get more of Trixie dissected. Let ya know if i figure out the TS pushrod puzzle or just refine the accidental stuck pushrod ejection revelation in reverse.

Bob Z. said:

FWIW and my education, I measured 4 copper 750 head gaskets.
The difference between new and used was negligible; measurements were 0.039-0.041".
Seems like there was no reduction in thickness due to previous use/torquing.

I did not realize that new copper was getting so expensive!

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Without wishing to make a big thing of this-

I used copper gaskets on my race bike - not my street bike. This is mainly because you can torque them down and race on just one retorque cooling cycle. Composite gaskets need careful heating and cooling and retorquing a few times in my experience before going all out. You usually dont have the time to do this with a race bike - especially half way through a meeting.

The copper gaskets dont really " wear out" or get too thin in my experience. They just distort and expand away from the studs, barrel flange and pushrod tunnels. So after a while you get this poorly fitting gasket which leaks.

So thats why I replace after maybe 4 cycles. I have a packet of about 6 gaskets in my spares box and just grab a new one when I need it.

For me they are a consumable just like having a few oil filters in your spares box.

johnm - some of us non racers really don't expect to open up 4 times over a short life time to need a spare gasket of any type, but some of us do. Ironic event yesterday on stocking spares, my lap top charge wire snagged Peel's front fender, moved d/t wife plants coming in, so jerked out hands ruining it. Now must get another spare fender and laptop. In rural area like here winter slow down means ya need some extra nut$ and stacked wood ahead of time.

hobot said:

johnm - some of us non racers really don't expect to open up 4 times over a short life time to need a spare gasket of any type, but some of us do. Ironic event yesterday on stocking spares, my lap top charge wire snagged Peel's front fender, moved d/t wife plants coming in, so jerked out hands ruining it. Now must get another spare fender and laptop. In rural area like here winter slow down means ya need some extra nut$ and stacked wood ahead of time.

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" my lap top charge wire snagged Peel's front fender, moved d/t wife plants coming in, so jerked out hands ruining it. Now must get another spare fender and laptop. "

Thats not good !!

Yes when you go racing you seem to build up a fair piles of spares. My magneto and carb jets and spares box would be expensive to replicate!

Half the reason I'm online is for the therapy by others let downs so I don't take it so personal to blow up hurting me & people/animals/things around me. I've collected enough parts to fix Trixie w/o more vendor spending, as trying to reduce Commando spares piling up. Leave now - rest is just bad karma luck outs.

Yesterday getting a non-vital car part got an uplift + mood drop equalizer hearing a customer entering door telling the staff, "if it ain't one thing its another, now the water %^& pump went out... Lost a '96 Oldsmobile engine last month in Oklahoma and had big parts switched to 'new' '93 Olds, watching my mechanic leave blood and skin over blocked frame impossible fastener access - while mechanic next stall over with a '68 Corvette discover after front end & delicate hood back on - he'd put a/c drier unit backwards. My 'new' '93 cream puff 67K mile Cutlass siezed in 2000 miles but found a good used engine sent from Fla, should of been back a week ago but their praised best mechanic nicked the Al radiator just before start up...
In spring almost got mower about to start to discover governor gizmo fell apart so lost heart to redo everything with Trixie waiting in the wings. Got a neat little mini pit bike and invented compact frame carrier for it on car trailer hitch by itself or on trailer front when towing - checked its hose clamp frame mount regularly > fine till 1 mile from home - finally retrieving form 250 mile away - THE Gravel beat it loose so mini fell off mangling front fender, ugh. Lucked out '93 Olds siezed close to home so got friends to trailer it to shop in same day of lost time.

I'm replacing this one with a new one.



Ken

Hm, somewhat similar to Trixie's leaker but your shading contrasts are rather more dramatic looking. What do the bright and dark areas indicate, besides oxidized or not, beaten or eaten away? Did it leak to matter?