Oozing oil through the head gasket, re tighten the bolts?

jurgenkoppen

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Gentlemen, is it normal for the large cylinder bolts to come loose over time? My 79 started oozing a bit, fine oil mist all over my side cover. I tightened the outer bolts a bit, but then remembered your sage advice to read or ask before jumping in. Other than this messy mist, she still goes like stink and starts easy. Appreciate all and any advice.Cheers, J
 
If you still have the original rubber washers under the 4 outside acorn nuts then yes, it's very common for them to keep coming loose.
 
Oh no, I did the wrong thing then today. I went through the proper sequence with Torq wrench, they were all very close to spec. Test drive, came back with more oil than before from the head gasket down. Who would have guessed it is such a finicky process ...And how screwed am I exactly?
 
Pretty well covered that one Gaz, re torque of head bolts is a must and anti seize on the nuts and studs does make a difference. I've had to do mine, guilty as charged for not adding anti seize in the first place. The head bolts did seem really tight when I did re torque, but once cracked the readings were lower. That's when the light bulb moment happened....
 
Oh no, I did the wrong thing then today. I went through the proper sequence with Torq wrench, they were all very close to spec. Test drive, came back with more oil than before from the head gasket down. Who would have guessed it is such a finicky process ...And how screwed am I exactly?
No problem just go back and do it the right way, it either works or
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OK, so I take them off one after the other, lube each and retorque. How essential are the copper washers, should I delay until I can order and receive them?
I still have the original washers on. Some here said I must replace those washers if I loosen or undo to lube. Is that so?
 
Well some on here swear the washer change out is a must do. I have never used anything but the stock rubber washers, I have done at least 7-8 retorques the ones that live here are dry and have stayed that way. YMMV.
 
^The stock washers were the best thing for the job, or they would have used something else instead. They probably have the effect of locking the nut somewhat.

My experience, and the experience of some others, is that the four outer nuts are always loose (regardless of washer type). The question is why, and would blue Locktite fix it -- or is the looseness due to the stud stretching or the gaskets compressing. BTW, one interesting thing to look for is when you go much past 27 ft.lbs., release the torque slowly and you can watch the nut turn ccw because the last bit was the stud twisting.
 
BTW, one interesting thing to look for is when you go much past 27 ft.lbs., release the torque slowly and you can watch the nut turn ccw because the last bit was the stud twisting.
OK, that is a bit cryptic....Do you mean to say that when I let off on my torque the nut will turn ccw without me turning it that way....because the bolt has been twisted internally and stretches itself back to its original pristine condition?
So hoping that my head can stay on. I do not mind some light hearted wrenching, but head removal is not what I signed up for when I torqued the nuts..
 
I can't say I've ever noticed that happen but then again, I wasn't looking for it. You don't have to remove each nut/bolt and lube it but you should at least crack each one loose before re-torquing. Being on there so long undisturbed, they can get stuck on the threads and give a false torque reading. In other words, they may seem tight when they're really not.

The only bolts/nuts you need be concerned with are the 8 big acorns on top and the 2 bolts below the spark plugs. These 10 fasteners are the ones that compress the head gasket. The other M8 bolts on top just hold the top cover on and don't apply any force to the head gasket. There is one more head gasket bolt, a little M6 on the back down in between the carbs, but it's very hard to get to. It is loose many times but doesn't seem to contribute much to head gasket leaks. Tighten it if you can but don't worry too much if you can't.
 
It is loose many times but doesn't seem to contribute much to head gasket leaks. Tighten it if you can but don't worry too much if you can't.
Yes, I noticed that lil fellow as being obstinate, and approaching it was daunting . Do you gurus take of the air intake manifold which is obstructing it, to get there with your sockets? It seems impossible to get a torque wrench attached even with a wide range of extensions and knuckles on the socket...
 
^The stock washers were the best thing for the job, or they would have used something else instead. They probably have the effect of locking the nut somewhat. - - -

Hi xj,
gawd! You'll be thinking that politicians tell the truth, next.
those 4 washers are to seal those 4 studs so oil won't leak out of them.
Alas that Yamaha used the wrong washer design that has a rubber seal bonded to one surface like a plain washer.
This washer design lets the rubber squish as the nut gets torqued so those nuts lose torque over time.
What they should have used is Dowty washers. What most folks do instead is use solid copper washers.
 
Honestly, I don't usually bother with that one, and if I do, it's just by getting any sort of wrench or socket on it and hand tightening (no torque wrench). M6 fasteners abound on bikes and after tightening literally hundreds of them over the years, you kinda develop a "feel" for what's right.
 
Hi xj,
gawd! You'll be thinking that politicians tell the truth, next.
those 4 washers are to seal those 4 studs so oil won't leak out of them.
Alas that Yamaha used the wrong washer design that has a rubber seal bonded to one surface like a plain washer.
This washer design lets the rubber squish as the nut gets torqued so those nuts lose torque over time.
What they should have used is Dowty washers. What most folks do instead is use solid copper washers.
Yo Fred, I share your doubts in politician's offgassing, and also duly take note that a system which requires such frequent retorquing might not be quite at the height of its evolution in design. So I am keenly interested in your pointing. Would you care to elaborate, as to more detail and function of your solution, as well as availability. Or should I just google it and expose myeself to further misinformation?
 
Also, Master Fred remaining in toon, I noticed in your bike blurb that you use xs11 bars. So you are pointing to the little engine guards on a Standard, and are saying they will fit on my 78 650? That would be greats, because since I installed my Delcevic SS pipes, my previous bars are useless now. And my driveway from hell does make roll bars manditory.
 
Most of us just use copper or brass washers, soft enough to seal the oil in but hard enough to hold the nut's torque. Many other bikes flow oil through some of their engine studs like the 650 does. None that I know of use a rubber/metal sealing washer, they use copper. In fact, the replacement many of us use comes from the big GS Suzuki fours.
 
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