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Yes if you can't remove; loosen and retighten don't forget tt snug up that lonely little 4mm (10mm head) back down above the cam chain tensioner. Probably no big deal if you don't remove the regular bolts, it's the long studs that want to twist instead of tighten.
Got everything antiseized and retorqued to 25 ft/lb for the first round this afternoon. Will let it set overnight and apply more torque tomorrow. There was some rubber gunk in some of those big 8 studs. Got'em shiney now. The back side of the big 8 was a little hard to get at. Was able to slip a gun bore cleaning brush between to get at them. Hope this works. Hope to finish at about 35 ft/lbs. Is that the max. recommended torque?
Jefft
Jefft
I wouldn't go right up to 35, try 30 first. If that doesn't fix it, go 32 then 35 if that doesn't work. 35 really is about the max you want to go and only if absolutely needed. I cured my original gasket of leaks with just the 30. The new aftermarket gasket I have now (Athena) eventually needed 35. I don't think it's as good a gasket as stock. Next time I think I'll use some other kind (O.E.M. or Vesrah).
When I tightened one of the now antiseized nuts up to 25 lb and then loosened it again and retorqued it, I didn't feel the rough metal to metal squeaking sound I had previously heard before the cleaning and antiseize treatment. The torquing seem much smoother.
jefft
jefft
That's why we recommend the anti seize. Hope it stops your leak, let us know how it goes?
I torque to 30, run it some and retorque to 33 and run it again. No leaks, I leave it at 33 but if it leaks I go 35.
Not sure if this is approved by those who know more about these engines.
Not sure if this is approved by those who know more about these engines.
The engine has been rebuilded by PO, but now I have a small leak at the right rear corner at the cylinder base. More like sweating, letting off tiny amount of oil. The other sides are completely dry, though.
May it help this kind of leak as well, you think?
Also the head gasket is sweating little too in some areas. Minor though. So i thought I would have a go...
(Just as information, compression rates is 150 lbs on both cylinders.) So no problem there...
May it help this kind of leak as well, you think?
Also the head gasket is sweating little too in some areas. Minor though. So i thought I would have a go...
(Just as information, compression rates is 150 lbs on both cylinders.) So no problem there...
Yes it is worth a try, and usually stops the leaks. A retorque of the cylinder studs is usually recommended for all overhauls after a few hundred miles.
Thanks!
Any new input on the new higher torque setting recommendation for the big nuts?
I didn't understand if it was yamaha that recommended higher torque on the bigger nuts or other owners that have tried it and found it work better...
Any new input on the new higher torque setting recommendation for the big nuts?
I didn't understand if it was yamaha that recommended higher torque on the bigger nuts or other owners that have tried it and found it work better...
The higher torques is a member thing, It's hard to get a torque wrench on the inner ones so that is usually an arm gauge thing. I use about 30 foot pounds, shrug. Yes check all the bolts loosen then re-torque one at a time. Don't forget to check that little 10 mm bolt head back above the cam chain tensioner, that little bolt has to help seal about 4" of thin head gasket around the back of the cam chain tunnel and check the two 12mm bolt heads under the spark plugs.
Get the tank and top engine mount off and do them all, total time will be well under an hour. This is SOP for every engine I touch now.
This has never made sense to me:
According to the manuals, the head bolt loosening sequence is exactly the same as the tightening sequence. Shouldn't the last bolt tightened be the first bolt loosened? Shouldn't removal be the reverse of installation? Isn't that how automobile heads are tightened and loosened?
According to the manuals, the head bolt loosening sequence is exactly the same as the tightening sequence. Shouldn't the last bolt tightened be the first bolt loosened? Shouldn't removal be the reverse of installation? Isn't that how automobile heads are tightened and loosened?
yeah but.... We are not removing the head in this thread. My take has been on old engines loosen and retorque one bolt at a time. For a recent overhaul, you would just recheck torque not loosen. Unless the head is coming off I would not loosen them all at once. Any other opinions on that? A generally used tightening sequence is start in the middle work out progressively in a spiral. I seriously doubt any engineering studies have been done to arrive at a specific sequence, at least on XS650s. It's one of those things where it would be poor technique to start at the outside and work in, well, just because it seems so wrong.... On a fresh install you might have excess gasket get trapped in the middle somehow, but that would not be an issue with a retorque, would it?
If it is an error, it is a persistent one.
Both the Haynes and Clymer manuals have it.
The combined 1970-1974 factory manual has it.
The XS650E factory manual has it.
The only other manual I have is the XS650SJ-SK factory manual. It just says:
"Remove four cylinder head holding bolts, three cylinder head holding bolts and eight cylinder head holding nuts."
without giving any further specifics.
I know these heads are seemingly indestructible, and you never hear of them getting damaged due to improper installation or removal, but from now on, I'm going to reverse the sequence in the drawings when I disassemble, unless someone convinces me otherwise.
Both the Haynes and Clymer manuals have it.
The combined 1970-1974 factory manual has it.
The XS650E factory manual has it.
The only other manual I have is the XS650SJ-SK factory manual. It just says:
"Remove four cylinder head holding bolts, three cylinder head holding bolts and eight cylinder head holding nuts."
without giving any further specifics.
I know these heads are seemingly indestructible, and you never hear of them getting damaged due to improper installation or removal, but from now on, I'm going to reverse the sequence in the drawings when I disassemble, unless someone convinces me otherwise.
gggGary, I don't know, but I like to loosen them all, and then tighten them all, tightening them a little bit at a time in sequence, just like during a build.
I doubt that it makes much difference either way, except that doing them one at a time would be a lot lot faster since you tighten each bolt once, instead of in several increments.
I doubt that it makes much difference either way, except that doing them one at a time would be a lot lot faster since you tighten each bolt once, instead of in several increments.
Ok I think there's one reason anyways NOT to loosen them all at once. At least one valve is always open that spring is attempting to lift the rocker and the head cover, you loosen all the bolts and the head cover could separate from the head. So I don't think it's worth the risk. This might be splitting hairs, it's just what I do.
