Question about head bolt torque...

[TeeCat]

Guys...

There is an existing thread on this topic, which I have read with interest, but I didn't want to commandeer it, so I thought I'd reference it instead.

For the first time since I have owned my bike - and just after having gone to winter-weight synthetic, interestingly - I have discovered a slight oil weep right around bolt #5, at the gasket between the cases and the pot, left rear corner as you sit on the bike. It seems slight, but it's also new, I think. But the timing (cold temps ad light weight oil) is interesting.

I have never been into this motor myself, but can't swear that a PO has not. I have never, therefore, torqued or re-torqued the bolts. That said, I'm not sure if I should just keep an eye on it (I ride very little in the winter) and see if it clears up when I go back to 20W-50 (synth, as the bike seems to like synth otherwise), attempt a re-torque of the affected bolt(s), or attempt a full re-torque. I have never done it before, but I suppose I would if needed, and just take my time and do it carefully/correctly. I just don't particularly want to disturb a motor that otherwise seems to be running like Flo-Jo.

Thank you!

TC

 

[littlebill31]

It's simple to do. Just remove the gas tank, take off the top engine mounts, get a good torque wrench and follow the specs/order in that thread. It takes me no time. Just take your time, back the nuts off, clean 'em up, and go in the proper order. I use 5twins specs (post #17) of 30-35 ft/lb torque.
It's totally worth doing all 15 bolts. The #9-11 are a little tricky, but not bad. My '82 was spitting bad around the head gasket. No time at all later...fixed!!!

 

[TeeCat]

Thanks much, Bill. I might have to just go ahead and try to take care of it on a mild weekend day in the near term.

Now, (dumb question alert!) when you back them off, do you remove the nuts all the way, one at a time, and then re-torque to spec? I'd think so, so nothing risked getting moved around.

And are you just cleaning the threads and washer tops? And no anti-seize, right? And those specs are okay for a '73? I know they changed them some.

Thanks again, Bill.

TC

 

[littlebill31]

I took them all the way off and used a wire brush and green scratch pad to clean the crap off the bolt and studs. I used no lube or anti-seize, but some do. I replaced the rubber washers with the brass ones, but you can re-use the old ones as long as they are not all boogered up. I've done it before.
The manual calls for 22-25 ft/lb. I used the 30-35 because they just felt way too loose....and 5twins used it, so I'm not too worried. You might still want to check. I started at 20, then moved up in 5 lb increments 'til I got to 30, where I stopped. I left 5 ft/lbs for "just incase".

 

[TeeCat]

But all of them off at once, so your motor was essentially entirely untorqued? That's what I'm not 100% clear on, tbh.

Since I really have no idea what the PO did or not, but have never had a gasket leak on this bike before, I wonder if I should just spring for new brass washers, or just try to use the existing ones to see if I can take care of the presenting issue? If I get new ones, the job will have to wait, though I don't see this as urgent at this point.

I suppose I'd better go with 30 to start. I have a pretty stout torque wrench (my ft pounds one - I forget the drive size), and I might have to get one of those angle extensions that twins mentioned.

Thank you again!

(Say, those rods don't have any role in holding the case halves together, do they? I was hoping against hope that my long-standing little left-side case seam weep might be fixed by a re-torque... )

TC

 

[blackbetty]

I was torquing down my headbolts this weekend after putting my 700 kit in and I broke one of rocker box to head bolts on account of a SHIT 1/2" torque wrench.

Luckily I was able to get the sheared threads out with my fingers after removing the rocker box!

I bought new grade 8 hardware and did it again with a real 3/8" craftsman torque wrench. I used 10w30 oil on the 8 studs and anti seize on the rest, I feel like I was able to get a much more accurate setting using the lube on the threads.

My advice is to use a good torque wrench!

 

[littlebill31]

I do one bolt at a time.

No, the rods hold the cylinders and head on, not the case together. Those are the bolts on the case bottom, underneath.

 

[TeeCat]

Ah, okay. I think I'm square then. Just have to make up my mind on the washer issue. I suppose if I do get new washers, I can use 15 bronze ones instead of the four OEM crown nut ones, right? Or should I go with 11 bronze and 4 OEM for the outside crown nuts. Not sure if the bronze is "better" or not.

Thanks again, Bill. Will keep you apprised. Ain't you thrilled?

TC

 

[5twins]

You only need 4 brass, bronze, or copper washers to replace the rubber/metal ones under the 4 outside acorn nuts. All the rest can remain stock steel ones (or swap stainless on if you like). Replacing all with the bronze would just be a waste of money. You need the softer bronze washers where the rubber ones are now to seal those stud holes because they flow oil. None of the other ones do, so like I said, just a money waste replacing them.

 

[littlebill31]

Thanks 5twins, I forgot to mention that.

 

[TeeCat]

Okay, thanks, twins! I'll order four bronze ones (Mikes Part #01-0651) tomorrow; I think this job can wait until they get here, it being winter and all. Might spring for some new stainless ones for the inside ones while I'm at it.

TC

 

[5twins]

I replaced all the smaller ones with stainless, keeping the originals for the 4 inner acorns. The thing with these acorn nut washers is they're quite thick, thicker usually than a plain washer. You need that thickness so the acorn nut doesn't bottom out on the stud before it's applying enough pressure to the head. And about this head re-torquing - it's a routine maintenance thing with these bikes. I do mine every spring.

 

[TeeCat]

Got it, twins, thank you. And the regular need for it is good to know. I like to think this will be my first assurance that it will have been done properly.

 

[TeeCat]

Guys, sorry... couple little questions before i order my washers:

- Is there a preference of either the OEM rubber type or the bronze ones for the outer four, since they flow oil? And...

- I noticed that the studs are several different diameters and torque ratings. If I replace the washers for the inner studs and studs other than the outer four, do the inner diameters of the washers matter? And I'm not seeing replacements for those (steel/stainless) at Mikes. Am I overlooking them, perhaps?

Thank you. It's too cold to ride comfortably so maybe this is a good time to do this maintenance.

TC

 

[gggGary]

Don't have much to add but will blather anyways. As mentioned watch washer thickness, general duty stainless washers tend to be stamped out of thin stock. That's an issue for valve cover washers too. Plus # what ever on retorquing being good preventative maintenance. I do them as part of the first round of maintenance on any XS650 I start working on now. Remove, clean, lube, semi tighten, ONE at a time. Every year? well it probably won't hurt but I would think 5 year or 10,000 miles intervals would be reasonable...

 

[littlebill31]

Teecat,
I'll check those washer sizes out in a bit.

 

[littlebill31]

This is what I found. My good caliper is not working, so I used my nice mm rule, but eyed it up. These numbers might be a touch off, but should be true.
Washer size for:
10mm studs, (#1-8), is 22mm OD / 11mm ID
8mm studs, (#9, 10, 12-15), is 17mm OD / 8mm ID
6mm stud, (#11), is 13mm OD / 6mm ID

 

[blackbetty]

I used brass sealing washers on all 8 of my studs, mostly because I wanted all 8 head bolts to be uniform, and also because I like the way it looks

I used grade 8 hardened washers under everything else, I found the stainless ones would squish under torque.

 

[TeeCat]

Guys, thanks for this additional information. And thanks, Bill, for the measurements.

Looking forward to learning how to do this properly!

TC

 

[5twins]

The preference is for the bronze/brass/copper over the O.E.M. rubber ones. Those rubber washers were a screw-up on Yamaha's part. They allow those 4 outer acorn nuts to back off and come loose all the time. They are probably the #1 reason for XS650 head gasket leaks. The bronze/brass/copper washers are soft enough to seal but hard enough to retain your torque.

Now that you own a 650, I'm sure you notice and take a closer look at any 650s you happen to see while you're out and about. What you're going to notice, now that you're aware of it, is that most you see will have leaking head gaskets. Look even closer and you will see those original rubber washers still in place on the 4 outer studs. Changing them out is pretty near at the top of the "Must Do" list when you get one of these.