Topic: How To Retorque Heads

[Venturous]

I have the engine pulled from my K1 CB750 to clean and polish as part of the restoration.
I don't see much need to tear it down as it was running well as near as I could tell.
There was however a wet area of gunky oily mess near the outer right pipe. I am
thinking maybe just retorquing the head bolts might help that and now would the time
to do it.

I searched here and read where someone posted instructions paraphrased:

"Simply loosen then retorque the head bolts in the proper sequence"

Now, I could read this two ways and wonder which way is how it should be done:

Loosen ALL the head bolts in order, then go back and retorque them all in order

OR

Loosen and then retorque the bolts one at a time in order.

OR

Maybe it wouldn't matter

Which would be the correct way to retorque the head bolts. Thanks.

[City Boy]

Hi.Others may differ,but I would suggest doing them one at a time.  Rock On

[Soos]

Interesting question!


I am going to re-torque my head,  as I recently swapped in a ported head on my bike.
I was thinking of re-torquing before the next riding season really starts.
One at a time seems odd, but I dunno what is "industry standard" for motorcycle re-torquing.


l8r

[WFO]

http://forums.sohc4.net/index.php?topic=41730.msg430782#msg430782

I re-used as suggested, torqued to 22lbs using Two Tired's torque pattern and Honda gaskets:

5lbs in sequence
10
15
20
22

let it sit overnight then loosen in opposite sequence:

20 (may already be loose)
15
10
5

Then tighten again:

5
10
15
20
22

No oil whatsoever.  Perfect.

[Jerry Rxman Griffin aka MuthaF'er]

I believe what you are referring to as loosening then retorqueing is intended to apply to a newly built engine that has not been run and is still out of the frame. I think the guys that have done this let the new engine sit a while then perform this. It's always best to retorque in the proper order.

While I believe it is a good idea to retorque a used engine when the opportunity arises it may not solve a present oil leak so be prepared to be dissapointed. Solving oil leaks around the head in a used engine may require some cash infusion and an engine teardown. It is often the result of the sealing rubbers (as they are officially known) aka rubber pucks, etc that are located between the head and the cam shaft holders becoming hard and brittle thus leaking. However it can be a number of things. It's my opinion that once you seriously loosen the nuts on all the cylinder studs you have possibly just disrupted the sealing of the whole top end all the way to the base gasket. I personally would not loosen the cylinder stud nuts unless I intended to do a complete top end job. Tighten them down, do a top end job, or leave them alone.       

[WFO]

I believe what you are referring to as loosening then retorqueing is intended to apply to a newly built engine that has not been run and is still out of the frame. I think the guys that have done this let the new engine sit a while then perform this. It's always best to retorque in the proper order.

While I believe it is a good idea to retorque a used engine when the opportunity arises it may not solve a present oil leak so be prepared to be dissapointed. Solving oil leaks around the head in a used engine may require some cash infusion and an engine teardown. It is often the result of the sealing rubbers (as they are officially known) aka rubber pucks, etc that are located between the head and the cam shaft holders becoming hard and brittle thus leaking. However it can be a number of things. It's my opinion that once you seriously loosen the nuts on all the cylinder studs you have possibly just disrupted the sealing of the whole top end all the way to the base gasket. I personally would not loosen the cylinder stud nuts unless I intended to do a complete top end job. Tighten them down, do a top end job, or leave them alone.       

Yep i have a leaky top end and have nothing to lose so i retorque all the head bolts ( never loosened them) and the leaks got worse so iam replacing all the top end gaskets this winter.

[Sporkfly]

My personal opinion/experience is that a head should be re-torqued after it has been run to temperature a few times. The vibration and heat could cause the nuts to back off a bit. Follow the sequence and just do a recheck.

This is, again, for a rebuilt engine...

[WFO]

Only problem i have is winter will not officially show up here in colorado lol.

[mrbreeze]

I would pull the top end while the engine is out of the frame and be done with it.If its seeping now....you won't fix that by simply retorqueing the head bolts.Its like Jerry says.....the cam tower seals are hardened with age.
Now if you're the kinda guy that doesn't mind pulling the motor a second time.....I wouldn't loosen them all at once.Also.....now is the time to get that valve cover polished to a chrome-like finish.

[Jerry Rxman Griffin aka MuthaF'er]

I agree with Sporkfly HOWEVER unless you have one of Gordon (Ilbikes)'s "Frame Repair Kits" installed in your frame you have to remove the engine in a 750 to retorque. How many folks are willing to completely reassemble their engine and put it back in their bike, run it, then remove the engine and retorque and the start the assembly all over?? Not me thats for sure. Mine's been out twice with pretty decent results without a retorque but leaks eventually. The next time it's going back together with MUCH MORE HP and a set of heavy duty cylinder studs and bottom end studs AND Gordon's frame kit. It will get the initial torque, the 1st retorque after it sits, then the 2nd retorque after it runs and I won't have to remove the engine to do so, just the section of the frame above the head.    

[Sporkfly]

That's a good point for the 750 Jerry. I don't have experience with the 750, but I am aware that re-torque would be an engine out operation... Since I have a 550, I have a bit less to worry about on that front as I can do all the top end work with the engine in the frame.

I think Gordon's frame kit would be a VERY worthwhile purchase for 750 owners as I couldn't imagine having to pull my engine to do somewhat basic tasks. (Gordon, look, free advertisement from somebody that doesn't even have a 750!  )

[Jerry Rxman Griffin aka MuthaF'er]

Only problem i have is winter will not officially show up here in colorado lol.

WFO,

I'd bet most people don't understand what you mean. Those of us along the Front Range (like most of our Colorado guys on the board) which is the area just east of the mountains, is actually a high desert like area that gets mucho sunshine and clear skies most of the winter with occasional 2 foot dumps of snow. What this means is we can ride most of the time year round. Just not as often during winter.

If you'd like to check out Gordon's kit just ride down on one of the beautiful sunny days with dry roads when there are 4 foot drifts on the side of the road.  

[WFO]

Only problem i have is winter will not officially show up here in colorado lol.

WFO,

I'd bet most people don't understand what you mean. Those of us along the Front Range (like most of our Colorado guys on the board) which is the area just east of the mountains, is actually a high desert like area that gets mucho sunshine and clear skies most of the winter with occasional 2 foot dumps of snow. What this means is we can ride most of the time year round. Just not as often during winter.

If you'd like to check out Gordon's kit just ride down on one of the beautiful sunny days with dry roads when there are 4 foot drifts on the side of the road.  

I will do some more long range riding next summer when i get these gaskets fixed.

[ofreen]

I've told this story a couple of times on this forum, so sorry for the repetition.  Back in '96, my '75 750F began leaking around the head gasket and base gasket enough that it was making a mess and I hate oil leaks.  The bike had 52,000 miles on it at the time.  I pulled the engine and re-torqued the head.  The leaks stopped completely.  In 2002, at 82,000 miles, the seals under the cam holders began leaking badly enough that my jeans would get spattered after a short ride.  When I replaced the seals, I took the opportunity to re-torque the head again, though neither the head or base gaskets were leaking.  The bike will turn over 115,000 in a week or two, depending on how the weather holds up.  Still no leaks.  This is an all original engine that has only been disassembled enough to replace those seals under the cam holders.

My method for re-torquing a head is to loosen a nut or bolt, as the case may be, about a quarter turn, then torque to the full value.  I do it individually.  I use this method on car and bike engines and have always had good results.  I am leery of loosening them all up then doing the re-torque.  I'd prefer that nothing moves.

As was mentioned, while you are in there, definitely replace the seals under the cam holders.