Topic: Retorquing head bolts - any point?

[Patrick]

The engine from my K5 750 is coming out later this week because the oil pucks have gotten so bad that you can't ride it without an oil-proof rain coat. Not that I mind, because I let my college boy son take the bike so he would have transportation at school and his idea of maintenance is scraping the crud off the Vetter every once in a while so he can see. I am tired of buying him clothes.

As long as I have the engine out I figured I could go ahead and retorque the head bolts, but I'm wondering if there is any point to it. The bike has about 30,000 miles on it since I rebuilt it four years ago and, other that the camouflaging James Bond sort of oil fog it lets off behind it, it runs just fine, which is a testament to Japanese engineering.

Have I got anything to gain or lose with a retorquing?

Thanks, y'all.

Patrick

[MCRider]

The engine from my K5 750 is coming out later this week because the oil pucks have gotten so bad that you can't ride it without an oil-proof rain coat. Not that I mind, because I let my college boy son take the bike so he would have transportation at school and his idea of maintenance is scraping the crud off the Vetter every once in a while so he can see. I am tired of buying him clothes.

As long as I have the engine out I figured I could go ahead and retorque the head bolts, but I'm wondering if there is any point to it. The bike has about 30,000 miles on it since I rebuilt it four years ago and, other that the camouflaging James Bond sort of oil fog it lets off behind it, it runs just fine, which is a testament to Japanese engineering.

Have I got anything to gain or lose with a retorquing?

Thanks, y'all.

Patrick

Is the head gasket leaking? If not there will be those who say leave well enough alone. If it is, I'd goose the head nuts another lb or two. That's assuming you don't want to fix the head cheese.

Even if it weren't I'd goose them anyway, being careful to follow the sequence in the manual. And don't forget to follow up tightening those smaller bolts as well. after the head nuts.

That's just me, YMMV

[simon#42]

well i would , re torqued mine after 1000 miles and was surprised  how loose all the bolts actually where

[bucky katt]

within 500 miles of rebuilding the head should be re-torqued, because of the way things get after heat cycling a few times. thats why i love the frame kit i got from Ilbikes so much. it makes re-torquing the head bolts a 2 hour job instead of 2 days.

[Toxic]

He has 30,000mi on the head, I wouldn't touch it. If you are rebuilding the top end then ya I'd retorque after 500 then 1000 miles.

[Bill K]

 Don't mean to thread jack, but. When I do my rebuild this winter does the engine need to come back out to re-torque the new HD head bolts? I don't have the frame kit.  Thanks

[Gordon]

Don't mean to thread jack, but. When I do my rebuild this winter does the engine need to come back out to re-torque the new HD head bolts? I don't have the frame kit.  Thanks

If you want to re-torque, then yes, the engine has to come out. 

[Patrick]

Ideally you would retorque after 500 or 1,000 miles, like other posters have noted. That is kind of a pain in the butt with the 750, so usually it doesn't get done. On some of my bikes the manufacturer suggests you check the torque on the head bolts as part of the regular maintenance. On those bikes, though, the head bolts are readily accessible.

My question stemmed from the number of miles on the bike since the rebuild. Since the head nuts had never been retorqued, I don't know if it serves any purpose to do it now, or if doing it now could actually be counterproductive.

Patrick

[Gordon]

My question stemmed from the number of miles on the bike since the rebuild. Since the head nuts had never been retorqued, I don't know if it serves any purpose to do it now, or if doing it now could actually be counterproductive.

Patrick

I'm in the "if it ain't broke, don't fix it" camp on this one. 

[MCRider]

Don't mean to thread jack, but. When I do my rebuild this winter does the engine need to come back out to re-torque the new HD head bolts? I don't have the frame kit.  Thanks

There is nothing in any rebuild manual I've ever read saying that retorquing was necessary on a CB750, stock studs or otherwise. Nor have I ever done it.

Five years in Honda dealerships and I never saw a mechanic retorque one that had been rebuilt. Nor did one ever come back needing it.

Since they had a head gasket leak problem early on, so on a leaker sinching them up a tad was often helpful, if they were out of warranty.

With the HD studs, tighten them in proper sequence, and once you get near your target take them incrementally a few lbs at a time. You should never have to go back and retorque them.

[Gordon]

There is nothing in any rebuild manual I've ever read saying that retorquing was necessary on a CB750, stock studs or otherwise. Nor have I ever done it.

Same here.  I've never re-torqued the heads on any of the sohc4's I've rebuilt, and have never had one leak after rebuilding.  Yet.