Topic: Checking Torque

[The Gurg]

Basic question, first rebuild, so still learning. Cb750k5

Just closed up the crankcase yesterday. Torqued everything to spec, and followed the pattern for the 8mm bolts.

I used a T bar to fully thread the fasteners, but I didn’t apply any pressure or tighten at all when using the T bar. Then I used the torque wrench. I’m absolutely sure everything was torqued, but worked quick while the 3bond was setting and wouldn’t mind double checking. But I also wouldn’t loose sleep if I just left it. What’s the correct way to double check without compromising the threebond or bolts, or do I just need to trust myself? I’m only concerned with the 6mm bolts.

1.) softly tighten with a T bar and 10mm socket, if it doesn’t tighten more it’s good.
2.) re-torque the bolts
3.) back off a 1/2 turn then torque bolts
4.) leave it alone

[MauiK3]

I would not back them off.
Carefully, with a torque wrench, test them to be at the target torque.

[The Gurg]

Ok here’s an added dimension that I just realized, one of the bolts stretched yesterday. After going through receipts and emails this morning, I found It was from Z1 labeled as a starter cover bolt. The part number is 95700-06056. I must have assumed with the part number it was the correct class, that’s obviously not right. I removed the stretched bolt and replaced with the original as I was combining the cases, yesterday. There are two 56 length bolts above the countershaft bearing, so one of the bolts is still a starter cover bolt with the wrong class and still needs to be replaced.

Any issues with me replacing a bolt without going back into the case or do I need to redo the 3bond? Anyone know where to find that bolt? It’s hard to find.

[dave500]

swapping a bolt out is no worries.

[The Gurg]

Ok perfect, now where do I get this impossible to find bolt lol! 95700-06056

[pjlogue]

For proper use of a torque wrench I was taught by an aircraft mechanic to creep up on the "click" release the pressure, but not unscrew the bolt/nut and then creep up on the "click" again.  This assumes you have cleaned the threads of both the bolt/screw and the nut/hole and oiled the threads (if called for).

Any gaskets you are torquing down on I go back a day after and torque them again without backing off the nut before I torque it.  A lot of gaskets will compress and you will find the nut/bolt isn't tight the day after.

-P.

[HondaMan]

Ok perfect, now where do I get this impossible to find bolt lol! 95700-06056

Honda actually used 55mm there in many of the bikes. If you get a 60mm long (Ace Hardware) flanged bolt and it bottoms out, just grind off 1/8" (3.5mm) or so. Or,  just run a 6mm bottoming tap into the hole to finish the threads all the way down, as the hole is over 60mm deep over the starter housing.

The 56mm version of the bolt was used to allow differing vendors of the starter motor: some are less tall (thick) at the bolster end than others. Mitsumi made some of the starters: I don't know who the other vendor is, though. Those 'other' motors are not marked inside with the manufacturer's name. This same approach is used for other engine parts like the cam covers from teh New Factory when installed onto Old Factory heads: the screws became 63mm long instead of the usual JIS 5mm step-lengths, so the shorter 60mm can possibly strip, while the 65mm may bottom out. I go longer and deepen the threads with a tap, occasionally maybe adding a 6mm washer at the top if the problem persists, just to use up the length.

When Honda was making these bikes in the 1970s, it was one of the biggest industries in Japan. Their vendors were only too happy to come up with oddball screws/nuts/bolts to get a Honda parts order.

[The Gurg]

The bolts aren’t for the starter it’s these two above the countershaft bearing.

[The Gurg]

I got the part number from the parts diagram on the partzilla site. Wondering if the number is wrong?

[The Gurg]

Just checking back on the solution for the missing bolts. Any issues with following Hondamans advice even thought these are case bolts rather than starter motor cover bolts? Another idea is to use a stud nut and washer. Any issues with that? Or maybe someone knows where I can find these? Looks like another part number is 92000-06056-0A

[PeWe]

I have ordered the hex M6 screws from Yamiya with correct logo on the heads. You order on their screws/bolts and nut page by diam and lenght, no part no.

CMSNL parts lists show the lenghts.
Important to double check the lenght before tighten it.
I've made a mistake using a little bit too long one just in front of the sprocket. The bottom popped before 5Nm.
I was lucky to later find it in oil pan without any major marks from trans contact.
I was not aware of popping bottom while it happened, I thought I entered a not used area of the threads with eventual popped bottom in mind.

Most of these are fine with 10mm thread lenght.

Side covers have also threads in cases where bottom can pop if too long screw is used.
Measure hole with a caliper or a pin/drill if not sure.

[The Gurg]

Awesome. So this (link below) flanged bolt should be strong enough for the case?

https://www.yamiya750.com/index.php?main_page=product_info&cPath=158_162_285_286&products_id=3418

[PeWe]

Yes, correct.
You need more. Early engines had not flanged heads according to CMSNL, hex with washer. K1- got flanges.
I made a list yesterday so I can verify my stock of bolts and needs to order. I looked at CMSNL charts.

Lower case M6:
6×40 4pcs
6×50 3pcs
6×100 3 pcs
Upper case:
6×40 2 pcs
6x56 4 pcs
6x80 2 pcs
6x100 4 pcs

Plus the rear M8, M10 bolts, washer and nut.

K6 got M8 flange bolt beside front sprocket, earlier M6.