Topic: Fork drain plug thread 73cb450f

[kyle56403_]

Does anybody know that the threading is on the drain plug for the front forks on a 73 cb350f i recently changed the fork oil and accidentally overtightened and snapped the small drain plug and i want to get a replacement.

[willbird]

Does anybody know that the threading is on the drain plug for the front forks on a 73 cb350f i recently changed the fork oil and accidentally overtightened and snapped the small drain plug and i want to get a replacement.

Is this just a screw with a copper washer ?? If so then on a different model it was standard Metric pitch for that size screw. For the CB750K m5 comes to mind but the mind is not to be completely trusted in my case ;-).

Bill

[Rayzerman]

I you look on the parts diagrams they tell you the size..... M6 x 8mm long.

[newday777]

Does anybody know that the threading is on the drain plug for the front forks on a 73 cb350f i recently changed the fork oil and accidentally overtightened and snapped the small drain plug and i want to get a replacement.

Welcome aboard the forum Kyle
You are asking about #26 drain bolt? 6mm x 8mm

Where are you located?

[Deltarider]

In general: these bolts positioned where they undergo all weather conditions, must be handled with care. Do NOT use a torque wrench on 6mm bolts. Don't ask me how I know.

[MauiK3]

I often use a torque wrench for the smaller fasteners but since most of the time it's in aluminum I set it to a bit lower than some of the specs say. Many seem pretty high for the castings we are often working with.

[willbird]

In general: these bolts positioned where they undergo all weather conditions, must be handled with care. Do NOT use a torque wrench on 6mm bolts. Don't ask me how I know.

One place I used to work due to human power shortage they moved unskilled people into mechanical assembly. They quickly decided that it was simpler to force them to use a torque wrench on EVERYTHING because they had no experience to know how tight a bolt should be. They called me back to a large piece of equipment that had EIGHT grade 2 1/4"-20 bolts twisted off in the roll cage on the machine. The guy looked at the bolt and saw a number stamped on the head and presumed 20 ft lbs was what the "20" or whatever it was LOL. But he did not stop when the first one twisted off, he got all of them :-). Lucky for me the twist drill ran them into the hollow inside of the tube really easy.

[Kelly E]

On small bolts that thread into aluminum I use this WWII vintage Plumb Tools 6" x 1/4" drive extension instead of a torque wrench. It works like a torque stick, the extension shaft will start to twist before the aluminum threads strip, you can feel it twisting. I've never stripped any m5/m6 aluminum threads since I got it.

[Rayzerman]

Anything with a copper or aluminum washer and you can tell when they are tight... basically snug and you can feel the bolt scraping into the copper/aluminum.  Absolutely keep the torque wrench in the tool box for small fasterners...

[Deltarider]

Over the years I had developed a pretty good feel of how far you can go and where to stop (just before it snaps my uncle, a car mechanic humouresly used to say  ). Never had a fastener broken. It's only after I had acquired a torque wrench and used it, I had some bolts snapped.
1. A fork drain bolt.
2. Several studs at the exhaust flange started turning in the head. It worked well the first time, I fastened the nuts, but that was it. If you repeat it a second time, the studs seemed to remember the previous time they had been stressed and decided to take revenge. I had to go the Time Sert route for several of them.
3. The four bolts that hold the clutch springs all snapped (on two occasions!) when I torqued them at the prescribed 1,4 kg.
Since then I've returned to using my skill again and I reserve the torque wrench for when it is really needed.
Conclusion: don't loose your feeling by reaching for that torque wrench all the time. You're are only fooling yourself with 'how well that money was spent'. Do as the pro's and reserve that wrench for where it counts like the head. The rest is nonsense IMO. CB Fours hardly vibrate at all.

[HondaMan]

Those fork drain bolts are 6x16mm, with a soft copper sealing washer on them. Don't loose that washer!