750 K2 Strip & Rebuild - help please

[Sesman]

One for Mr Honda. Can’t imagine why they would be needed though.

[K2-K6]

Putting new brake pads in today, and asking why there are no spring washers stipulated for the main caliper bolts (#22)? If there’s a couple of bolts I don’t wanna come undone these two would be toward the top of the list…

It's a tensile load path (pulling the bolts principally into stretch) that is holding onto the hydraulic action of braking application. They have enough torque on the bolt when assembled that they aren't going to come undone in use.

The bolt is effectively stretched to a force greater than any spring washer could assist in this application.

[Sesman]

And they are not subject to vibration, at least of a harmonic amplitude that would justify further treatment. Now if it were an engine mounting bolt that might be a different matter.

[Lobo]

Thought pls on what’s happening here with the instruments- it’s doing my head in. AFAIK all components original, including new OEM clock rubber surrounds. With the rubber locators seated within each instrument slot and upper bridge slot, the Rev counter sits a few degrees to the left, and the speedo even more degrees out to the right. If I twist them to straight ahead obviously those rubber locators cease to locate / do their jobs.
What am I missing? (Tbh this problem had always been there - I just shaved the previous rubbers…)

[Oddjob]

Mounting bracket bent? Possible old crash damage never fixed.

[Lobo]

Hi Ken,

The instruments sit squarely in the mounts. The issue is that their angular ‘anchors’ (ie the locating strips on the rubber mounting bands) skew the two gauges. (Think of a time clock mounted with #1 uppermost, or a dartboard with #20 off to the side!)

I now see that there was a rubber band part # change within the K2 run, as well as  both instruments. And as luck would have it… I have the earlier bands. I’m guessing the issue is here - aargh.

[Lobo]

….what’s the point of the (CB750K) muffler connecting tube pls folks? (#12)

[Oddjob]

Same as the 500, for pressure equalisation I believe.

[K2-K6]

Cross talk for exhaust pressure from those cylinders connected to help scavenge from active pot and improve efficiency.

Long pipes are always working at lowest rpm to improve torque and response low down in the range.

[Lobo]

Thanks gents.. I kind of figured all to do with equalising pressures etc, but given they’re so far down the system and practically next to the atmospheric opening I was having trouble believing they did much. Would a larger diameter pipe / and or a cross-connector near the head not perform better wrt scavenging active pressure?

[Lobo]

7 months ago I figured new tank / panels (thanks Menno!) and a quick paint of the engine was what my K2 needed. What turned out was a complete full-on restoration; I’ve been down and dirty with all 2500 components. Absolutely nothing has  escaped attention or refurbishment.

Today I finally took the bike out for a run, in these first 30kms no fewer than 3 folk approached to have a chat / take photos. The bike is frankly stunning…
No leaks of any fluids, starts on the button, idles at a smooth 1000 RPM and, certainly <4000 RPM, has no carb quirks. Bloody chuffed, and so a MASSIVE thanks to all those who helped with advices etc along the way.

From my perspective, the cost has been frightening, and it’s money I’ll never see back. Tbh I don’t know the final figure as Mrs Lobo does all the banking here … she was constantly telling me off. (In one ear & out the other 😂)

The other memorable bit was the fasteners - what a complete and utter pain I found it zinc and nickel-cobalt plating all that stuff. Draws full of all OEM nuts and bolts would have made this restoration far more pleasurable - or even a good plater… this was another lesson wrt how hard it is to find certain trades.

Anyhoo, done for the next 10-20 yrs, I keep looking at the thing and wishing it could stay this way.

Thanks again to those contributors,

Simon.

[Nurse Julie]

Lovely job there Simon, she looks lovely 😍😍😍

[McCabe-Thiele (Ted)]

Certainly look a stunner - as regard the cost of restoration that's anecdotal.

We do it not as a business but as a rewarding hobby - you rightfully  should be very proud of the end product.

[royhall]

Fantastic job Simon. I know how hard that is and I'm not that anal about fasteners etc. You must be well into 5 figures there, they are so expensive to do now it's really not worth it, unless like you, you already own the bike. These days it's cheaper to buy one done, as I am finding out at the moment. Anyway, well done mate.

Sent from my Pixel 6 using Tapatalk

[Laverdaroo]

Thats an absolute stunner, well done that man!

Dont worry about the money Simon, you could have bought something for the house! Thats a far better use of your dosh