Topic: Icy Bikes - '76 CB400f resto - getting ready to change out the transmission

[zachz]

Yeah, also needed to do the sheared tensioner and wanted to take a look inside.


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[zachz]

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[SOHC4 Cafe Racer Fan]

Shelving it?

[zachz]

Interim workbench.


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[zachz]

Working to get everything cleaned up before I take the remaining bits off.  What is the appropriate paint for the exterior engine bits again?  (I can go search, but I am lazy...)

[zachz]

So I've got the engine apart and am waiting on a few seals to arrive.  The transmission gearsets appear to be in fine shape, and I've had some fun seeing how the shifting mechanism actually works.  The reason I cracked the cases in the first place was to figure out why I was seeing gear-slip only in 5th gear on anything over light acceleration - and I have to think that I need to adjust the gear shift drum slightly to solve my problem, though reading through the 350/400 manual, it's not exactly clear what or how I might go about that.  I can stare at it and probably figure it out, but anyone have tips?

[SKTP]

I had an issue with my 5th. I had one of the two big gears that come off easily flipped. This resulted in my 5th slipping out and making a horrible sound...but I could hold the shifter up with my foot and it would stay in 5th. Obviously this was not cool and I fixed this issue.

edit...just noticed you have a 400f not a 750...my comment might not be  relevant

[zachz]

Might be relevant and would explain why most everything else looks okay - will have to compare the existing gearshafts with the replacement transmission that I procured to see if anything is reversed.

[zachz]

Long-since any updates here - stalled out when I went to clean up the sheared tensioner bolt.  As has been discussed in many other threads, I snapped off the easy-out as I was attempting to remove the sheared bolt and pretty much all forward progress stopped there.  Very slow progress left the engine disassembled over the past two years, but eventually a set of new, hardened cobalt bits managed to work thru the extractor bit and drill out the remainder of the sheared bolt.  I managed to free up the cam chain tensioner pushrod last evening and now finally, FINALLY!, will be able to rethread the sheared bolt-hole and get the engine reassembled.

The machine shops I'd taken it to were reluctant to get involved (hm...).  Looking forward to reassembly.  Will also be looking at the transmission to see if I can't solve the 5th gear slip issue that started all of this work a few years back...

[Don R]

 I like the small turn signals, repro brackets for a 750 K0 will fit the rear and take the small ones too.

 How did the neck bearing swap go? Anything I should watch for?

[zachz]

Neck bearing swap was fin - a bit of pounding to remove the old and then careful tapping and compressive threading to seat the new bearings.

[zachz]

After four years delay, one house move and a pandemic, the engine Is reassembled and operational again!

[jakec]

I just read page one and was in deisbelief that you found a tank so nice, used. Then I saw the date as 2012. You just can’t find them nice like that on eBay these days it seems.