New (to me!) '77 CB400F - US model

[Nurse Julie]

Out of interest Matt, what is the winter weather like where you live?

[mattsz]

Out of interest Matt, what is the winter weather like where you live?

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I dare you to click on them...

[Nurse Julie]

Blimey, I was expecting you to say wall to wall sunshine and a constant 26°c 🤣🤣🤣

[mattsz]

Blimey, I was expecting you to say wall to wall sunshine and a constant 26°c 🤣🤣🤣

Yes - 26º Fahrenheit!

[Nurse Julie]

Blimey, I was expecting you to say wall to wall sunshine and a constant 26°c 🤣🤣🤣

Yes - 26º Fahrenheit!

😰😰😰😰😰

[Bryanj]

Buy wd 40 by the 5ltr can withe the pump type sprayer and cover everything with it!

[petermigreen]

ACF50 made for that job

[mattsz]

I have plenty of ACF50 - the first time I used it, it sprayed on like a gel and what a pain to clean it off again in the spring!  I wipe the stuff on now.  Maybe if I warm the spray bottle first...

[Bryanj]

Thats why i use WD, it comes off with engine degreaser

[Laverda Dave]

I've given up with using all the potions to try and stop corrosion during the winter. I now use a dehumidifier 24/7 when the temp gets really cold and dew starts appearing on the bikes in the garage. The dehumidifier I use is a Ruby Dry. I've checked it's consumption on the smart meter and it's 4p/hr on its lowest setting which is plenty good enough for my pre-cast concrete panel but now fully insulated double garage. First time I used the dehumidifier was last year and the bikes suffered no corrosion at all. Added bonus was the garage was a constant 7c but felt warmer as the air was dry even when outside was 2c and damp so it was warm enough to work in (with some extra layers!).

[mattsz]

I've given up with using all the potions to try and stop corrosion during the winter. I now use a dehumidifier 24/7 when the temp gets really cold and dew starts appearing on the bikes in the garage. The dehumidifier I use is a Ruby Dry. I've checked it's consumption on the smart meter and it's 4p/hr on its lowest setting which is plenty good enough for my pre-cast concrete panel but now fully insulated double garage. First time I used the dehumidifier was last year and the bikes suffered no corrosion at all. Added bonus was the garage was a constant 7c but felt warmer as the air was dry even when outside was 2c and damp so it was warm enough to work in (with some extra layers!).

Sounds ideal!  But my garage isn't insulated, and my wife's car comes in and out all winter long.  But, my neighbor will be storing this bike for the winter: at one point he said "basement," and at another he said "garage," so I'm not sure if it will be in a heated space or not - although I'm guessing not.  I think I'm just going to leave it dusty for this winter, I don't see how it could hurt - maybe wipe the chrome and already surface-rusted frame bits with some ACF-50 for grins and call it good.  I'll have the gas tank and carbs in my heated basement for the winter...

[K2-K6]

The oil question for storage.  I've wondered about this, as you do,  thinking that it's better to store it with new oil pumped round it but not run at all.

The issue for used oil is that if it contains much in the way of combustion byproducts,  then the one that really concerns us is sulphuric acid. This should be reduced with later fuels that have reduced sulphur content,  but acid is still there in a form that's not much good for the components,  the new oil is chemically buffered as I understand it to try and keep it near to Ph neutral.  New oil left in for winter wouldn't have to be changed when getting it out of storage,  you'd still only have to do it once.

But, I was looking at a 750 recently that had at some point been stored for longer period. One of the concerns was a clear corrosion affect on the crank bearing shells,  you could see almost that spidery creep you get from corrosion and feel it like a very fine sandpaper with your finger nail. I can't see what else would cause this so tentatively attached it to oil condition when put into storage.

It is of course this acid in the exhaust gasses that has initiated the damage to the exhausts over the years. Any extended running on choke just exaggerates it which is another good reason why you'd not want to run it at all when layed up as you can't get the exhaust hot enough to dry out.

[mattsz]

I started work on pulling the carbs today - following this basic advice:

I had my carbs off recently. Getting them off is simple but putting them back on can be a pain, or rather getting the air box rubbers back onto the carbs can be a pain - if they have age hardened.

Undo fuel hose from tap and remove petrol tank

Undo / remove throttle cables from carbs

Loosen off clamps on the rubbers between carbs and head / carbs and air box

Pull air box back off carbs and remove air box rubbers then pull carbs back from the head rubbers

You should have enough room to get the carbs out to the side now. I leave all petrol lines and overflows connected to the carbs.

I ended up buying new air box rubbers From DS to make refitting easier after using a heat gun previously to soften up the hardened rubbers.

There doesn't seem to be enough room to do all this - is it just because the rubbers have hardened up and are not flexible?  I've loosened or removed the clamps from both sides of the carbs and the big air filter-to-airbox clamp- everything wiggles around now, but I can't release anything without running out of movement.  Should the rubbers between the airbox and carbs actually be removable from both of those items?  They seem really stuck, I'm afraid I'll crack the airbox if I force anything.

Any further advice, or just persevere?

[mattsz]

I've read through the Clymer manual, cover to cover - leaves a lot to be desired!  Lots left out, plenty of mistakes (mis-labeled diagrams, removal process descriptions that mention unidentified parts with names that aren't found anywhere else, etc).  I was thinking of trying the Haynes book, but Haynes publishes the Clymer book, too, so maybe there's nothing to be gained?

[AshimotoK0]

I've read through the Clymer manual, cover to cover - leaves a lot to be desired!  Lots left out, plenty of mistakes (mis-labeled diagrams, removal process descriptions that mention unidentified parts with names that aren't found anywhere else, etc).  I was thinking of trying the Haynes book, but Haynes publishes the Clymer book, too, so maybe there's nothing to be gained?

J
CB400F PARTS

https://www.dropbox.com/s/u51uf0p1dv6m29q/Honda%20CB400%20F%20Parts%20Manual.pdf?dl=0

CB400F PARTS USA Searchable

https://www.dropbox.com/s/j0hysqub5jsfg46/400-4%20Part%20List%201975%20searcheable.pdf?dl=0


CB350/400F SHOP MANUALWORKSHOP

https://www.dropbox.com/s/1n3w5433jkph228/350F%20400F%20_4%20Shop%20Manual.pdf?dl=0

CB350F Part Manual

https://www.dropbox.com/s/7pieydvznvy7nhp/CB350_F_F1%20Full.pdf?dl=0

CB400F DEALER SETUP INSTRUCTIONS .. RARE !!

https://www.dropbox.com/s/ewl1d9td0nhxeya/CB400_set-up_man.pdf?dl=0