Honda CB400NA Superdream - new money puddle.

[davidcumbria]

Good luck with the resto Ted looks like a good buy and that model would also high on my list as an interesting rideable bike in the end. Getting started on my BMWR80 soon after I’ve sorted a near engine death belt issue on my Volvo Xc60. Hope the thumb gets better !

[McCabe-Thiele (Ted)]

It's weird the bloke I bought my CB400NA from has sent me a photo of his latest bike, another CB400NA, at a glance it looks in quite similar condition overall.

Might be he is buying & selling or that the one I have was just too much work with the comments by a previous bike repairer about the engine being delicate.
Having read all the history of the bike a few times it had new genuine Honda block & standard pistons fitted in Oct 2015 at 48,859 miles it has now covered a recorded 50,678 miles with documentation that supports the recorded mileage and lack of use.

Looking at the statements dated August 2019 at 50,646 miles  "this  engine is delicate and would not advise being taken apart again " this might be why the last owner has decided to move it on.

The upper crank case has had some Timeserts fitted with a report of oil leaking from cracks in engine casing as far back as  2014.  Reports do not seem to specify if it was the lower (gearbox) casing or the upper. There is a decent lower engine/gearbox casing in my box of spares.

Looking around on e-bay it appears that stripped head bolt threads are pretty common. Worst case scenario is I either need to find a better upper crank case or the existing one will need more head bolt threads repairing. There is no sign at the moment of any slow oil leaks from the engine when it is not running.

I've seem a few adverts for complete 400N engines, I suspect stripped head threads is pretty common - makes me wonder why Honda  did not stick to studs & nuts.

Pretty sure the engine is going to end up being fully dismantled, I still plan to fire it up again when the cam top cover is back on just to see if there are second or third areas of oil weeps/leaks.

I'm planning/hoping  to have her running again by the end of the week - currently having to cope with a water leak somewhere under the bath area that is causing a small circular damp patch in the rear lounge.
Plumber calling tomorrow to give me an estimate.

.damp patch circle by Macabe Thiele, on Flickr
 

[Johnny4428]

Ted in my opinion any thread repairs if carried out competently will be stronger than original threads as you probably know. So I wouldn’t be put off by previous repairs, cracks is a different story. More annoying would be a water leak in the house!😳

[McCabe-Thiele (Ted)]

Ted in my opinion any thread repairs if carried out competently will be stronger than original threads as you probably know. So I wouldn’t be put off by previous repairs, cracks is a different story. More annoying would be a water leak in the house!😳

The optimist in me did wonder if the so called 'cracks 'were casting marks. If the bottom casing has cracks can I fit the 'spare casing'  I have assuming the bottom cases are interchangable with the upper half as the mains arrangement is an internal coded mains cap arrangement?

As you can imagine the water leak (a small damp patch at the moment) is my priority. I've made a small hole at the centre of the circular patch with a bucket directly below just in case it suddenly accelerates.

Today there has been what appears to be one drip onto some dry loo roll in the bucket. It's how the plumber will find the source of the leak and what needs to be removed to fix it.

[Bryanj]

Yes the lower case can be swapped Ted

[McCabe-Thiele (Ted)]

Yes the lower case can be swapped Ted

I have since looked at the 400N parts book that is quite different from the CB400F & 500 K1 versions.
Two part numbers are listed for the 400N depending on the engine number, I have a spare lower crankcase but not sure if the two part numbers are interchangeable.
The book lists 11200-413-781 & 11200-413-782 so whilst not disputing the swapability wondered if there is some easy way of identify the spare casing I have as a 781 or 782?


Is it connected to the so called kicker models Bryan?

[Bryanj]

Probably Ted, never got that far in. Did change top set on a brand new 250 but thats a different story

[McCabe-Thiele (Ted)]

My thumb wound is sufficiently healed so this morning the cam casing has been cleaned to remove the worst of the oxidation followed by a coat of Simonize silver matt engine paint.

[McCabe-Thiele (Ted)]

I am pleased to report that the cam cover oil leak is fixed with no sign of any other oil leaks.

I'm pleased I removed the coils & CDI unit as it made fitting the cover back really easy. I used Red Rubber grease to hold the seal into the cover, carefully put it in place, checked it was in place all the way around. New top seals & bolts fitted.

I've made a replacement cable for the battery to solenoid lead using some new cable & one new soldered end connection. I reclaimed a 90 deg terminal for the battery end. Not perfect but a good temporary arrangement until I can source something closer to the original battery terminals. Had to use the gas ring on the cooker to get the terminals hot enough for the solder to flow.

[Sesman]

Never mind all that…what’s happening with the leak?

[McCabe-Thiele (Ted)]

Never mind all that…what’s happening with the leak?

History, I have no oil leaks now!

Next going to do an oil & filter change & check the balance shaft chain for tension. I've had advice on how to do it from Bryan & Ken.

[Sesman]

The water leak Ted, the water leak🫣

[McCabe-Thiele (Ted)]

Ah sorry I was in bike mode!
We have a low threshold bath as Wendy can't get her leg over due to hip replacement a few years ago. ( bath not me).
We have a fancy electronic shower with a fixed rain head plus  the usual hand type shower head on an adjustable rail. It's a power shower with a folding side screen so it uses almost as much water as a bath.

Plumber came on Tuesday and declared no leaks from the various pipes at the foot of the bath. He was a bit stumped as to what was causing the obvious wet patch on the lounge ceiling. He tried the bath taps no leak on the drain from the bath. As a last resort he asked me to switch on the shower. Nothing for the first few minutes then water appeared between the end of the bath and the stench pipe cladding in the corner of the bathroom. He did a video with his phone.
The bath is not dead level but tilts slightly away from the taps and the shower section. During a long shower then water runs along the seal between the bath & the wall tiles and was leaking at the far end.

After our house fire the cladding was pulled away from the walls by the fire brigade to ensure there were no small pockets of fire that could restart after they had left. Although the bathroom was not damaged the cladding had to be replaced due to the holes they had made in the uPVC. The builders just sealed in the new cladding but the joint where new met old failed to last.(It's lasted 6 years).
It just needs all the sealant round three sides to be removed and replaced with a good quality sealant with the bath full of water until it's dried.

I've decided to let them do it, sounds too much like removing gasket material from an engine block.🥱🥱🥱

[AshimotoK0]

Charlie finally got round to pricing his Ted plus he has another one now if anyone else on here wants to share your journey 

https://www.oxfordclassicmotorcycles.co.uk/bikedetail.aspx?bike=5518

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https://www.oxfordclassicmotorcycles.co.uk/bikedetail.aspx?bike=5536

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[McCabe-Thiele (Ted)]

It took a while for it to be priced Ash, more in line with the current market, might be I got it wrong, I know it was more than I wanted to spend plus it probably needs little work doing to it.

The bloke I bought my 400 SD from has gone and bought another 400SD one with 16k miles on the clock from somewhere near Chester for £1800 IIRC, I saw it when I was looking for one, it's dropped a few hundred.
Too tidy for me I need something that needs working on.