OAP Ted's CB400F2 rebuild - engine not run for about 12 years.

[K2-K6]

Yes certainly,  but with acknowledging where the castings support themselves in vertical load rather than the end of the fins, which will guarantee breaks.

Hopefully you'll not need them if they come apart.  The head gasket (in description of sticking in other thread) will hold quite well if assembly is correctly done and surfaces degreased as Honda usually placed strategically important "tacky" areas near to oil transmission routes in getting non leaking assembly.  It's not massively strong,  but is designed to have a sealing integrity as you describe.

[McCabe-Thiele (Ted)]

Teds 400  block by Macabe Thiele, on Flickr

400-4 cylinder head by Macabe Thiele, on Flickr
old head gasket by Macabe Thiele, on Flickr


Thanks smoothoperator for the tip - I used a plastic wedge as used by double glazing fitters and gently tapped it int on outer corner. Fed plenty of WD40 into the gap - in a series of tapping the wedge with a rubber mallett and removing it then tapping the head all round it finally let go!

The cylinder head has been off before as there are small witness marks from a chisel or screw driver on both sides. So far looking good - the head gasket is a black material - no sign of blowing anywhere.

I suspect that the exhuast manifold head connections have been leaking with the blow by building up a carbon deposit causing an external bond between head & cylinders.

The engine has clearly been running rich either beforehand or since I had it running.

[McCabe-Thiele (Ted)]

piston close up by Macabe Thiele, on Flickr

All of the pistons look like this they have Honda brand on the skirts, some carbon between the first & second ring just a light brown coloration above the oil control ring. Bore remarkably wear / step free.

Any observations / comments welcome.

[Nurse Julie]

They look stunningly beautiful compared to the ones that came out of my engine Ted 😬😬😬

[McCabe-Thiele (Ted)]

I remember your tear down pics they were scary!

[K2-K6]

The whole thing doesn't look bad at all really.  Looks like it's been well oiled from the components on view, even the cam looks as though it's been run with correct clearance for valves from that cursory picture of it.

Head gasket all seems to have been running with no leaks, indicating competent last intervention from whom so ever.

As you already recognize,  it's been running "generously" jetted with that colour and carbon.  For some time too, as you can see the "correct" colour of exhaust valves as undercoat  !! with a fair thickness of carbon on top of that.

If the rest of the components follow suit,  then it seems like you've a decent one.

[Laverda Dave]

With luck those Honda marked pistons may be an indication it's still on standard bore size.

[McCabe-Thiele (Ted)]

frame ready for full strip down by Macabe Thiele, on Flickr


engine out on a NJ engine mount by Macabe Thiele, on Flickr

My brother helped me lift out the engine today its standing on one of NJ's engine stands with an Aldi centre Isle wheeled board loaned from brother.
It came out easily - landed on some Kingspan then upended to attach to engine stand - simples!

[McCabe-Thiele (Ted)]

My next phase is to strip down the frame I'm thinking rear end first as it's sat on the centre stand followed by front end with some blocks of wood as required.

[McCabe-Thiele (Ted)]

rear swing arm by Macabe Thiele, on Flickr


Back wheel removed without any issues likewise rear shock absorbers & rear swing arm all made relatively effortless by using my impact driver on the large nuts.

[McCabe-Thiele (Ted)]

More frame stripping, handlebars removed, frame supported on wooden blocks to fascilitate front wheel removal. Noticed the steering was like a three-penny bit when wheel removed.
 
Both telescopic fork legs removed together with top & bottom yokes plus searching for lost ball bearing that went everywhere - so far I think I have recovered 34 in total!
My Haynes manual reads 37 off - odd total. They will need replacing anyway due to general rusting, likewise the bearing cups etc.

Update I have now found 36 of the ball bearings !

[McCabe-Thiele (Ted)]

This morning having examined the steering outer bearing races have decided they need replacing due to rust etc -  upper & lower bearing surfaces drifted out with ease.

No key for the steering lock so old one drilled out (followed guide on a previous post here to choose the hole position) - kept the spring as not sure my new lock has one or not.

Hardest job today was removing the brake stopper/stay pivot bolt from the rear swing arm. The inside nut was well rounded so had to cut the nut off with junior hack saw. If they are readily available I will get a new one as it's a sholdered bolt with a narrow top head.

Only item left on the frame now is a wire hook thing near the steering clumn on the rhs- I guess its a wiring /cable run retaining hook of some sort .
Rear swing arm bearings nice and free - move out by hand pressure  so they will be pushed out to check for wear. I suspect they have been replaced at some time as they are too clean & well greased.

Next is thinking time to decide if I'm sending the frame for powder coating or if I'm going to flat it down & rattle can paint it. I have decided I do not want black - thinking of a midnight blue instead.

I'm back inside as it's pretty cold in my garage today - just made a Kidney Madras sealed meat first then sauce out of a jar - its' in the oven for tonight as Wendy has been called into work again for Covid Vaccine administration work.

[McCabe-Thiele (Ted)]

It was bitter cold in my garage today so all I managed to do was remove a broken off grease nipple on the rear forks.

As I started to drill it out it rotated freely screwing all the way down instead, I reversed the drill action - it almost came right out.
Last few turns done with the aid of a hammered in allen key and out it came.

Not very exciting I know but in the grand scheme of things just wanted to share my good luck.

[Nurse Julie]

You're making great progress Ted.

[Laverda Dave]

Good work Ted, no use rushing. I've brought bits up into the house to clean them up, much to cold in the garage.
As for your frame, I have just sent the z400 frame to a company in Windsor called Microblast (they advertise in Classic Burke, sorry Bike 🙂). They have quoted me £300+vat to blast and powder coat the frame, swing arm, main and side stand, yokes, headlight bowl and 31 yes, 31, brackets (Kawasaki knew how to make a bike heavy!). Turnaround time is 10days. I'll let you know about the quality when I get it all back. The price includes some parts that are satin finish.