1981 CB400NB Superdream Renovation - Winter 2023-24 Project

Hi blue.  What paint did you use mate? I’m about to do mine and want to buy one that’s been used.  Cheers.  

Nothing to do with SDs but a bit of fun. I made a Rickman Metisse back in 2014 and came across this photo of the bike raised for wiring and oil line plumbing.  The joys of a light machine:

there is nothing in the world sounds like a t150 engine when you turn on the loud switch ,i have had her 16 years now and put 8000 trouble free miles ever one with a big grin.the problem lack of use this last couple of years modern petrol and amal carbs do not play nice together .amals made today are fine and the wassel copies are great but that argument is for over forums 

Spent some time in the garden yesterday but too cold to do much and the garage felt relatively warm in comparison so decided to fill and bleed the brakes.  I'd bought a cheap (£5.39) bleeding kit from Amazon comprising two different sized clear tubing, some pipe clips and a non-return valve.  Brake fluid is David Silver's.  I thought about pumping fluid in through the calliper bleed nipples using a large syringe but past experience had shown that fluid could leak out of the nipple thread so I went for the conventional approach, filled the reservoir and pumped gently to avoid any splashing.  Left calliper first, as it's a bit further from the reservoir, and the exiting fluid soon cleared of bubbles.  Similarly on the right and brake pressure came up quickly.  I left it overnight with the lever tied back to provide pressure and the reservoir cap loosely fitted so I'll look later today to see if that has improved lever feel.  That process has worked well for me on various bikes in that past though I've yet to see a clear explanation as to why it's effective; perhaps it simply allows the remaining tiny air bubbles to work their way up the lines and escape to the reservoir when the lever is released.  I'll report on the result.

Much warmer this week so decided to strip the old sealant from the inside of the fuel tank.  I could see that it was already peeling off in some place so was cautiously optimistic that the stripper (Frost) would remove it from all parts of the tank. I poured in about 80% of the bottle contents, swished it around on-and-off for about an hour, then left it overnight to do its work.  Poured out yesterday (23 Jan 24) a large amount of old brown sealant and discovered quite a few holes on both sides of the tank.  The holes had been covered with body filler - not quite a permanent fix, I feel!  I'll be replacing the old fuel tap so I used it as the stopper for the normal fuel exit point.



 I washed out the tank with warm soapy water, as per instructions, followed by lots more filling with cold water from the garden hose, shaking and draining out the rubbish.  Eventually I decided it was clean enough so put in and swirled around some phosphoric acid solution to kill any rust and prevent further forming on the newly exposed surfaces.  Left that for an hour or so the poured it out and dried out the inside of the tank with a hot air drier on a low setting.  

 The phosphoric acid solution is excellent for removing rust.  I'd stripped paint from the tank in preparation for subsequent painting and the bare metal gained a thin, orange sheen of rust overnight.  It was difficult to remove with wet and dry paper so I wiped it with the phosphoric acid which removed it all in about 5 minutes.  The acid is cunningly disguised as a garden product so is very easy to get hold of.  I've added a before and after photo of a rusty nail to show how effectively it removes rust, again in about 5 minutes, and it should leave a passivating layer on the surface to prevent further corrosion.  





I'm going to seal the holes in the tank with epoxy resin and GRP before sealing the inside with Frost Armourcoat.  I've used the latter on a few bikes with excellent results (I've no connection with the company) so hopefully all will be well..  Then to work on the side panels and seat fairing in preparation for painting. 

The clutch wouldn't release when I first tried it so it needed looking at.  I made a clutch centre-nut tool by grinding (badly) an old socket, removed the clutch.  The plates were stuck together but only lightly so took them out and cleaned them with acetone.  They looked to be in reasonable condition, as did the centre, basket, springs and release bearing so it all went back together and was reinstalled.  The oil pump drive chain was very slack (no tensioner) so I bought a new one from David Silver.  The new one is also slack, though not quite as much, so I suspect I needn't have changed it.  I took the opportunity to check that the balance shaft chain tensioner was working and it was, though it's close to the end of its adjustment range, I think.  I won't know then results of these activities until the engine is back in the frame and running so it's back to the tedious job of cleaning the engine!