Honda CB400F2 Restoration Part Six

Completion

I deliberately left the final assembly of the engine until it was safely in the frame. This has two advantages. Firstly the lump is easier to lift and secondly, the easily scratched outer covers can be put on when all the huffing and puffing is over.

Handlebars, exhaust clamps and brake pedal went off to Derby Platers for chroming, along with another tub of parts for zinc plating. I found another brake rod to replace the lost one, but the first one turned up in the bottom of their tank! The economics of chrome plating are borderline when new parts are still available. The improved quality swings it for me though, as the newly plated parts look like they will outlast the rest of the bike.

That lovely exhaust was a swine to put on. Two of the front pipes are welded to the collector-box and two are clamped to it. The two free pipes were reluctant to go together without fettling the holes in the collector, and even when they did, their clamps needed considerable persuasion to do their job. With the whole lot together it had to be dragged, kicking and screaming, into place. I thought I'd achieved a technical knockout once, but one of the clamps fouled the sump.

The nasty front brake was also reluctant to perform. A set of EBC brake pads from Mick Bull refused to fit without a struggle, and once in place were resistant to any kind of movement. After much fettling with emery cloth and files, the pad began to move in its bore, and I could actually push the 'bike around again.

Eventually it was time to start the engine. With a gallon of unleaded in the tank, it didn't take the electric starter long to get the beast running again. And did it purr like a Rolls Royce? No. It rattled like a bag of nails! I whipped off the rocker caps and checked the clearances, and watched for correct oil circulation.

Amid the mechanical clamour, one of the carbs was flooding, a plug cap was arcing across to the engine and the throttles were seriously out of sync. Another trip to Mick Bull fixed the sparks department with a set of new NGK caps. The carb would have to wait. The engine still wouldn't run smoothly, but with the ignition timing sorted, the whole job settled down. I was able to synchronise the carbs with my home-made manometer, but things still didn't seem silky smooth.

The engine was running OK, but still had a strange primary-drive sort of noise, and under power it felt harsh. I whipped off the sump, clutch and oil pump, but couldn't see or feel anything amiss. With the motor back together the noise was still present. I had replaced both cam and primary chains, so I convinced myself that the primary drive just needed bedding in.

Off went a letter to Carol Nash Insurance to have the Honda added to my policy. In two days the certificate had arrived and I busied myself with final adjustments until my weekend MoT test appointment. On the way to the test I had an opportunity to get a full appreciation of the noisy engine. It wasn't nice at all. After picking up the test certificate (yes it did pass!) and tax disk I took the bike gently home, and full of frustration, decided to strip the engine down again.

I was expecting some sort of crankshaft problem, but as the cases came apart everything looked perfect. I began a detailed inspection of the primary drive and gearbox. The gears and bearings were perfect and the chain was a brand new one. As I rolled it around in my hands, I noticed that one of the links was solid. On closer examination, two of the chain teeth were burred, preventing proper articulation of the chain.

Comparing the new chain with the original, I decided that the old one had plenty of life left and put it back in. (it was Saturday afternoon and I was eager to get the 'bike running) Everything was cleaned up and assembled with as much care as I could muster in the excitement. By 9 pm the bike was back together. I tentatively started the engine. It was cured! I quickly put on helmet and gloves and rode around to my mate Glyn's. It's 20 years since he rode his Velocette, but he shared my excitement and had a quick spin round his lawn.

Returning from a night time dash around the lanes, I noticed the oil light flickering. It was too dark to sort, so I went to bed with thoughts of more engine damage. I was up at six in the morning, and when I switched the ignition on the oil light stayed out when it should have been on. Strange. I whipped off the oil pressure switch and gave it a blow out. Back on the bike, it worked perfectly. Another crisis over.

By 8 am I was ready to ride my 'project' to Stanford Hall for the VMCC Founder's day rally. The afternoon was red hot, but the 'bike got many admiring glances from people who had, or always wanted, a 400-Four. One young woman said she would give anything to own one. (no, I didn't ask what!)

The 'bike ran well, although I rode it very gently bearing in mind the problems that had been cured at the 11th hour. The soaking we got going through Hinkley was just like old times. This week, I have been gradually sorting out the carburation. More importantly, I have been having some fun swinging the Honda around the country lanes.

No, I'm not going to tell you how much it all cost, suffice to say that the bills add up to more than the original purchase price....

Graham Curtis 30th September 1998

Thanks to the following suppliers who helped with the project

Tippetts Motors (Surbiton) Ltd
312-320 Ewel Road,
Tolworth,
Surbiton
Surrey KT8 7AW

Mick Bull Motorcycles
Unit 2,
36 Canal Street
Derby DE1 2RJ
Tel 01332 367470

David Silver Spares
Unit 14,
Masterlord Ind Estate
Station Road
Leiston
Suffolk
IP16 4JD
Tel 01728 833020

Derby Plating Services Ltd
148 Abbey Street
Derby
DE22 3SS
Tel 01332 382408