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1964 Norton Dominator 88SS
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David Cooper bought his Dommi 88 in 1998. Since then he's been riding it and fettling it and has covered over 10,000 miles. So what's his opinion of the bike after nearly a decade of ownership?

When we asked David Cooper for some notes about his Norton Dommi for our RealWheels article (it appeared in RC41, the September 07 issue of the magazine), he couldn't resist giving us acres more information than we had space for. That's the problem with print and paper - a finite amount of room! Luckily, there's always room for one more on top here, so now you can read David's full story…

In 1961 a 500cc Norton was the first pushrod twin to achieve a 100mph lap speed at the Isle of Man. It was 1969 before 750cc Triumphs caught up. This is not that bike…

My bike had been kept in a heated garage and only done about 5000 miles since a complete rebuild about 10 years before I bought it. The owner said his bus pass was more useful than a Norton in London! It came with just one 26mm concentric carb, which did nothing for performance. On my first proper run the vibration reached the frequency of my eyeballs at 60mph, and they vibrated so much I couldn't see where I was going. It turned out the head steady wasn't tight - it could have wrecked the frame!

Non-matching front and rear mudguards? Looks a bit odd to me. 1964 Norton Dominator 88SS

I replaced the 26mm carb with a 28mm version (3½ chromed slides, 220 main jets, needles at middle setting), and then added another. I cannot find much fault with twin carburetors - the occasional overtaking blast up hill is much more fun if carburetion is correct. Overheating when too lean on one carburetor caused the biggest problem, but that was my fault. I think the biggest danger with two carbs is that if one is correct it can disguise a serious problem with the other. Cost is another issue if you fit two non-standard carbs - every new throttle slide and main jet cost twice as much money. But I set it up on one, and the settings are the same for two. Now it's fine up and (allegedly) beyond the motorway legal limit, but is best on the winding lanes and ordinary A- and B-roads it was designed for.

In February 2000 the magneto flooded with oil when the breather got blocked with condensation emulsion. I stripped and cleaned it, but then it wouldn't start when hot. I solved it the quick and lazy way with a Lucas RITA conversion, bolted to the back of the battery box. It's far easier to adjust the timing (by the roadside if I feel the need). The RITA has its own auto-advance, so I took the balance weight springs out of my auto advance so it flies to full advance as soon as it turns.

However, I wish I'd been patient enough to spend the money on reconditioning the nice Competition Mag that came with the bike. The K2FC was just as good as electronic, before it actually failed me - and it doesn't rely on battery charging.

A Boyer Power Box (on rubber mounts under the tool tray) looks after the electrics, and I've fitted a full flow oil filter (shame about the looping pipes) and modern tyres. I had to replace a loose valve guide with an oversize one I turned down from the larger 850 Commando version. I added an oil feed pipe valve with cut-out switch (courtesy of an advert in the Jampot) so I don't worry about wet sumping (as long as I remember to switch it off).

Oil feed pipe valve is the red thing above the gear change shaft. 1964 Norton Dominator 88SS

Nortons already have hard valve seats, but the previous owner fitted replacements anyway -- I don't know why. I usually run on standard unleaded, but treat it to Shell Optimax for special occasions. I think it makes the engine a bit more flexible. I don't like to leave Optimax in the carbs if the bike is to stand for a while, because it leaves a nasty brown glue-like residue when it evaporates. I measured the compression ratio at about 8.5:1. Some have 9.5:1 instead, and they'd probably need the good stuff.

I made a rack from copper central heating pipe, and it's very useful and not too obtrusive. I need my rear view mirror in London, and indicators would be handy.

Brunel would be proud... 1964 Norton Dominator 88SS

It came with Commando twin leading shoe front brake. This was savage when cold and poor when warm. New shoes from Russell Motors fixed that. I took no notice of the book instructions about adjusting the tie link. Instead, I fitted the shoes to the back plate and carefully adjusted the link when the plate was off the bike so that it took up both shoes at the same time. Then I fitted the spindle nut finger tight, and then fully tight whilst holding the brake levers on hard. Brakes are good now that it's bedded in.

I've tried everything to stop the primary case from leaking. Silicone - don't do it - you struggle to get the case off, and then you can't clean the residue. Blue Hylomar was OK for a short time, but dries out and cracks into blobs. A new rubber band is not as well made as the old one. Now I've changed the engine and gearbox oil seals, and maybe it's better. But I may be wrong.

All the work has maybe cost £1000 - I keep receipts, but I dare not add them up! But over a seven year period the bike has got slightly better all the time, and most of the modifications have been voluntary. Apart from the primary case drips, the design is pretty sound and reliable, handling is legendary, and vibration from 500cc is no problem. Fat, ribbed Commando grips stop the throttle from unwinding in my gloves on a fast run, and I use electric cable ties tight round the throttle grip to stop it unwinding from the bars.

I'm using a genuine Norton silencer on Armours' siamezed pipes. The Norton box is a bit quieter than my spare Armours' box, and I think it makes the engine quicker and smoother. Also air filters help to cut induction noise, massively reduce engine wear, do not affect performance - and a quieter bike goes quicker in my experience. Something about my mechanical sympathy, I suppose; by far my best aid to performance is a pair of ear plugs. If I can't hear an engine in pain, I am much more willing to thrash it!

Siamezed pipes were an original option, and I thought they slightly improved mid-range when I fitted them, but I think vibration also increased. Maybe it's because their internal gas smoothness is not brilliant. They make maintenance much easier.

It does about 65mpg last time I checked; it's certainly a lot better than my car!

Dominator stuff on

Now (I hope) I seem to have a quick reliable bike (I never like saying that too loud…). It's never let me down on the road. I always carry a few tools and puncture outfit for moral support! There's no real mechanical weaknesses in Norton design - for instance, the fantastic gearbox makes every quick change a pleasure, and it handles better than I can ride it.

It looks good and it sounds good. I do everything I can on the bike myself. If you've never touched an engine then read a few books and get on with it!

40 years of development... 1964 Norton Dominator 88SS (right) with 1926 Model 18 (left) and 1932 Model 30 (centre)


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