Tips for a top T140
Andy Orton has restored over thirty T140s. He tells Bob Dixon exactly what to check out when looking for one – and which are the best to buy
Andy Orton’s workshop has a charming air of barely-contained chaos. It’s as if a disgruntled Machine Mart customer detonated an improvised explosive device in one of their smaller branches. Curious tools and interesting bits sprout all around me, but don’t be fooled by the mayhem – I’ve known Andy long enough to see dozens of phenomenally high quality restorations emerge from this modest space.
Andy’s taste in bikes is eclectic; he’s owned an extraordinary variety of machinery since he began motorcycling in his teens. His restoration experience covers Triumphs, Nortons, BSAS, Ducatis, Royal Enfields, Sunbeams, Vincents, Harleys and Laverdas. When I had a nose around his storage facility, I saw a pre-war works Sunbeam, a Norton Inter and a gorgeous Commando desert sled. Like I said, eclectic.
However, during the past few years Andy has concentrated on 750cc Triumph Bonnies and Tigers. “Their main appeal is they’re cheap and plentiful, especially when the shipping containers have just landed from the US and the market is temporarily flooded with them,” he says. Over a cuppa in the workshop, I pick his brains about the pros and cons of buying and renovating a T140 and its sister bike, the TR7... Classic Bike What are the most important things for a buyer to look out for when buying a 750 Bonnie or a Tiger?
Andy Orton Well, if it’s a project, look for the most complete bike you can find, make sure it has compression and all gears can be selected. The latter is quite important because if they’re left outside for any length of time, water can track down the outer clutch cable and fill the gearbox with water. This is bad news.
Never buy a bike that is missing a kickstart, gearlever or chain – something might be seriously wrong. I always try to buy a bike with nice chrome on the wheels; even though I do my own wheel building, it’s still an expensive exercise, so it helps if the wheels are in good condition to start with. Don’t be put off by a little surface rust; the original chrome on both the Jones and the Dunlop rims fitted by Triumph is good quality and will often polish up nicely. Generally speaking just buy the best bike you can afford. American imports are frequently low mileage and unmolested.
If you’re looking at a bike to ride straight away, the normal rules apply. Have a good look at the bike and its general condition – particularly the wiring, because if it’s going to break down, it’s usually some sort of electrical issue. The newest Bonnie or Tiger you’re going to be looking at will be 40 years old and the wiring degrades.
When I’m rebuilding a bike, one of the first things to go in the bin is the loom. I build them from scratch – the
only thing I keep is the alternator and the switches. I also replace coils and leads, and fit a modern regulator/rectifier and electronic ignition if this hasn’t already been done.
The oil light should go out just by one swing of the kickstart – and ideally should stay off for a second or two. The oil pump is simple and effective; it rarely gives trouble, but can become inefficient if the tiny ball bearings inside aren’t seating properly. I usually buy non-running bikes and before I fire them up I always check the pump for wear, clean it out and re-seat the balls in the bottom of the pump, and clean the pressure release valve.
Also, I always change the crankshaft oil seal in the timing cover. It’s a simple job, but very important. If, by some miracle, the bike I’m buying is running, I still do this – along with checking and cleaning the gauze filters in the sump and frame. Look for new gaskets around the engine; if any are visible ask what work has been done.
When the bike is running, listen to the engine. They’re usually reasonably smooth and quiet. Look for oil leaks, particularly around the pushrod tubes – it’s a top-end off job to fix. Check it doesn’t smoke; they can smoke a bit when on the side stand, as the oil in the sump is biased to the left-hand pot, but it should clear when the bike is upright. CB: Which model would you say is the most desirable of the T140/TR7 model range?
AO: Obviously this is subjective, but the T140D is always popular. The export-spec Jubilee bike is sought after
and then there are the rarities like the eight-valve TSS and the dubiously styled TSX. The Executive is desirable to some and also quite rare. The rarest and potentially most collectable of all has to be the Tiger Trail, particularly in 650 form, of which there are only six known bikes.
CB: Which is the best value model of the five-speed 750s?
AO: That would be a Uk-spec Tiger, say ’73-’74 with a drum on the back. It depends whether you want a twin-carb Bonneville or a single-carb Tiger. The thing is, Amal carbs are not really known for their high quality, so it all comes down to whether you want a bike with two bad carbs or just the one!
CB: Are there any particular weak points a prospective purchaser should look out for?
AO: Not really. It’s well documented that the frames can crack at the bottom of the oil tank, but my own experience doesn’t bear this out. I’ve restored more than 30 oil-in-frame bikes and never seen one with this problem.
CB: What would be the cost for a complete engine overhaul?
AO: I honestly don’t know – all the bikes I’ve built have seldom needed any attention to the bottom end because they’re very strong. I do the top ends every time – a gasket set is about £35, that includes all the seals for the pushrod tubes; I always put rings in while it’s apart, these are thirty quid-ish; if it needs a rebore, a piston kit is about £120 and it’s fifty quid a pot to get it bored and honed. Valve guides are around a tenner each if they need doing.
CB: What’s a realistic budget for a T140 or a TR7?
AO: For a project, I pay £3000-3500. You could buy a decent, useable runner for between £4500-5000. Restored bikes in mint condition will be £6000 upwards, depending on model and spec. A Tiger is usually cheaper than a Bonneville.
CB: Are there any must-have tools a T140/TR7 owner should invest in?
AO: A clutch spring adjustment tool is useful, as is a puller for the clutch hub. There are various pullers for different things, I have them all, but the average owner wouldn’t use them. Just buy special tools when they’re needed.
CB: What’s the most surprising thing you’ve ever come across in a restoration?
AO: I remember discovering the handlebars of an Indian army Royal Enfield had been stuffed with marijuana! In terms of T140s, I always enjoy discovering the fault which originally led to the bike being taken off the road – mostly something very simple.