MZ MASTIFF 660 (1998 - 2006) Review

At a glance

Owners' reliability rating: 4.3 out of 5 (4.3/5)
Annual servicing cost: £100
Power: 50 bhp
Seat height: Medium (32.7 in / 830 mm)
Weight: Low (386 lbs / 175 kg)

Overall rating

Next up: Ride & brakes
4 out of 5 (4/5)

The MZ Mastiff is solidly-built and with looks that could launch nuclear missiles, “aggressive” just about sums up the Mastiff. However, it’s a great road bike, easy and huge fun to ride. Perfect pulling power for townies or twisties and tough enough to withstand abuse and the elements. Pleasantly unusual, too. It’s a goodie.

Ride quality & brakes

Next up: Engine
4 out of 5 (4/5)

With a reasonable seat height, great geometry and good grip, the MZ Mastiff holds the road well, even at crazy lean angles, which it loves. It may look chunky but it’s made for throwing around. The gearbox is strong: use it along with some serious throttle and you really will be laughing. Suspension’s slightly soft but it copes.


Next up: Reliability
5 out of 5 (5/5)

Like its Baghira cousins (and a number of other manufacturers’ machines), the MZ Mastiff takes its engine from Yamaha’s XT660 (the carbed version). Tough, reliable and durable, it offers plenty of low down torque for roaring around bends or tearing up rush hour traffic. At higher speeds it wheezes a bit but, for fun or commuting, it’s a perfect old thumper.

Reliability & build quality

Next up: Value
5 out of 5 (5/5)

The MZ Mastiff is incredibly tough, plastic body parts by Acerbis, proven engine by Yamaha, WP shock and Marzocchi forks… This is an A-list team effort if ever there was one. The Mastiff’s carefully and brilliantly put together, boasting excellent reliability and quality that puts bigger manufacturers to shame.

Value vs rivals

Next up: Equipment
4 out of 5 (4/5)

Whilst the looks put some people off, those who dare get the last laugh. The MZ Mastiff, as its name implies, is a strong, reliable beast which will weather many a storm. It may not hold its value as well as its starrier KTM counterparts but it’s almost as good and costs a lot less to buy. Fuel consumption and  insurance make it cheap to run. Find an MZ Mastiff for sale.


4 out of 5 (4/5)

The MZ Mastiff's a meaty bugger with an aggressive, bull-bar style front end and twin headlamps (which work rather well). Large, analogue clocks and a basic display of lights make up the dash while wide mirrors work brilliantly. The front brake lacks initial bite but it gets there eventually; the rear’s almost too good. Both have braided lines as standard. The seat’s a bit crippling.


Engine size 659cc
Engine type 5v single cylinder, 5 gears
Frame type Steel cradle
Fuel capacity 12.5 litres
Seat height 830mm
Bike weight 175kg
Front suspension N/a
Rear suspension Preload and rebound
Front brake 298mm disc
Rear brake 245mm disc
Front tyre size 120/60 x 17
Rear tyre size 150/60 x 17

Mpg, costs & insurance

Average fuel consumption 50 mpg
Annual road tax £111
Annual service cost £100
New price -
Used price -
Insurance group 9 of 17
How much to insure?
Warranty term Two year unlimited mileage

Top speed & performance

Max power 50 bhp
Max torque 42 ft-lb
Top speed 103 mph
1/4 mile acceleration 14.3 secs
Tank range 138 miles

Model history & versions

Model history

1998: MZ Mastiff launched as a supermoto alongside the MZ Baghira enduro bike. Together, they helped the marque’s range become more competitive in the market than it had been and, consequently, helped build it a stronger (and, since then, enduring) reputation than it had previously enjoyed.

Other versions

None, although fellow family member, the MZ Baghira Street Moto, is very similar in spec (bar different tyres, weight, seat height and styling).

Owners' reviews for the MZ MASTIFF 660 (1998 - 2006)

3 owners have reviewed their MZ MASTIFF 660 (1998 - 2006) and rated it in a number of areas. Read what they have to say and what they like and dislike about the bike below.

Review your MZ MASTIFF 660 (1998 - 2006)

Summary of owners' reviews

Overall rating: 4.7 out of 5 (4.7/5)
Ride quality & brakes: 4.3 out of 5 (4.3/5)
Engine: 4.7 out of 5 (4.7/5)
Reliability & build quality: 4.3 out of 5 (4.3/5)
Value vs rivals: 5 out of 5 (5/5)
Equipment: 3 out of 5 (3/5)
Annual servicing cost: £100
5 out of 5 Mastiff by name massive fun by nature
04 July 2023 by Sparkie Al

Year: 2006

Annual servicing cost: £100

FUN with a capital F. Wanted something for a ride out on sunny Sundays that was light to move around, simple to work on, no electronic gizmo's, fairly tall seat height as i am 6 ft 3 and fun. Didn't want a rocket ship but something that would keep pace with modern traffic but still had acceleration when required, but not so that keeping hold of your licence was nigh on impossible. The Mastiff does all this and more, massive grin every time i put my helmet on, as i know i am going to have fun but not scare myself silly, The thing corners like its on rails, amazing levels of corner angles can be achieved, easy to run rings round modern stuff on the twisty roads, granted they will fly past you on the straights but anyone can go fast in a straight line. KTM super-moto fun for half the price and as its a Yamaha 660 engine parts are available not that its ever broken down on me. Don,t be put off my the MZ badge its a hoot to ride.

Ride quality & brakes 4 out of 5

Brakes are awesome, plus as it's a single cylinder has loads of engine breaking to help slow you down. So easy to ride and not need to touch breaks when riding on A & B roads when the engine breaking comes into it's own. Seat gives you numb bum after an hour in the saddle, but hey you don't buy a Mastiff for touring on. Can get a bit of vibration through the bars & pegs above 5000 rpm but then your doing over 80 any way.

Engine 5 out of 5

Yamaha 660 enough said. Will happily cruise all day at 80, returns at least 50 mpg, has enough grunt to over take traffic. Being a single you don't need to rev the nuts off it, mine has an after market Predator silencer on it, (silencer not the correct word as it makes for a glorious exhaust note, & pops and bangs on the over run).

Reliability & build quality 5 out of 5

Never let me down, well engineered only ever needs basic servicing. Starts on the button every time and stops on a sixpence. Cheap as chips and you don't need to be a rocket scientist to work on it.

Value vs rivals 5 out of 5

Oil & filters once a year plus new plug and that's it. Being dry sump its a bit of a faff as it's oil is stored in the frame, plus access to the plug is a bit of a pain but a couple of hours is all it takes and anyone with basic engineering knowledge can carry out the work at home.

Equipment 3 out of 5

Mines bog standard except for the silencer and Scot oiler, so rather minimalist on the equipment side, but makes up for it in the grin factor.

Buying experience: Bought private for under £2K with 16K miles on it.

5 out of 5 More fun than a superbike!
26 October 2011 by bod1969

Handling on this thing is sublime and the deceptively punchy engine gets you from A to B quicker than any bike I've ridden. I'm talking in the real world here with potholes, rain and traffic, the places my ZX9R faltered. Having been a courier years ago this is the first bike that leaves me grinning from ear to ear in over a decade. It ranks right up there with the RG500, TDR250 and my race tuned ZX9R C1 in the lunacy stakes, as its harmless commuting often turns into bad boy behaviour when the 2nd carb kicks in. The point is its usable and forgiving, as it soaks up speedbumps and ignores our crappy road surfaces, I swear its just as good in the wet too. Switches are problem as are the Grimeca brakes which are a pain to bleed, just get some Brembo master cylinders an life becomes perfect. Parts are hard to get as no proper dealers exist but I always get what I need off ebay or Grahams of Taunton within a day or two. R1 brakes fit straight on as does an R1 front end. Dont do over 50 miles on a motorway or you will regret it, the Mastiff simply isnt made for that but you will ride A and B roads like never before or as long as you can keep your licence. £75/year insurance(Im 42)and 60mpg (turn the idle speed down) and whose laughing at MZ now? Certainly not the guys in your mirrors!

Ride quality & brakes 5 out of 5
Engine 5 out of 5
Reliability & build quality 4 out of 5
Value vs rivals 5 out of 5
Equipment 3 out of 5
4 out of 5 mastiff for the aged !
23 April 2008 by alberttdm

Needed a replacment for my get to work bike a humble c90, as car drivers apeared to be useing me for a slow moving target !also have a bandit 12 for touring etc>looked at the specs/prices of this type of bike-mastiff wins hands,s not a wheelie merchant,but off the line it really flys cheep to run insure and handles very well.Put another way ,look at an xt660 of same year then add wp shock etc to cost.the important thing is its FUN !!! try one and see.

Ride quality & brakes 4 out of 5
Engine 4 out of 5
Reliability & build quality 4 out of 5
Value vs rivals 5 out of 5
Equipment 3 out of 5
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