Ever since their introduction back in 1980, the Mantis range of tillers has been considered by some as a bit of a toy compared to the big and heavy tillers around today. In fact, initially, the model was shunned by men who thought it was a tool only for women to use around the garden!
How wrong they were, as now the Mantis tillers and cultivators are a popular choice for gardeners of all ages, men and women alike. These mini-dynamos can transform clumps of dirt into the perfect soil for planting in a very short time.
The lightest of their models is the Mantis 2-Cycle (or 2-stroke) 7920 model and that’s the one we’re going to be reviewing right here including a look at all its features, how well it performs in the real world and what accessories are available.Bottom line – if you’re hoping to find out everything you can about the 7920 Tiller, then you’ve come to the right place!
Mantis 7920 features
Here’s a quick look at the main features of this tiller just in case that’s all you want to know!
- 21.2cc 2-stroke engine
- Weighs just 20lbs
- Fast 240 rpm tine rotational speed
- Adjustable speed via throttle located on handlebar
- Maximum working depth of 10”
- 2 x forward direction rotating tines
- 9” tilling width
- 2 x tine positions for either tilling or cultivating/weeding
- Can be used to dig tree and shrub planting holes
- Solid worm gear transmission
- Manual pull recoil starting
- CARB compliant and EPA certified
- 5-year warranty for residential use. 2 years for commercial
- Lifetime warranty on tines breaking
- Moderate assembly required
- Soft grip folding ergonomic handles
- Tool-less air filter access
- Lots of accessories available inc. plow attachment and lawn dethatcher
How easy is it to assemble the 7920 rototiller/cultivator?
When you open the box up, you will find that there are quite a few parts needing to be assembled, but don’t worry, it’s quite straightforward.Here’s what you should have:
- Engine assembly including the worm gear transmission
- 2 x upper handles
- 2 x lower handles
- Handle brace
- Carry handle
- A pair of tines
- A bag of nuts, bolts, screws and retaining pins
- Small bottle of 2-cycle oil
- Operator’s/Parts manual
To put all this together will take most people around 30 minutes and you will just need two 7/16” wrenches to tighten things up.
What support and warranty does the Mantis tiller have?
Mantis has both an active customer service department that you can reach online or by phone as well as a huge dealer/service network so there will be no problem getting help if you need it.
The warranty provided is excellent with 5 years cover against defects when used for residential use, or 2 years when used commercially. Checking reviews and comments online it seems as though Mantis are pro-active in sorting out customer problems mostly which is good to know. They also provide a lifetime guarantee on the tines against breaking so that’s another bonus.
What size is the tiller and how heavy is it?
Mantis market this as the lightest rototiller available, which might not be true anymore with the electric tillers around now, but it certainly is one of the lightest gas-powered machines we’ve seen. It weighs just 20lbs which is incredibly light and makes you wonder if it can really do a good job without the weight to help it dig into the ground.
Happily, the way Mantis have designed the tiller makes it very effective which we will take a look at shortly in our section on its performance. What this does mean of course is that the 7920 is very easy to carry from one place to another so no more having to push it up a ramp to get it in the back of the car or pickup (and yes it will fit in a car which is useful to know!).
When fully assembled it’s around 53 inches from one end to the other and the engine/tine unit is 19 inches tall by 15.5 inches wide. The handles fold down for storage which cuts the length down to around 30 inches so it will not take up too much room at all.
What engine does the Mantis 7920 have in it?
The engine that powers this tiller is a 2-stroke 21.2cc model but other than that, there is not a lot of information available on it as it’s just listed as an OEM engine, i.e. manufactured by somebody else.
We’ve done some digging though and found that at the time of writing, the engine in this model is actually made by Echo and is their Little Wonder SV-5C/2 series. Echo are well known in the world of garden machinery and have a good reputation so this engine should stand up well over time.
However, we have found a handful of reports about the engine not starting well, particularly after storing it over the winter so be careful to follow the instructions for long term storage in the manual.
Being a 2-stroke engine, this model will need to run on a premixed gas/oil fuel which is mixed at the ratio of 50:1 gas to oil. You can use the oil included with the tiller to get you started and this must be mixed with unleaded gas with a rating of at least 89 octane. As a guide, to get the right mix, a 2.6-ounce bottle of two-cycle engine oil should be mixed with one gallon of gas.
The fuel tank on the 7920 holds 0.14 gallons (17 fl oz) and is translucent so you can see when you will need to top up. From our research, it looks as though you should get around 1.5 hours use out of a full tank so will not be having to stop to refuel that often.
Is this small tiller really able to dig my garden?
With nearly 40 years of use in the gardening world it would be unusual if the Mantis 2-stroke tiller did not do the job is was built for by now, so it should be no surprise that many customers are very happy with this versatile little tiller and cultivator.
Of course, with over ten years’ worth of online reviews, there are some not so happy customers out there which we will look at later, but these are mostly to do with starting issues anyway.
As for how it performs when tilling and cultivating, this lightweight but powerful machine is very capable and surprises many people when they come to use it. The bulk of the engine is positioned directly over the tines which it drives with a direct worm gear transmission, so no belts or chains involved. This means the tines have just the right weight on them to do what they need to, which is dig into and turn over the soil.
With a variable speed easily controlled through the throttle on the right-hand sure-grip handle, you will always be able to find the best speed for the conditions right up to the maximum tine speed of 240rpm. The curved tines themselves are designed to dig into the ground and not bounce around like other mini-tillers tend to do.
The trick behind how this is so effective for such a small machine is in the ‘vacuum cleaner’ action you adopt when using it. This means you push it back and forth rather than go in just one direction and usually, whilst walking backward. Pulling the tiller is what helps it to really dig into the ground and works so much better. It also means that you will not be walking on the freshly tilled earth which is a problem with the push only type tillers.
As we have mentioned earlier, the tines themselves can be swapped to go from the tilling position to the cultivating/weeding position. When set up for tilling, they will dig down up to 10” in depth, when changed over they only dig down 2-3” which makes it ideal for weeding and cultivating in the narrow spaces around a flower bed.
Another great use for the tiller is to dig a 10-12” deep planting hole for trees and shrubs. Just hold it in one place with a gentle rocking motion and it will dig down as far as the guard in no time at all. If you’re worried about breaking one of the tine prongs, Mantis have you covered as they are guaranteed against breaking in normal use.
If using this tiller for bigger jobs such as breaking new ground or digging up a lawn for example, then many people have found it can do the job eventually, but it may take quite a bit of work. You would probably be better off with one of the larger front or rear tine tillers depending on the size of the job. Check out our other tiller reviews for some recommendations.
The different jobs you can use this machine for make this one of the most useful tools you can have around the garden and with some of the great accessories available it can do even more than just tilling.
What accessories are available for the Mantis 7920 Rototiller?
Mantis supply a large number of attachments that can turn your trusty 7920 Tiller into a true multi-purpose garden tool. Here’s a list of the ones that fit this model:
- Planter/Furrower attachment – digs a deep 6” wide furrow perfect for lots of different root crops. Can even be used for cutting trenches to lay irrigation hoses etc.
- Plow attachment – plows uniform shallow or deep furrows in previously tilled soil.
- Wheel Set – attach this sturdy set of height adjustable wheels to make transporting even easier. Also, allows tiller to stand up for refueling etc. and provides additional stability when using certain attachments.
- Lawn Dethatcher attachment – a 15” wide set of sprung steel picks that quickly removes weeds and thatch that can prevent new grass from growing.
- Lawn Aerator attachment – aerates your lawn to allow better absorption of air, water, and nutrients. Use before overseeding or feeding for improved results.
- Crevice Cleaner attachment – removes dirt, weeds, and debris from cracks and joints on your paths, patios, and driveways.
- Border Edger – when attached to your Mantis this can cut neat and clean edges for your lawn where it meets flower beds and paths or driveways.
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What regular checks do I need to make on the Mantis tiller?
There is a whole section on maintenance in the manual, so reading that is a good place to get familiar with the tasks you will need to do to keep it running. To be honest, this is an easy machine to look after so there’s not a lot you have to do:Before each use:
- Inspect the air filter and clean or replace if necessary. Make sure it’s seated properly before tightening the cover.
- Check for loose nuts, bolts, and fasteners.
- Check fuel level. Top up if needed with clean fresh fuel.
- Check the spark plug. Make sure it’s seated properly and the connection is secure.
- Check tines for damage and make sure they are clear of weeds and debris.
- It’s a good idea once a year to check the transmission is greased properly and replace the fuel filter. The muffler screen will also need cleaning around the same time but apart from that, there’s not much else to do.
If the engine is running rough or not starting well then it may be time to make some adjustments on the carburetor. This just involves turning a couple of screws and there is a section in the manual that gives you all the details you need.
What safety equipment should I have when using the Mantis tiller?
With those sharp tines rotating at speeds of up to 240rpm, you do need to take note of the safety advice in the manual before attempting to use the machine. You will also need to get some items to help protect various parts of your body from accidents or damage. Here’s our list of recommendations;
- Eye protection is first on the list as stones can easily be flicked up towards the operators face. Some wide-view safety goggles will serve you well when using all sorts of power tools around the home.
- Next would be hearing protection as this is a 2-stroke machine and as such will be very noisy.
- A pair of good anti-vibration work gloves will help protect your hands from injury and the effects of handling a power tool over long periods of time.
- Reinforced toe capped boots would be next on the list as they will protect your feet from the blades when they’re moving at high speeds.
- Finally, make sure you are wearing suitable clothing and not something that could get caught up in the tines.
- DEWALT tough Coat hard coated lens provides tough protection against scratches
- DEWALT Xtra clear anti-fog lens coating provides tough protection against fogging
- SHRINK RESISTANT: These work gloves are made with synthetic leather, providing toughness, and helps to resist shrinking/hardening. Excellent for outdoor jobs where gloves may become wet.
- SNAG PROOF: Concealed inner stitching prevents these heavy duty work gloves from snagging on wood or metal.
What do customers think of the 7920 2-stroke tiller?
As we mentioned earlier, there is at least ten years’ worth of reviews available online for this model and as it’s a very popular tiller there are a lot to go through. So, you will be glad you don’t need to as we’ve already researched many of them.
Overall, most owners love their Mantis tiller, particularly how versatile it is and how well it works as both a tiller and cultivator. Many have had one for a number of years so they do seem to last a long time if looked after properly.
The biggest issue we’ve come across is one that many 2-stroke machine owners will be familiar with and that’s problems getting it started. That’s not to say everyone has this issue, most people find theirs always starts after a couple of pulls. We suggest you follow the guides in the manual (and they cover this in some detail) to make sure you do everything you can to avoid any problems and if you ever can’t get it started give Mantis customer support a call for advice.
What was, at the time, an innovative alternative to heavy and difficult to use tilling machines back in the 1980s, has stood the test of time and is now one of the most popular garden power tools we’ve come across.
With its range of accessories, great performance, versatile use and lightweight handling, the Mantis 7920 is thoroughly recommended. It’s great for anyone with a garden basically but comes into its own if you have anything larger than a small plot to look after.
Maybe not the best tool for demanding jobs such as breaking new ground on a large plot, it can still handle these if you have nothing else to use. Just be prepared to spend a bit longer doing it, although it definitely beats trying to do it all with a spade!
Last update on 2022-09-08 / Affiliate links / Images from Amazon Product Advertising API