Miniplane Top 80


by Had Robinson
updated February 8, 2022

A. Troubleshooting your engine – Here are the steps and information to solve problems with your paramotor.

B. Top 80 parts diagrams Mecafly  WG carb

C. Miniplane-USA info  Miniplane Italy info  Info from Mark Kubisch

Gear and wheel pullers should not be used when working with aluminum engine parts except under special circumstances.

Before putting any paramotor in service, new or used, CHECK THE TORQUE of the head nuts

SPECIFICATIONS – gaps, torque values, dimensions, timing value, and maintenance intervals for the Top 80

Air box – the air box usually has an internal air filter.  It must *NOT* be saturated with oil.  It is unnecessary and can restrict air flow into the engine.  Periodically wash the filter in hot soapy water, as needed.

Air filter – see "Air box" above

AVGAS – see "Fuel & oil specifications" below.  We no longer recommend using AVGAS because of lead fouling problems.

Bearing condition – shat condition are the bearings in my engine?  Which one is the most likely to fail first?

Bearing replacement and case disassembly and assembly – here is how to replace the main crankshaft bearings and seals

Breaking in a new or rebuilt engine – this is critical that it be done correctly if you want your engine to have a long life.

Bubbles in the fuel lines

Carburetor – Walbro WG information, adjustment, & repair  Important notice: The WG and Husqvarna 503282001 are identical.  The WG is no longer in open distribution except through Husqvarna.

Carburetor drips/leaks – see "Drips" below

Case assembly – see "Bearing replacement and case assembly" above

Choke – what does it do?  Why have it?

Choke fault – the latest Top 80 model has a defective choke setup which must be fixed in order to start the engine when it is cold.

CHT – see "Cylinder head temperature gauge" below

Clunk – see "Fuel filter" below

Clutch – complete information on the Top 80 clutch.  Also the "Redrive" section below

Clutch alignment

Clutch bearing replacement – it is done in the same manner as for the main bearings (see Bearing replacement... above).  Steel does not expand as much as aluminum so a press MUST be used to install the clutch bearings.  They will not just "clink" into place.

Cold weather operations – unfortunately, the WG carburetor and, to a lessor extent, the WB are sensitive to both high altitude and/or cold weather operations.

Connecting rod – see "Rebuilding a paramotor" below for info on this part including when it should be replaced (which must include the entire crankshaft).

Cooling box fin breakage – see "Metal fatigue" below

Cooling box – removal and assembly – see cooling box removal in "setting the timing on paramotors" page

Cooling fan – it is integral to the cooling box and is removed with it.  See cooling box removal

Cooling shroud – when replacing the cooling shroud, put copious amounts of RTV between the large washers on the cylinder head studs and shroud.  This will help cut down the wear of the shroud at these points due to severe engine vibration.  Order of hardware: large washer, shroud, plastic washer, small metal washer, nut

Compression check – one of the best ways to quickly check the overall health of an engine.

Crankcase external pulse port – see "External pulse port installation" below

Crankcase leaks

Crankcase replacement – see "Rebuilding a paramotor" below.  The paramotor must be completely disassembled.

Cruise control – not a good idea and here is why.

Cylinder gasket installation – see "Squish" below

Cylinder head & piston notes – when doing the 100 hour required top end maintenance

Cylinder head O ring gasket installation – NEVER REUSE A CYLINDER HEAD O RING

Cylinder head temperature gauge – not having a CHT is like driving a car without any gauges or warning lights. Most of the time you don't need them.... 

Cylinder honing – cylinders that are lightly worn can be honed and the piston ring replaced without having to replace the cylinder.  We do not recommend doing this because cylinders are inexpensive compared to the having a shop do it + shipping.

Cylinder piston sizes – this is a table of the piston sizes (letters) for the corresponding cylinder diameter after boring or honing.

Cylinder replacement, new – see "Determining the correct size of gasket to use" and follow the directions.  If a compression check gives a value less than 90% of specifications, replace the cylinder including the piston and ring.  Also, see "rebuilding 2-cycle engines" below for more general info.  Instead of replacement, pilots may have their cylinders bored and honed at this shop (RB Designs).  You will have to measure the cylinder diameter with a micrometer, determine the correct oversized piston needed, get it from Miniplane-USA, and send it all in to RB Designs.

Cylinder squish – see "Squish" below

De-carbonizing a two stroke engine – Alex Varv shows how to do it without removing the cylinder.  However, I do not recommend using any sealant between the cylinder and cylinder head.  I have never had a  head leak when the "O" ring is new and installed properly.  The exhaust port should also be cleaned at the same time.

Detonation – this is a serious problem caused by cheap gasoline while running engines near sea level.  Use premium ethanol-free fuel whenever possible in order to prevent this problem.  Incorrect ignition timing and too little cylinder squish can also cause detonation.

Disassembly of the Top 80 – see "Engine overhaul" below

Drips – two stroke engine carburetors drip/leak fuel by design but it should not be excessive.

Engine mounts – see "Mounts, engine" below

Electrical troubleshooting – see "Ignition troubleshooting" below

Engine leaks – see "Leaks of the engine, exhaust, and redrive" below

Engine rebuild – see "Rebuilding 2-cycle engines" below

Engine stall – see "Stall" below

Exhaust – also see the "Muffler" section below

Exhaust leaks

Exhaust port cleaning – after many hours the inside of the exhaust port and the manifold can have substantial deposits of carbon and/or lead phosphate/monoxide.

Exhaust port gasket installation

Exhaust port spring installation – the exhaust nuts must be tightened precisely against the spring and NOT overtightened.

Exhaust port leaks – see "Redrive, carb, crankcase, and exhaust leaks" below

Exhaust port repair tool – if the cylinder exhaust port is damaged, this tool can repair it.  Here is how to do it.

Exhaust port stud installation

Exhaust springs – how to remove and install them correctly.  Note: for a while Miniplane supplied defective springs which constantly broke.

Exhaust system holes & leaks

External pulse port installation – needed for some accessories and the FSM

Fading – see "Performance Issues" below

Finger screw and starter pawl replacement

Finger screw modification – every time the cooling fan is removed, the finger screws should be replaced ($$$).  Here is how to re-use them.

Flywheel removal

Frame cracking – see "Metal fatigue" below

Fuel filter – what kind/type to use?  If you choose poorly, the engine will also run poorly, if at all.  Removal and installation tips.  The fuel system MUST be purged of old fuel and air when changing out the fuel filter.

Fuel line replacement – it is not as simple as most think....

Fuel line size & type

Fuel mixed? – is there oil in the gasoline?

Fuel & oil specifications – 2% (50:1) full synthetic oil with premium ethanol-free gasoline.

Fuel system leaks – see also "Leaks of the engine" below

Fuel system modification – the FSM dramatically fixes fuel starvation and most performance issues (still in the test phase)

Fuel system quick test – see the "Quick fuel system test"

Fuel system test – a more thorough test of the fuel system.

Fuel tank cap leaks – how to find and fix the factory defects which make it hard to prime the fuel system.

Gearbox – see "redrive" below

Gudgeon pin circlips – see "Piston wrist pin circlips" below

Harness adjustment

Harness strap repair – thinner pilots routinely have the buckles break.  Here is how to easily fix the problem.

High altitude use – see the WG carburetor page

Hub – see "Propeller hub info, removal & installation" below

Ignition coil check – see "Electrical troubleshooting" below

Ignition coil, flywheel gap adjustment

Ignition coil, loose inner coil – when it becomes loose/detached from the iron core and how to repair it

Ignition coil replacement

Ignition coil, secondary wire replacement – this is the most common point of failure in the ignition system in all but the newest models

Ignition coil secondary wire troubleshooting – see "Electrical troubleshooting" below

Ignition timing – how to accurately set the timing on most paramotors

Ignition timing check

Ignition troubleshooting

Kill switch problems

Knocking – see "Detonation" above

Leaks, carburetor – see "Drips" above

Leaks of the engine, exhaust system, and redrive (also, see "Fuel system leaks" above)

Leaks of the reed valve – see "Reed valve" below

Main bearing seals – if they leak slightly after 100's of hours of use, it only causes a little mess and is to be expected.  Leave them alone.

Maintenance info & intervals

Manual, owners – see "Owners manual" below

Metal fatigue – pilots who put 100's of hours on any paramotor must keep an eye out for this hazardous and hard to see problem.

Midrange roughness or four cycling – most paramotors run poorly in the midrange due to a rich air/fuel mixture, the range that we spend most of our time flying in.  It can be fixed but not completely unless an FSM is installed.

Miniplane frame information – options, sizes, side stick lengths, etc.

Mounts, rubber (engine) – here is a way to quickly check them.  These are normal consumable parts that fail with use.

Muffler oil leaks – see "Exhaust system O-ring leaks" above

Muffler problems – rarely, the muffler can get clogged (from Bill Stoll)

Muffler repair

Net stringing – see "Safety net stringing" below

Net repair – see "Safety net repair" below

Net wear – see "Safety net wear" below

Oil leaks – see "Redrive, carb, crankcase, and exhaust leaks" below

Oil specifications for the Top 80 – see "Fuel & oil specifications" above

Overhaul – see "Rebuilding a paramotor" below

Overheating – this will destroy an engine.  What causes it?  How is it prevented?

Owners manual – from Miniplane, difficult to follow, poor English, badly organized :(

Packing the Top 80 for shipment  (if you wish to just ship an engine, follow these instructions)

Performance issues – does your engine run poorly, if at all?

Performance tuning – most paramotors run poorly in the midrange due to a rich air/fuel mixture, the range that we spend most of our time flying in.

Piston circlips (wrist pin springs) – never reuse them.  See this video for how to remove or install them.  Stuff a rag in the crankcase so in case you drop one, it does not disappear in the guts of the crankshaft.  Be certain that the circlip is completely seated and installed with the circlip opening facing down.  This helps insure that the clips do not come out.

Piston failure – This page from Madsen's (a chainsaw dealer) gives many maintenance and repair tips on 2 stroke engines including the piston.  Paramotors are more like chainsaws and motorcycle racing engines than any other.  Paramotors use carburetors from obsolete chainsaw.

Piston replacement – it is not advisable to attempt this without intermediate mechanical skills.  See "Rebuilding a paramotor" below.

Piston Ring – how to remove and install it and tell if it needs replacement.

Piston sizes – see "Cylinder piston sizes" above

Power loss – see "Performance issues" above

Preheat system of air entering the carburetor

Priming the fuel system on a paramotor – see "Starting your paramotor" below

Propeller hub info, removal, & installation – note: A propeller strike that damages the propeller will likely bend the hub and cause vibration.

Propeller info – General information including how to correctly attach and repair it

Propeller bolt shear problems – see "Propeller Info" above.  Also, see "T-Nut Milling Tool" below.

Propeller shaft seal replacement – see "Redrive propeller shaft seal replacement" below

Pulley, starter – see "Starter pulley" below

Purging the system of fuel – it must be done if a paramotor is to be stored for more than a few weeks, especially if you are using ethanol fuels.

Pulse port, external – see "External pulse port installation" above

Rebuilding a paramotor – includes disassembly and assembly of the major parts of the engine e.g. flywheel, cooling fan, carburetor, etc.

Redrive alignment

Redrive clutch – see "clutch" above.  The redrive contains a clutch and a set of reduction gears.

Redrive leaks

Redrive propeller hub removal and installation – see "Propeller hub and removal installation" above

Redrive removal and installation – see the clutch page.

Redrive fill plug problems – see "Leaks of the engine, exhaust, and redrive" above.  The plug can become clogged and cause leaks in the redrive

Redrive leaks

Redrive gear noise – it can be safely ignored.  The noise will be more pronounced when the prop is rotated in one direction vs. the other.

Redrive lubricant – info on the correct type, quantity, and how to change.

Redrive mounting and alignment – see the clutch page.

Redrive mounting stud failure – stainless steel is inferior to class 12.9 steel hardware.  The former will fail on engines with many hours.

Redrive propeller shaft seal replacement – here is how to quickly and easily replace the seal without taking the redrive apart.

Redrive rebuild

Redrive seal replacement – see "Propeller shaft seal replacement" above

Reed valve

Rich running condition – see "Performance tuning" above

RTV – e.g. Permatex Blue or Ultra Grey.  Used to seal case halves, some gaskets, and surfaces.  Apply with a clean finger.  Forget the spout that comes with the tube.  It is useless.  Use Ultra Grey for sealing surfaces that may become hot, like the exhaust flange gasket.  More sealant is not better.  It is not as simple as most think.

Rubber mounts – see "Mounts, rubber" above

Safety net new installation or replacement

Safety net wear – how to minimize wear and tear on the safety net

Sand damage – it is fun to fly at the beach but taking off in the sand one time is worse than 100 hours of normal running time because sand gets into the engine.  The fine grit can also cause the piston ring to stick, causing more damage.  Always launch from grass.  If it is wet, all the better.

Secondary wire replacement – see "Ignition coil, secondary wire replacement" above.

Secondary wire troubleshooting – see "Electrical troubleshooting" above

Sidestick mount protection – the sidebars and sidestick mounts will grind away on each other.  Here is a fix.

Smoke systems – pilots must be extremely cautious when installing smoke systems on any 2 stroke engine with a tuned exhaust and here is why.

Spark plug boot replacement – it is not that simple if you want it to last and work well.

Spark plug info – meaning of the NGK part numbers

Spark plug installation – do not waste time troubleshooting an engine unless the spark plug is new.  It must be gapped and installed correctly.

Spark plug reading – how to do it.  A cylinder head temperature gauge (CHT) is essential and will confirm what the observed condition of the spark plug.  Also see "Electrical troubleshooting" above.

Spark plug specifications – go to "SPECIFICATIONS" below

SPECIFICATIONS – dimensions, torque values, maintenance intervals, and other useful information

Springs, muffler – see "Exhaust system springs" above

Squish – pilots must get the correct size cylinder gasket to prevent overheating, detonation (knock), and engine damage.

Stall – going to full throttle, the engine stalls.  Or, the pilot bends over and the engine stalls.  What are the causes?

Starter – see "Finger screw and starter pawl installation and removal" above

Starter cord – how to replace it.  See Mark Kubisch's notes below

Starter pawl and finger screw installation – see "Finger screw and starter pawl installation and removal" above

Starter pulley – the OEM Viadana pulley quickly wears out and fails.  Here is the solution...

Starter replacement cord – this cord is 100% Dyneema line and is superior to the OEM cord.

Starter – how to properly disassemble and lubricate the starter and help it last longer.

Starter kick – when stopping the engine, the pawls engage the starter and kick the starter assembly hard.  Here is how to prevent this.

Starting your paramotor – start your engine the first pull, every time.  Here is the secret on how to correctly prime the carburetor.

Storage – if you are storing your paramotor for more than a few weeks, PURGE THE FUEL SYSTEM.

Stress cracking of the engine frame and other components – see "Mounts, rubber" above

Tachometer – is your engine due for routine maintenance?  Has power output changed?  You won't know without a tachometer/hour meter.

T-Nut milling tool – installing T-Nuts will beef-up the propeller-hub mounting system.  It is Miniplane's response to the rumor-mills on the PPG blogs.

Threadlock – an important item in a pilot's toolbox

Throttle placement in the hand while launching a paramotor

Throttle support breakage – see "Metal fatigue" above

Throttle cable – cleaning, lubrication, important modifications, and cruise control info.  For kill switch issues, see "kill switch problems" above.

Throttle return spring replacement – improve throttle response, lessen hand fatigue with this modification/replacement.

Timing, checking the value – see "Ignition timing check" above

Timing the Top 80 – see "Ignition timing" above

Tools – Paramotor essential tool kit

Torque values

Troubleshooting the engine – see "Performance issues" above

Tune-up – see the WG carburetor page

Vapor lock – it is the most common fuel problem in paramotors due to the near universal location of the fuel tank far below the carburetor

Vibration – see "Propeller hub info, removal, & installation" above

Walbro WG carburetor – see "carburetor" above

Warming up – When the cylinder head temperature reaches 70ºC, the fuel/air mixture is 100% vaporized so the engine will not be fuel starved and potentially overheat.  Various moving parts of the engine must also be at the correct temperature to reduce wear and seal properly.

Water in fuel

Weight – 20.7 kg (45.5 lb) all up weight minus fuel

Wrist pin circlips – see "Piston wrist pin circlips" above

From Miniplane-USA

Parts – Miniplane-USA has excellent stock of everything and the best service.  This site (in French) has detailed diagrams and information on every part in the Top 80 engine so that you can order the parts you need accurately.  It is also handy when repairing the Top 80.  "Where does this part go?" WARNING: Some of the part diagrams have errors in parts placement so caution is advised.

From Miniplane Italy

Disassembly of the Top 80 – Part 1  Part 2  Somewhat detailed video on how to take apart the Top 80 properly.  It does not include disassembly of the motor itself (cylinder, head, reed valves, clutch, redrive).  If the motor needs additional disassembly, see the respective notes on this page.

Historical features of the Miniplane – from the 1990's

Official website for operation & maintenance – it is now in English and updated by Miniplane about every 10 to 15 years.  However, the English version of this site may not be online at times.  Go here for Miniplane's professional service information but, as often as not, you will receive the "HTTP Error 404.0 - Not Found" error.  The Southwest Airsports website would not exist if it were not for the incompetence and neglect of the web design people used by Miniplane IT.  To give them credit, they have the most bug free paramotor made but only because it has been around for decades.  Vittorazi is hot on their heals but they are still dogged by annoying bugs.

From Mark Kubisch

Service Notes – Redrive overhaul for older grease filled units (including lubricant replacement) & pull start cord replacement.  When reassembling the cases, use grey type RTV sealant.  Be sure to follow these instructions when applying RTV cement.  Mark's technique for removing the propeller hub will damage it.  Remove the hub with heat, as shown on this page.  Also, bearings will simply drop out of case halves if proper heat is used.  There is never any need to pry/pull on anything if the proper techniques and tools are used.

Pullers should never be used when working with aluminum.  However, they can be used to gently remove things that are snug but only tightened with the fingers.

When removing the main redrive gear, do not let anything metal (steel) come in contact with the case half.  Thin pieces of wood can be used to protect things.  The small pinion should easy slide off the shaft and does not need to be pulled.  Removing the bearings is easy.

From Alex Varv

De-carbonizing a two stroke engine – Alex Varv shows how to do it without removing the cylinder.  However, I do not recommend using any sealant between the cylinder and cylinder head.  I have never had a  head leak when the "O" ring is new and installed properly.