paragliding training center
It is a good idea to check Polini's website to get the latest (or additional) information. If you find errors here or things that will help other pilots, please contact us. We try to be as accurate as possible but the marketing departments make this task difficult and sometimes impossible. Please note that the factory manuals sometimes are missing critical information for the repair and maintenance of these engines. We do our best to fill in these gaps.
The Thor models share a common design and many parts. If you cannot find the info you need below or on the individual Thor model pages, check the Top 80 section for a wealth of info that is common to all Italian paramotors.
General assembly instructions - It is CRITICAL when assembling the Thor engines that the manifold mounting nuts be properly torqued with blue threadlock if you do not want any leaks.
Airbox support problems – The airbox tends to slip crossways onto the carburetor and leak after the engine is run for some hours. Here's the fix.
Assembly video – This is for the Thor 130, other models similar.
Bearing condition – What condition are the bearings in my engine? Which one is the most likely to fail first?
Carburetor* – The Thor 100 and 130 use the WG-8 The Thor 190 and 200 use the WB-37. If your
engine is not purring like a kitten in the
mid-range, you need to perform the midrange modification on your carburetor. The Thor 250 has a custom Polini carburetor (we do not stock
this one). It is more like the Bing which has a fuel bowl.
Case assembly – see "Bearing replacement and case assembly" above
Choke control – This is needed for safety and convenience.
Clutch – Information and servicing procedures.
Clutch Oil – Here is a list of the oils that can be safely used in the Thor redrive.
Coil secondary wire replacement – This is one of the most common points of failure in ignition systems.
Cylinder head gasket set and exhaust flange gasket* – contact us to order
Electrical troubleshooting – How to check the electrical system
Exhaust flange springs* – Use paraglider line to stretch the springs for
replacement/removal. Do not use Vise-Grips or pliers to stretch
the springs because this will nick the tempered surface of the spring and weaken it. Here is a video on how to properly do it. A defective
exhaust flange gasket cannot be fixed with RTV – replace the gasket. Use PG line (best) or aircraft wire to secure the springs if they break.
Exhaust system installation – 1. Install springs
first per above. 2. Install the buttonhead screw underneath carburetor first THEN 3. Install the
buttonhead screw underneath the springs. Use blue threadlock on screws and tighten 3-4 Nm (just snug, let the threadlock do its job).
Flash starter* – This starter has some major problems. Here are various solutions, including adapting the Miniplane Top 80 system to the Thor.
Flash starter Installation Manual – Here is the "how to" for installing the modified Flash starter insert into the original starter.
Frame cracks – see "Metal fatigue" below
Fuel system quick test – See the "Quick fuel system test" in section A of the link
Fuel system test – A more thorough test of the fuel system.
Ignition coil – the black wire goes to ground, the blue wire goes to the kill switch
Ignition timing check – This method will give the precise timing value that 100%
mechanical methods are unable to do. The Thor engines have
a fixed ignition timing contrary to the the Minari and Top 80 paramotors.
Kill Switch Problems – A low bidder made the wire used in the kill switch circuit.
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.
Mounts, rubber* – Here is a way to quickly check them. If you replace them with the heavy duty Viking mounts, do not make the mistake noted here.
Overhaul – see "Rebuilding 2 cycle engines" below
Performance Issues, general – This is what to do if the engine will not start or, for example, dies at full throttle
Performance tuning – Most paramotors run poorly in the midrange, the range that we spend most of our time flying in.
Pulleys – see "Starter pulleys" below
Rebuilding 2 cycle engines – When is it time? This general and helpful article
from Utah Motor Trails can help you decide and gives the basics on how
to do it. The upper connecting rod bearing in a well-taken care of engine will likely be the first part to fail. Here are some good tips from MCB
Performance on rebuilding two-stroke engines. Splitting open the engine case is a very technical job and requires special tools that will not
destroy the case halves. Go to this page for information on how to remove and re-install bearings and the correct way to seal the case halves.
Spark plug installation – this is the "how to". For type of spark plug see 'SPECIFICATIONS" below
Springs, exhaust – see "Exhaust springs" above
Starter – see "Flash Starter" above
Starter pulleys – The OEM Viadana pulleys will quickly wear out and fail. Here is the solution...
Starter Replacement Cord – The strongest and longest lasting you can install on your engine.
Starting – Start your engine the first pull, every time.
Stress cracking of engine components – see "Mounts, rubber" above
Throttle cable – Cleaning, lubrication, modifications, and cruise control info.
Torque Values – Check the specific Thor manuals on this website for most torque values. If you cannot find the correct value, check the the Top 80 specification page which has a thorough torque section. Hit "page down" twice to see it.