real power for your model airplane, PPG, Ull and many more applications

My engine is not accelerating properly and is burbling when I put full throttle, what should I do?

There are a few things you can try to troubleshoot the issue:

  1. Check the air filter: A dirty or clogged air filter can restrict the airflow to the engine and cause it to run poorly. Make sure the air filter is clean and free from debris.

  2. Check the fuel mixture: Make sure the fuel mixture is correct and well mixed. A mixture that is too lean or too rich can cause the engine to run poorly.

  3. Check the spark plug: Make sure the spark plug is clean and in good condition. A fouled or worn spark plug can cause the engine to misfire and run poorly.

  4. Check the carburetor: The carburetor is responsible for delivering the correct fuel mixture to the engine. Make sure the carburetor is clean and properly adjusted.

  5. Check for air leaks: Air leaks can cause the engine to run lean and cause poor performance. Check all the connections between the carburetor and the engine for air leaks.

My engine is rattling when running.

Here are some steps you can take to troubleshoot the issue:

  1. Check for loose bolts: Make sure all the bolts and screws on the engine are tightened properly. A loose bolt or screw can cause rattling.

  2. Check the propeller: The propeller could be damaged or unbalanced, which can cause vibration and rattling. Check the propeller for any cracks, chips, or other signs of damage. If it is damaged, replace it. Also, check the balance of the propeller, and balance it if necessary.

  3. Check the bearings: Worn or damaged bearings can cause rattling. Check the bearings for any signs of wear or damage. If they are worn or damaged, replace them.

  4. Check the fuel: Make sure the fuel mixture is correct and that the fuel is fresh. Old or stale fuel can cause engine problems.

  5. Check the spark plug: A faulty or improperly installed spark plug can cause rattling. Check the spark plug for any signs of wear or damage, and make sure it is installed correctly.

How should I setup carburetor properly. 

Properly tuning a diaphragm carburetor for maximum power and good transition requires a careful and systematic approach. Here are the steps to follow (Always be very careful and pay attantion to propeller turning at high speed, it may cause serious injury or death) :

  1. Start by adjusting the low-speed needle (L-needle) to get the idle speed set correctly. Turn the L-needle clockwise until the engine slows down, then turn it counterclockwise until it speeds up. Fine-tune the L-needle until you get a smooth idle.

  2. Next, adjust the high-speed needle (H-needle) to achieve maximum RPM. Start by running the engine at full throttle for a few seconds, and then quickly close the throttle to 1/4. The engine should slow down and then speed back up to a smooth idle. If it stalls, the H-needle is set too lean. If it bogs down and takes a long time to recover, the H-needle is set too rich.

  3. Adjust the H-needle by turning it clockwise to make the mixture leaner or counterclockwise to make it richer. Fine-tune the H-needle until you achieve maximum RPM at full throttle without overheating the engine.

  4. Check the transition from idle to full throttle. If the engine bogs down or hesitates, adjust the L-needle slightly richer. If the engine races and then slows down, adjust the L-needle slightly leaner.

  5. Once you have achieved a good transition, fine-tune the H-needle for maximum RPM again to ensure that the adjustments you made for the transition did not affect the overall performance of the engine.

  6. Repeat these steps as needed until you achieve the desired performance.

Remember, tuning a diaphragm carburetor requires patience and a systematic approach. Do not make large adjustments to the needles at once, and always allow the engine to warm up before making adjustments.

What fuel mixture should I use? 

In general, most ZDZ engines run best on a fuel mixture ratio of around 32:1 to 40:1 (gasoline to oil). For example, for a 5-liter fuel tank, you would add between 125 and 160 ml of two-stroke oil to the gasoline.

When selecting an oil, it's important to choose a high-quality synthetic two-stroke oil that is specifically designed for air-cooled engines. ZDZ recommends using a high-performance synthetic oil that is specifically formulated for use in two-stroke engines, such as Motul 800 2T or Red Line Two-Stroke Racing Oil. In general you can use any oil made acording to JASO FD standard. 

As for the octane number, ZDZ engines are designed to run on high-octane gasoline with a rating of at least 91 RON (Research Octane Number) or 87 AKI (Anti-Knock Index). Using a lower octane fuel can cause engine knock and other performance issues, so it's important to use the recommended octane rating for your engine.


Pilots, planes and installations

Wolfgang Krahofer (Austria) ZDZ 180B2RV-J


16.6.2022 New service logistic announced. See more on http://www.facebook.com/zdzrc

5.1.2022 Magic year of the 30th ANNIVERSARY of the ZDZ engines on the market just started. See more here:

22.05.2020: New ZDZ 210R2-J CHAMPION released and added to our website.

See more here.

27.11.2019: New distributors in Finland and United Arab Emirates

More details on our facebook or in contacts

28.5.2019: ZDZ 500B4-JSR added to our website 

The biggest engine of ZDZ line now optionally equipped by belt reduction gear. Check this beast in QUAD section. 

13.2.2019: New prices set for engines in eshop.

The most of bigger engines are now cheaper. Go and check, register your engine in our form (see in the center of page) and get even lower price for your next purchase.  

13.1.2017: Second service and support center in Czech Republic/ druhé středisko  servisu a podpory pro ČR

RC modely-PH
Václavské nám. 254
Kutná Hora
284 01
tel 777152293 email:


26.09.2015: New videos added 


07.02.2015: Pages update 

Dear Friends,
since yesterday 7PM till today 11Am, we have problems with email servers forwarding because of changing and adding domain names into our systems. If you sent anything within that period and received returning message, please forward your message once again.
Thank you and sorry for inconveniece.

04.02.2015: Pages update 

New distributor for BENELUX and UAE, see contacts-distributors for details. 

01.02.2015: Pages update 

New items added to the shop. especially spare parts were significantly updated and filled. And more to come........

31.01.2015: Pages update 

ZDZ 90RV-J,  ZDZ 112B2RV-Jch, ZDZ 180B2RV-Jch, ZDZ 250B2RV-J and ZDZ 224B4-J pages  update with new animation and downloadable 3D model where you can measure anything from installation dimms.

Also new items were added into spare parts section in eshop. 

08.01.2015: E-shop filled with all engines. 

Since today for those countries where we do not have oficiaal dirstributor our customers can order engines directly from our eshop. Soon we will add parts and accessories to it as well. 

20.12.2014: ZDZ 112B2RV-J Champion

Already well known for its smooth run and awesome power to weight ratio two stroke 112ccm opposed twincylinder model gas engine with procesor controlled ignition. Now fully CNC made crankcase and backplate out of 7075 aluminium alloy so very clean design bringing better quality as well. Weight increased compared to former 112B2RV-J is only 50 grams. 

ZDZ 112B2RV-J Champion

17.12.2014: Technical support in France

We have agreed with one of our most experienced pilots and friend Nicolas Gastaldi, that he will kindly support users in France. In case you have a problem with setup or tuning the engine or need advice, please contact Nico on email nicogasta@hotmail.com. Of course you can contact us directly as well, but we speak only english unfortunatelly. Thank you Nico for your help and very good representation of ZDZ engines at all. 

ZDZ 180B2RV-J  Champion finally available.

This the most powerfull engine in its class now comes with much nicer design with fully CNC machined crankcase and backplate and some other modifications like forged steel con rods to bring super long lasting power and durability.