Frequently Asked Questions

1. What fuel to use for MVVS glow engines?

We recommend to use quality fuel with castor oil in a ratio of 1: 4 (20 % oil). This ratio is also suitable for running-in. Do not use unproven synthetic oils!

2. What fuel to use for MVVS petrol engines?

We recommend to use 95-octan unleaded petrol with Mobil Racing 2T oil in a ratio of 1:40 (1:30 for running-in).

3. What fuel to use for MVVS petrol engines?

For glow engines 2 - 4.5 ccm: Novarossi C5S
For glow engines 6.5 - 35 ccm: Novarossi C6S
For petrol engines: NGK CM-6

4. Can nitro be used in MVVS glow engines?

Nitromethane can be used up to 5 % without adjustment, above 5 % (5 - 15 %) the compression ratio must be adjusted by inserting another washer under the cylinder head. When the engine is running at max. speed, after disconnecting the glow plug, the engine speed must not decrease or increase. (If the speed drops, the compression ratio is too low, if it increases it is high.)

5. Why does the piston rub at the top dead center?

The design of the ABC engines is characterized in that the piston has a larger diameter than the cylinder liner at the top dead center. Therefore, especially the new engine rubs at the top dead center. This is not a fault and the piston will never seize for this reason (assuming the use of quality fuel with castor oil). The engine must be turned quickly so that the piston slides over the oil film and does not rupture.

6. Why does the engine have a large clearance on the crank and connecting rod pin?

The plain bearing needs a clearance (about 0.04 mm) to form a lubricating film, otherwise it would seize. These clearances add up to the clearance of the ball bearings and, through the crank mechanism, manifest themselves as a considerable angular deflection of the crankshaft.

7. The crankshaft is free in the bearing, it has an axial play

The crankshaft must be slidably mounted, tightening the propeller to define the axial play.

8. Is it possible to turn the fuel supply (nozzle) on the carburettor?

No, it is not possible to change the position of the nozzle intake, which is important for the proper function of the carburetor.

9. How to treat the glow engine after operation?

After operation, especially if the engine will not be operated for a long time, the engine must be flushed with kerosene and then preserved with preservative oil (eg: Konkor). This is especially important when using nitromethane fuel. Residual castor oil left in the engine can corrode bearings and crankshafts.

10. How to recognize the correctly set idle speed?

The idle speed is set correctly if, after closing the slide from full opening to idle speed, the engine speed drops, after 1 - 2 sec. they increase slightly and then remain constant.

11. The engine has a heavily carbonized piston and exhaust manifold and heats up.

The cause is usually the engine running at very low speeds, which do not correspond to the exhaust used. A lighter propeller must be used.

12. The engine is vibrating a lot

The cause may be a poorly balanced propeller or an incorrectly set carburetor (too rich mixture). The new engine also has greater vibrations due to the tight cut, but these are reduced after running-in.

13. The motor works in a horizontal position, it goes out when lifted to a vertical position

This may be due to the use of a propeller that is too heavy, the engine speed is low and the carburetor cannot operate properly. It is also necessary to maintain the correct position of the tank in relation to the engine (fuel level at the level of the carburettor nozzle, tank as close to the engine as possible).

14. Is it possible to attach a flue gas hose to the exhaust of the glow engine?

This hose can only be used with tuned shock absorbers (black), when used with standard shock absorbers there is a risk of the engine overheating, reduced performance and impaired carburetor function.

15. The petrol engine cannot be started, it has low compression

The engine must be sent for repair. The cause is usually a baked piston ring in the piston groove. It is necessary to use the recommended oil (Mobil Racing 2T) and ensure sufficient engine cooling in the model.

16. Can a new ignition be used on an older engine?

It is possible, but it is always necessary to replace the propeller carrier, as the position of the control magnets differs.

17. The petrol engine starts, runs normally, but it is no longer possible to start after stopping

This can be caused by the ignition safety fuse, which trips when the engine is at a standstill for more than 1.5 minutes. The ignition must be switched off and on again.