For the Hyper 21 it is recommended that you use 16% - 25% nitro, that is what they come pre-shimed for.

Check that the carb is seated on properlyon the engine.

Before you start the thing up you need to set the carb up properly.

So wind in the MSN till it's just below flush.

Wind the LSN out a few turns.

Close the sliding barrel right up and adjust the Idle screw till there is a 1mm gap down the thraot.

Now wind in the LSN till you feel resistance (NO FURTHER) and then wind it back out 3.5 turns.

Next wind the HSN in till you feel resistance and then back out 3 turns.

******First start******

Squirt a few drops of After Run Oil (ARO) down the carb throat and in through the plug hole.

If in cold climates it is a good idea to warm the BLOCK of the engine up to over 100'F (#40'C) as this will help the engine to rotate more freely.

Fit the air filter.

Now turn the engine over (spin the crank) a few times to lubricate it.

Now fill the fuel tank and prime the engine by blocking the exhaust and turning the engine over till fuel spits from the plug hole (Caution should be taken to avoid fuel in the eye).

Fit the plug but leave it a turn loose.

Now place the (CHARGED UP) glow stick on the plug and yank the cord/bounce th car on the box. It may jam up but then you just need to prise the flywheel back to a free spining area.

It WILL run, you just need to persist in this bit.

Once runing tighten the plug up.

Allow it to run for 5 minutes at Idle and the shut it off. Allow it to cool for 5 minutes and the start it up again. This time it should just be a case of yanking the cord/ Bouncing on the box with the ignitor on.

You need to repeat this for 6 tanks to do the break in fully, it takes about 6 hours to do and will help the longevity of your engines life. Not breaking in a Hyper 21 engine correctly will cause the conrod to snap and possibly take out the piston too. DO NOT rev the engine over 1/2 throttle uring this stage.

******TUNING******

With the engine runing start to wind the LSN in by 1/8th increments till it accelerates without boging out. (It will still bog in the mid/high range).

With the LSN set start on the HSN, wind it in in 1/8th increments till it rips up the dirt without spiting oil. It should however still have a good plume of VISIBLE smoke. Without the smoke, again you WILL throw the rod.

Check the idle speed and ensure the brakes are not stoping the whels at Idle (this will induce a brakeing force on the engine and cause a perfectly tuned engine to stall unexpectadly and causing you to fiddle when you need not.

That's it done, nothing to it really but it seems that people just cant do it. So follow this guide and the H21 will serve you well.