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Old 05-31-2014 | 12:07 AM
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Mr Cox
 
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From: Karlstad, SWEDEN
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A good fuel is very important. I would recommend that you buy commercial fuel at first and only make your own once you get the hang of it, and get to know your engine.

With experience you will know how to tune it, each engine will also have its own little quirks, but that's the charm of it all. In principle a cold engine needs a little higher compression ratio to start, so once it is running the compression should be lowered. This is usually about 1/4 to 1/2 turn, and that will be the final compression setting. Don't worry if it misses a little, it will usually not stop running.

Once up to operating temperature you can find the correct settings by going from rich towards a leaner setting. Turn the needle in a little, if the engine picks up speed you are on the right track. If it picks up speed and starts to miss, then increase compression setting a little too. You can find the highest rpm as a function of compression setting but this should then be lowered to stay on the lower side (in terms of compression) of that setting. Make your compression settings at full throttle, the low end might then miss a little but that is not any real problem.

Set the low end needle for a good throttle response, not too rich. The low end can be set so that it misses a little, this makes sure that the compression ration is not too high. When the throttle is advances you get a very quick response this way too. While if the compression is too high, or the low end is too rich, it will hesitate.

Last edited by Mr Cox; 05-31-2014 at 12:10 AM.