You need to understand the problem a bit more, first.
Engine components are buit to certain 'tolerances'. None are built EXACTLY to the design and they will vary AROUND the ideal shapes, measurements, etc..
Let's look at something simple. An engine with its inlet slightly larger, but still within the legal tolerances' may well be quicker than one that is slightly smaller but which is also, within legal tolerances. The same is true of exhaust port sizes too. In fact, almost every single component probably has a range of tolerances, some of which will make it quicker or slower.
By chance, you buy an engine which is a mixture of these 'good' and 'poor' components..... just like most other people do. Now..... if you could MACHINE the inlet port out to the PERFECT (but still dimensionally-legal) size, then your tuner could improve the perfomance of your engine up to the level of where EVERY component was a 'good' one, even though they were DELIVERED as a 'mixed bag' of good/poor.
In many classes of racing, that is what you'd expect from an engine that is described as 'fisched'. It often means that it's an engine that hase been MACHINED to be exactly in line with the 'fische' (i.e., the 'blueprint' from which the engine was built). However.......
You are NOT allowed to machine most components in a TKM or Rotax. Thus, you MAY not be able to buy what you may be THINKING you can buy. A Fisched Rotax will N*O*T have been re-machined to perfection.
However, there's another option.....
Buy 100 Rotaxes.... dismantle them ALL! Carefully measure every SINGLE component and select the parts to make a SINGLE engine from the best of all the components in that HUGE pile of spares. Rebuild the remaining and sell them as brand new....... (In reality, you find you can build 10 good motors, 89 tolerable motors and one B*A*L*L*I*S*T*I*C motor from your 100. You keep the 'ballistic', sell the 10 as 'selected' and the remained as 'standard'!)
The 11 (10 + 1) could ALSO be described as a 'fisched' motors. You have built one absolutely TO the 'fische' without needing to 'machine' a single component....
Finally, an engine can be described as 'fisched' if a tuner has ADJUSTED all the things he's ALLOWED to adjust (e.g., thickness of gaskets, etc.) or by selecting compnents which MATCH each other (e.g., where he selects an exhaust with a high-top to go with a barrel with a high-top so that gas-flow will be smooth at the join.
So...... be aware of quite how complex the use of the word 'fisched' can be..... it's not as simple as you might expect! I recommend NOT using that word but asking a seller what ACTUAL work was done rather than: 'is it fisched?'. The answer you get may NOT be the one to the question you THOUGHT you had asked!
Finally, have a guess QUITE how expensive that BALLISTIC engine would be........
Ian
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Rotax engine - fiched against unfiched by 'HarryH1997' (27 Sep 2010 @ 22:30)
