<div style="margin: 0cm 0cm 10pt">No experience with 175CDI yet, however, the 170CDI I have has performed very well this season. I found that a low oil content worked better for me, although the engine runs within the specification. Have not yet gone below 10% oil though.</div><div style="margin: 0cm 0cm 10pt">One thing to watch out for is that the engine gets proper cooling, installing foam to decrease the cross-section area (cooling air) made a difference.Next season I will also cover the header cut-out, so no cooling air escapes.The importance of cooling is mentioned in the YS user manual as well.</div><div style="margin: 0cm 0cm 10pt">The only weak point on the engine (170CDI) now is the plug cap, my personal opinion.The cap itself wears over time where there is metal to metal contact with the plug.Hence the plug cap gets loose after some flights (50-100 each 16mn in my case) and lead to occasional misfiring.I see the benefit of making the electrode pointed, but my opinion is that a loose plug cap wear is the root causeto misfiring.</div><div style="margin: 0cm 0cm 10pt">Another improvement should be to redesign the ignition box so it can be powered by 2s LiPo/LiIon unregulated.Also telemetry output of the RPM!</div><div style="margin: 0cm 0cm 10pt">Other than that a great engine, and if you are aiming to become a World Champion one day, you better stick to YS

Arnstein</div>