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Weird "spot" in AFR target map

Understanding AFR

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Hi,this a question about a weird "SPOT" that i noticed in all afr maps that i saw in the SEADOO watercraft,engine is a 900 ROTAX ACE,son i cant explain why do they made the map like this.

Picture attached.

regards and thanks

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Possibly a place that has a tendency to knock, or a place where the engine spends a long of time, and needs a bit extra fuel to keep it cool. It could just be a place that is very effecient in terms if intake / exhaust so that's what the engine wants!

If you can get that thing on a tank dyno, I'm sure you will be able to discover the true answer.

Hi,thanks for the input.

well ,a knock it could be,other options posted i don't think,in watercraft, the range where engine is working is wery extended because of wavejump,and throtle is almost at 80-100% open.In tuned files this spot disapears.

Geting the engine on a dyno is dificult, there are a very limited dynos in the world for this.


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