I have a dual throttle setup on my 701 with a Rotax 912ULS This is the kit that zenith provides with two cables. There seems to be a lot of pressure pulling the two throttle arms on the carbs back to full. If I take my hand off the throttle it will advance the RPM greatly. I have to tighten the throttle lock down very hard to stop this action. Rotax says not to change the carb springs. I took the springs off to see if it was a cable issue , but no problem with the cables. I did reattach the springs. Can't take left hand off throttle to set flaps or adjust elevator trim. Is there a better cable system out there that I am not aware of. or should I change out the spring to lighter tension ones.

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Comment by Shay King on April 3, 2019 at 5:43am


There’s already quite a bit of discussion about this in the 701 forum.

A vernier throttle with friction lock is a good solution.

Be careful using weaker springs. You’ll find reference somewhere to Jon Crokes crash, he replaced his springs with weaker ones and during a go-around they weren’t strong enough to give him full power and he crashed.

Comment by Shawn Magin on April 1, 2019 at 1:28pm

I use the lighter springs offered by mcfarlane aviation...made a very noticeable difference.

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