throttle and choke return springs

[Slyfox]

Larry,


As for the "choke", I use a locking t--handle cable from McFarland that works nicely. You can wrap 2 fingers around it and pull & rotate it very easily. The original custom ring pull cable works well also, but without a locking feature (which allows you to have your right hand free for the throttle, or whatever).

I need one of these, what part no. did you use and where did you get it?

[jrevens]

I need one of these, what part no. did you use and where did you get it?

Hi Steve,

They’re made by McFarlane. You can buy the dual cable for the Rotax and then the T- handle for it.

[Slyfox]

great thanks, went to there site and found what I needed. thanks

[Shadowrider]

I also removed the springs as I think they are a safety issue. Last thing I want is throttle going WOT especially at cruise having an engine runway past red line ending up in a pieces. I also installed the vernier throttle. They are my favorite. I use the twist feature all the time to adjust power and it is very accurate. Pricey, but quality built.

[Jerrytex]

Another vote for taking them off.

I Took them off my KF 4 and used the standard friction throttle. Worked/works fine. I plan on taking them off on my new build as well.

[jiott]

I am really curious about all the talk about vernier throttle cables. I have never personally ever found the need or want to adjust my engine speed to the very fine degree possible with a vernier type throttle. The standard friction screw knob gives me more than enough adjustability. Just for my own education, I would like to hear what phases of flight you guys feel the vernier is an advantage? This is an honest question; I am not trying to trash the use of a vernier because obviously a lot of folks seem to prefer it. Maybe I could improve my flying with a little education, especially from those who have tried both on the same airplane and prefer the vernier.

[Shadowrider]

I have flown both. 90% of the time I am twisting the throttle. Vernier is the best way to go. Only time I am pushing and pulling the throttle is takeoff and landing. Vernier is much more accurate at adjusting rpms and manifold pressure. John, on a NA engine its not as big of deal because throttle is not as sensitive. With a turbo, I wouldn't run anything different, especially with a fixed pitch prop. You would be all over the place. The mcfarlane is nice because you can push and pull the throttle quickly, without pushing a button, and then you can twist it to give it an accurate adjustments. Turbulence they are nice. Updraft I give it twist out, down draft 2 twist in. Once its smooth a twist back and its right at 5200rpms I also like them for starting up. Pull throttle out then two twist in and she starts up 2000rpm every-time.

[3kdscf]

I am really curious about all the talk about vernier throttle cables. I have never personally ever found the need or want to adjust my engine speed to the very fine degree possible with a vernier type throttle. The standard friction screw knob gives me more than enough adjustability. Just for my own education, I would like to hear what phases of flight you guys feel the vernier is an advantage? This is an honest question; I am not trying to trash the use of a vernier because obviously a lot of folks seem to prefer it. Maybe I could improve my flying with a little education, especially from those who have tried both on the same airplane and prefer the vernier.

I have the 912ULS in a Kitfox 6 with a series 7 firewall forward. The reason I am making the switch is that the factory provided throttle cable, even when clamped down as tight as I can turn it, slowly creeps up in RPM. It does this at cruise RPM but way more annoyingly at idle. Trying to do a pre takeoff checklist when you have to keep taming the engine to keep it from roaring can be pretty distracting. What I am really describing here probably has nothing at all to do with the throttle and everything to do with the really strong springs. I probably could have solved the problem with just springs but I decided that while I was at it, I would replace the throttle as well because I like the vernier idea. The big use for the vernier for me personally would be for cruise RPM. It often takes me several tries to get the RPM I want at cruise whereas with a vernier, it would just be a quick twist.

[avidflyer]

I have the veneer style throttle on my Kitfox 4 with 912. I really like it, I did install weaker springs as well. Usually I will grab the throttle ball with my first and second fingers, and when they pull, the button is pushed in when it pushes against your palm near the bottom of the fingers. It is very nice for larger throttle changes. For a small change in throttle setting, the twisting of the ball works very nice. I do have another friction lock throttle, but even though I'm a bit on the frugal side, I'll buy the veneer throttle for the next project. I would say though that weaker springs will go a long way to making what you have tolerable. Here is a short video of my first flight I did in the plane, and you can see how I held the throttle. Of course in cruise, I'm not usually holding the throttle, this was just up and around and down, and I don't use the twisting motion much. Please excuse the cheap chinese gopro camera copy. Sound out of sync, and picture quality not near as good as the real deal. JImChuk
Kitfox 4 first flights after rebuild panel view - YouTube

[3kdscf]

I also removed the springs as I think they are a safety issue. Last thing I want is throttle going WOT especially at cruise having an engine runway past red line ending up in a pieces. I also installed the vernier throttle. They are my favorite. I use the twist feature all the time to adjust power and it is very accurate. Pricey, but quality built.

First ,time for a TeamKitfox Forum appreciation moment. In the pre-internet days, getting information like that found on this thread was difficult and time consuming. Who knows how many lives easy access to this kind of information has saved. Enough gushing.

My Series 6 is a year old with 170 hours on it. I have the stock 912ULS throttle springs and agree, its really dangerous. Even with my hand on the throttle every second during base and final, it sometimes slips in my sweaty hand and goes to full throttle. Even when the throttle is locked tight at 2000rpm on the ground, it slowly creeps up in RPM.

I will look into the weaker 6822 springs used by the Vans RV-12 as well as the Vernier-Assist throttle. I know the strong springs insure the throttles stay synced but for me, the risk of a full power surprise at an inopportune time is more dangerous.

My plan is as follows:
1) try the vernier assist throttle with the stock strong springs, if that doesnt work ...
2) replace stock throttle springs with the weaker 6822 springs, if that doesnt work ...
3) take the springs off entirely and make sure cables are solidly supported entire length to minimize sync problems

Thanks everyone!