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Need throttle curve help on gasser

Old 08-19-2010, 09:31 PM
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nappy99
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Default Need throttle curve help on gasser

I have DLE 55, my first gasser. Noted the throttle (butterfly) is much different responce to glow (barrel) type carbs. Specfically, with my gasser, at 1/2 throttle, I get 6300 RPM, and WOT I get 6700RPM....not much diff from 1/2 to WOT. The linkage is smooth and linear, I think the issue is that a butterfly carb doesn't work same as glow type. So my question...do you set in a throttle curve to compnsate...? If yes...do you still make the carb go WOT or do you set the curve that its MAX RPM...even if MAX RPM is not WOT ?

Suggestions ?
Old 08-19-2010, 10:07 PM
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Andrew_S
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Default RE: Need throttle curve help on gasser

Sounds like the end points are off and the linkage set up too...I have a steering arm on my throttle..The pushrod is in the second hole closest to the carb and on the servo end, its on the very end one. The radio is 100 on the idle and 100 on the wot...
Old 08-19-2010, 10:36 PM
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Default RE: Need throttle curve help on gasser

If you can, set a curve

On one radio it didn't have a thottle curve so I put a bunch of expo in.
Old 08-20-2010, 02:39 AM
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DaddySam
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Default RE: Need throttle curve help on gasser

I use a curve on my DLE engines. I have the first five points or so set so that the first 3/4 of stick only moves the throttle about 30% then the last two points take it open to 100%.
Sam
Old 08-20-2010, 07:08 AM
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Default RE: Need throttle curve help on gasser

I slow the bottom end response on my 55' as well.
Old 08-20-2010, 07:53 AM
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ec121
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Default RE: Need throttle curve help on gasser

The first thing to do is lengthen the carb arm to match the servo arm so they move the same. The little short carb arms will really complicate setting up linkages. Then use the curve for the final setup. I tap the holes in the carb arm to 4-40 or just bolt a piece of fiberglas, etc. thru the hole in the arm. You can also offset the arm that way for better geometry.
Old 08-20-2010, 12:11 PM
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Default RE: Need throttle curve help on gasser

looks this way
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Old 08-23-2010, 12:42 PM
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nappy99
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Default RE: Need throttle curve help on gasser

that is quite the curve ...thanks !
Old 08-24-2010, 08:00 AM
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DMyer
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Default RE: Need throttle curve help on gasser

I don't have throttle curve programming available on my old 8 channel.... so used a mechanical curve... at idle - the thottle servo arm is almost pointed at the motor.... full thottle is about 90 degrees. Seems to work very well... but if anything... I could still use even less initial advance... someday I am going to have to upgrade my transmitter!
Old 08-24-2010, 09:11 AM
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RPool
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Default RE: Need throttle curve help on gasser

Does anyone know what size and thread the walbro throttle lever screw is?? I want to use the blue metal servo arm on top of the throttle arm of my walbro carb and secure the two together. However, the throttle lever screw is not long enough to pass through the servo arm AND the walbro throttle arm. I need a longer screw. The screw is part # 96-142 but I don't know what size it is. I looked on the website and left a voicemail. Does anyone know what size and thread the walbro throttle lever screw is??
Old 08-24-2010, 10:56 AM
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JoeAirPort
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Default RE: Need throttle curve help on gasser

It's not exactly 4-40 but 4-40 will thread in there safely. Use a tiny bit of blue lock tite. You don't want it coming out. I have done this on two engines and it works awesome. Use as long of a bolt as you can to get the most threads in there....but don't bottom it out and snap the bolt of course.
Old 08-24-2010, 10:59 AM
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RPool
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Default RE: Need throttle curve help on gasser

Thanks Joe. I actually just got a call back from Walbro rep. He said it was a 4-40 2A screw.

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