DA 50 w/ KS 86 canister non-linear throttle

[DATech]

Ahhhh.... It is measured down the centerline of the pipe.
Your header may actually be the right length, or close to it. Let us know what the "new" measurements are.

[shall36]

Here's a pic of the canister and header. When I measured using a string along the centerline of the pipe, it comes out a bit longer than 10".

[swheaton]

22x8 wood seems to be the best prop for a da 50.on a 10" header

[shall36]

Quick update for those interested...

I have about 4 gallons through the motor at this point. The spike is still there. My head temp at idle (following a full flight) is low: under 145*. I'm pretty sure this means I can lean out the low end, which may resolve the power spike issue. I'll probably work another gallon of fuel through before doing this (or is it "safe" to do it now?).

When I get the needles set to get my head temps up to 180 or so, I'll re-check things. If I still have the spike, I'll try a 22 x 8 prop. If I still have the spike, I'll try splicing in a short section of tube to the header.

[3ddd]

if you are way rich on the lowend it will cause a jump in rpm if you have the topend set correctly.at about 1/2 or 1/3 throttle it will transition from the lowend jet to the highend jet and if the topend is leaned for best run it will jump

[shall36]

I suspect as much. What's funny is that I did lean out the low end needle at one time (after about 2 gallons through the motor), but maybe I didn't tune it right. I probably need to richen up the high end needle a tad and then creep in on the low end needle?

[xtra330]

i would contact KS themselves and inquire on the length header required for that set up....I have had simlar problem on my 150 and KS cans...come to find out the header length recomended by DA is not what Mr. KS recommends....I have 11.5" header, KS recomends roughly a 8" to 8.75" header....just FYI...

Joe