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ORIGINAL: craigteffe

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ORIGINAL: krproton

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ORIGINAL: craigteffe

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ORIGINAL: krproton

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ORIGINAL: maukaonyx

Guys,

I have a DL-50 for my first gasser, a 30% Extra 330L. Still in the assembly stage. THis is a long thread and I tried looking awhile and also tried the Search feature, but did not find an answer to my question...what size tubing (inside diameter) do you use on this engine? Funny how the instructions don't even recommend a size. I know it should be Tygon, but should it be 3/32", 1/8", or 5/32" inside diameter? I see Dubro offers those three sizes of Tygon. Thank you. Jon

I use the DuBro No. 506 30' roll Tygon Large. Don't know which one that equates to in the 3' rolls, but I think it measures 1/8" (I inserted a piece of 1/8" brass tubing into the fuel tubing and it goes in with a bit of a "squeak," so I'd say it must be 1/8" I.D.).

I use the medium tygon and the reason why is the fuel line will swell a bit in the tank, i know this because i had a fuel line come off in flight. I also use the brass barbs solidered on the brass feed line in the tank

Barbs alone may not be enough. You should also use some kind of clamp around the line behind the barblike a small nylon zip-tie. I prefer safety wireespecially on the line that goes to the carbboth inside and outside the tank.

Yes this is how i also rig my tanks, stainless steel safety wire on the inside of the tank before and after the solider on barb and zip ties on the brass tubes outside the tank. i dont attach it to the carb with anything just slide it over the barbed fitting never had a problem there.

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ORIGINAL: Bob Pastorello

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ORIGINAL: krproton

Guys,

when I advance the throttle after extended down lines (when the throttle was at idle) the engine hesitates and sounds like it's going to quit before it "spools up" again. It always sounds like it's going to quit, but never has - just kinda unnerving.

My needles are set so at full-throttle it runs perfectly and at half-throttle or a little below it burbbles/four-strokes (if that has anything to do with it which I don't think it does).

Any suggestions?

Tim, nearly always a "throttle up" hesitation is too lean a low needle. It is easy to miss the sweet spot, since the low end affects the high, you can be tweaking away and get the high "perfect", but the low is lean.
My "test" is to leave a fully-warmed up engine at it's sitting-still idle....if it gradually speeds up, the low end is lean, if it slows, it's rich. Very much like glow motors.

I try for a solid idle without variation, even if left at idle for 30 seconds or more, then advance (dump) throttle to full immediately. If your low end isn't right, you'll see it RIGHT there.

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ORIGINAL: maddog 71

Hey krproton I see ur from Champaign are u going to be at the IMAA event on 8/23/08 or 8/24/08 there in Champaign
Maddog

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ORIGINAL: krproton

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ORIGINAL: Bob Pastorello

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ORIGINAL: krproton

Guys,

when I advance the throttle after extended down lines (when the throttle was at idle) the engine hesitates and sounds like it's going to quit before it "spools up" again. It always sounds like it's going to quit, but never has - just kinda unnerving.

My needles are set so at full-throttle it runs perfectly and at half-throttle or a little below it burbbles/four-strokes (if that has anything to do with it which I don't think it does).

Any suggestions?

Tim, nearly always a "throttle up" hesitation is too lean a low needle. It is easy to miss the sweet spot, since the low end affects the high, you can be tweaking away and get the high "perfect", but the low is lean.
My "test" is to leave a fully-warmed up engine at it's sitting-still idle....if it gradually speeds up, the low end is lean, if it slows, it's rich. Very much like glow motors.

I try for a solid idle without variation, even if left at idle for 30 seconds or more, then advance (dump) throttle to full immediately. If your low end isn't right, you'll see it RIGHT there.

Thanks Bob.

I got in three more flights tonight and I think I have the hesitation thing cured;

First though, I must confess, I also switched propellers. Yesterday, when I was experiencing the hesitation problem, I nicked my brand new carbon Mejzlik prop on my final landing (crap!!!).

So I had to go back to my Zinger wood Pro (also a 22 x 8 - same as the Mej).

So, after I mounted my Zinger, I tweaked the low end by richening it ever so slightly - I also richened the high end just a hair as well. On the ground, the idle RPM seemed constant.

In the air, there was no hesitation at all - it seemed to be totally all gone.

One other thing, yesterday it was pretty hot and humid, but today it is not quite so hot and less humid.

Well, the problem seems to be all gone. Tomorrow I am going to fly my new propeller - Xoar 22 x 8 laminated.

I'll keep you posted.

Thanks again!!!

Tim

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ORIGINAL: skillet92

Guys all i have to say is WOW . I ran the engine for an hour tonight at 2500 going to full throttle at 15 minute intervals. The engine started as soon as i figured how to get fuel to the carb and idled after finding out the trim was to low. it hit 7000 by 30 and by the time the hour was up it was at 7150. I do have one quetion. I have two reciever switchs but tonight only had one 2000 hydramax battery installed. at the end of one hour that battery was drained. this is not what i expected. i have hitec 985s coreless( my first coreless servos) do they drain more power or was the vibrations causing that much drain on the servos. Let me say that still have the throttle spring hooked up. i just don't believe that it would draw that much juice.