Thanks Texas!

I'll get on it next week and report. The engine only has a few tanks of fuel through it so hopefully the reed(s) are intact.

This is all making sense now as it seemed as I was chasing the needles around the 'surging' would subside and I thought I was onto something, only for the loping to return. It would appear that the reed is almost in correct position but not fully, just on the edge of working properly? Hmmmmm.

The mod will be easy enough, but, honestly, if the good folk here are on to a fix like this you'd think DLE would get proactive. Wishful thinking.

My third gasser project already on the table is another Hangar 9 plane (Hellcat). This one with a Zenoah G20.

My Mintor M33 has and this DLE will, certainly get sorted out. My loyalty to further projects will go to the engine that proves itself out of the box. All this barnyard-retro-bandaid-engineering is ridiculous. From what I've gathered from reading here and from what I've experienced thus far, the Zenoah will more than likely be that engine.

As far as I'm concerned Mintor and DLE have shot themselves in the foot.

Thanks again!

Originally Posted by FoamieAirfarce

Thanks Texas!

I'll get on it next week and report. The engine only has a few tanks of fuel through it so hopefully the reed(s) are intact.

This is all making sense now as it seemed as I was chasing the needles around the 'surging' would subside and I thought I was onto something, only for the loping to return. It would appear that the reed is almost in correct position but not fully, just on the edge of working properly? Hmmmmm.

The mod will be easy enough, but, honestly, if the good folk here are on to a fix like this you'd think DLE would get proactive. Wishful thinking.

My third gasser project already on the table is another Hangar 9 plane (Hellcat). This one with a Zenoah G20.

My Mintor M33 has and this DLE will, certainly get sorted out. My loyalty to further projects will go to the engine that proves itself out of the box. All this barnyard-retro-bandaid-engineering is ridiculous. From what I've gathered from reading here and from what I've experienced thus far, the Zenoah will more than likely be that engine.

As far as I'm concerned Mintor and DLE have shot themselves in the foot.

Thanks again!

That Zenoah should run out of the box for ya, best durn engines ever made, albeit a bit heavy for todays 3D stuff. But lots of warbird guys and racers fly them, Antique or Unmanned will most likely agree!

If you still have the stock spark plug in there, I would start by replacing it with a CM-6. Try opening up the plug gap to .025". That move by itself can really help a "miss" like you're describing up over 1/3 throttle.

You're also not loading the engine enough with your prop selection. That's not helping your cause a bit. KNOWN good props are 16x8 and 17x6. That should get you down into the 8400-8500 range, maybe a little lower.

Last, I'd suggest you re-tune again, and leave both adjustments just a little rich, especially with a newer engine. As you build time with it the engine will start to settle down a little, you'll get a little confidence with it, and a couple "tweaks" here and there on the tuning later on will have you grinning like most of the rest of us running this engine.... -Al

Originally Posted by AHicks

If you still have the stock spark plug in there, I would start by replacing it with a CM-6. Try opening up the plug gap to .025". That move by itself can really help a "miss" like you're describing up over 1/3 throttle.

You're also not loading the engine enough with your prop selection. That's not helping your cause a bit. KNOWN good props are 16x8 and 17x6. That should get you down into the 8400-8500 range, maybe a little lower.

Last, I'd suggest you re-tune again, and leave both adjustments just a little rich, especially with a newer engine. As you build time with it the engine will start to settle down a little, you'll get a little confidence with it, and a couple "tweaks" here and there on the tuning later on will have you grinning like most of the rest of us running this engine.... -Al

Thanks Al, yup, am running an NGK CM-6 and I did open the gap a bit, but had no gauge at the field, so I just put some slight pressure on the ground electrode gap with a pen knife, who knows, perhaps I didn't open it at all. So I just took my lazy azz out to the garage and got my gap tool and opened up a new NGK CM-6 out of the box. I had read somewhere on FG that an X-acto #11 blade width was, what? .016-.018 and a reasonable reference gap from which to start? Well out of the box and with a fresh blade the gap was considerably smaller than a #11 blade. The plug currently in the plane was 'out-of-box' gap unadjusted. I opened the new plug to .025 and I'll try that in the morning.

Will definitely swap out the prop for more pitch too. Kinda a small plane, and being a war plane wheel landings and long scale 'up-on-main-wheel' TO ground rolls will be the norm so more diameter wouldn't suit our grass field much.

I heard too, more than once out at the field, that it was OK to tune needles out-of-the-box but not to expect much until after a good break-in period. "Don't go chasing needles looking for 'perfect' because you will drive yourself nuts" was the sentiment. If it runs reliably then run it. I will and will consider the Reed Block Mod next...............

Thanks for the tips!

Originally Posted by vmceachern

That Zenoah should run out of the box for ya, best durn engines ever made, albeit a bit heavy for todays 3D stuff. But lots of warbird guys and racers fly them, Antique or Unmanned will most likely agree!

That would suit me just fine! Thanks again Texas.......................

Lots of good info here. The DLE-20 in my Pulse will be getting a Bowman ring and the reed block fix over the winter.

Originally Posted by grosbeak

Lots of good info here. The DLE-20 in my Pulse will be getting a Bowman ring and the reed block fix over the winter.

Are you experiencing any of the same symptoms as I am 'grosbeak' ? Just curious about 'trends' in motor makes......

I had the same issue with my DLE 20. It also had the aforementioned "miss" or burble about 1/2 to 2/3 up in the throttle range. running the engine and adjusting as it breaks in was the biggest factor in curing these issues. ive got about 3 gallons through it. the miss is almost completely gone now, and I can get a very low but reliable idle. I found also that once the engine is broken in you can get it to idle at a surprisingly low RPM. once you get it to idle down to ~1600 youre far enough away from that "bump" in the timing curve that it doesnt seem to be an issue. it also does like to be a little rich on the LS needle. that helps the engine slow down a bit when you close the throttle.

I flew today with the plug gapped to .025 and a 16X8 prop. The engine rpm peaked @ around 8100 and I flew the plane. The miss was all but gone and the engine ran well, but then................

..........I thought I should be getting a little more rpm, into the mid 8000's, so I retuned the needles. I tuned the high end and hit about 8300. The transition was darned decent so I left the low needle alone. The engine sounded great on the stand but the 'miss' was back in flight.

I reviewed some of the threads here and I realize I did a half azzed job of tuning. I didn't realize until today how much of the power band the low end needle commands..........from idle all the way up to mid range, where my miss and 'burble' are the worst. At full throttle = no miss.

I now realize my mistake (thanks to Ralph 'Antique') Just because the transition was good doesn't mean the low end needle was set correctly. I need to set the high, lean the low until it DOESN'T transition at all, THEN richen up the low just until the point that it will transition and reset the high once again. Done. I would imagine despite good transition I'm still too rich on the bottom?

I'll do that tomorrow and see where I get. If it still misses, I'll just fly the bugger for two more gallons (I'm only about one gallon deep) see if things improve like Joe's and think about the reed block.

I'm pretty ignorant about gassers I'll admit, and I do realize that the engines are geographically altitude sensitive and are therefore shipped at the 'ball park' factory needle settings, but I'm at a loss as to why my DLE needs tweaking out of the box and my Echo weed whacker doesn't? I mean those mixture fittings on that Echo? You CAN'T adjust those fuggers with any tool I have in my box, the thang just runs outa the box son!

Originally Posted by FoamieAirfarce

I flew today with the plug gapped to .025 and a 16X8 prop. The engine rpm peaked @ around 8100 and I flew the plane. The miss was all but gone and the engine ran well, but then................

..........I thought I should be getting a little more rpm, into the mid 8000's, so I retuned the needles. I tuned the high end and hit about 8300. The transition was darned decent so I left the low needle alone. The engine sounded great on the stand but the 'miss' was back in flight.

I reviewed some of the threads here and I realize I did a half azzed job of tuning. I didn't realize until today how much of the power band the low end needle commands..........from idle all the way up to mid range, where my miss and 'burble' are the worst. At full throttle = no miss.

I now realize my mistake (thanks to Ralph 'Antique') Just because the transition was good doesn't mean the low end needle was set correctly. I need to set the high, lean the low until it DOESN'T transition at all, THEN richen up the low just until the point that it will transition and reset the high once again. Done. I would imagine despite good transition I'm still too rich on the bottom?

yes. but remember my adjustment, even though "rich on the low end" is only slightly so, and much more lean than it was when I was first breaking in the engine. as the ring seats and the seal becomes better the engine will need to be leaned out slightly.

I'll do that tomorrow and see where I get. If it still misses, I'll just fly the bugger for two more gallons (I'm only about one gallon deep) see if things improve like Joe's and think about the reed block.

I would do the reed block mod, but if the engine runs satisfactorily dont mess with it until its broken in and stabilized. the last thing you want is to be changing things while youre still trying to figure out whats "wrong." Keep in mind that there are thousands (millions?) of these engines running every day without the 'reed block mod' ever being done. so the odds that your engine needs it are very low. that doesnt mean it wont benefit from it later once youre more familiar with working on them.

that being said attempting the reed block mod when youre not really familiar with how gassers work could be a recipe for disaster. it is easy to do, but its also easy to do wrong which will make your engine worse or not run at all.

I'm pretty ignorant about gassers I'll admit, and I do realize that the engines are geographically altitude sensitive and are therefore shipped at the 'ball park' factory needle settings, but I'm at a loss as to why my DLE needs tweaking out of the box and my Echo weed whacker doesn't? I mean those mixture fittings on that Echo? You CAN'T adjust those fuggers with any tool I have in my box, the thang just runs outa the box son!

your weed whacker is set to run at a much more restricted throttle range than your dle. its also relatively "dumbed down" with a smaller carb and more forgiving timing and porting that lend themselves for ease of use and easy starting "out of the box" convenience. think about how frustrating it would be if you had to tweak your weed eater out of the box just to get it to run reliably. not many of them would be sold as most people would find it a frustrating endeavor.. so be thankful that you don't have to adjust it.

the flip side of that is if you had our airplane engines set up like weed eaters, adjusted at the factory and locked in, forgiving porting, etc.. then they would most likely be very boring engines indeed. they wouldnt be very well suited to the wide throttle range we require nor would they have the power to weight ratio that we enjoy or the power available to the prop that we need. you may cite the "weed whacker conversions" out there as evidence that they are just as powerful, but keep in mind still that those engines are modified, sometimes heavily. with new, larger bore carbs and more. And most of the time they STILL dont reach the level of performance that an engine that is designed for our use reaches out of the box.

Thanks for the reply Joe, really appreciate it.............

Well, I tuned the engine today properly (thank you 'Antique') and it's good enough and reliable enough to plod on through the 'break-in'..............the low end needle certainly was 'rich' despite delivering a good transition previously. When I came back down from the lean side and found a good low needle transition setting I had to adjust the throttle servo end point to get the idle back down to something reasonable. I was that far off and yet the transition was good. Perhaps it's because the engine isn't close to being broken in

I'm getting about 8150 rpm on the high side, seems low but will probably improve with break-in, a very good crisp transition but the engine still revs (surges) off of idle by a 50-100 rpm only to fall back to about a 1600 rpm idle. No real rhyme or reason to it Not sure what's going on there, either I'm dancing on the thin line of the EI timing 'step' referred to previously in this thread or it's the reed..........not a deal/flight breaker.........once in the air the engine is reliable. And strong as all get out. I'm glad I have some pylon racer experience or this model would be darned intimidating!

Very odd tho' not a hint of a 'miss' on the flight stand but it will miss in the air, but not as bad as before. Dunno, maybe something to do with 'load'? Just gonna fly a few more gallons through it and re-evaluate then...............thanks for all the help............

Doug

Originally Posted by FoamieAirfarce

Thanks for the reply Joe, really appreciate it.............

Well, I tuned the engine today properly (thank you 'Antique') and it's good enough and reliable enough to plod on through the 'break-in'..............the low end needle certainly was 'rich' despite delivering a good transition previously. When I came back down from the lean side and found a good low needle transition setting I had to adjust the throttle servo end point to get the idle back down to something reasonable. I was that far off and yet the transition was good. Perhaps it's because the engine isn't close to being broken in

I'm getting about 8150 rpm on the high side, seems low but will probably improve with break-in, a very good crisp transition but the engine still revs (surges) off of idle by a 50-100 rpm only to fall back to about a 1600 rpm idle. No real rhyme or reason to it Not sure what's going on there, either I'm dancing on the thin line of the EI timing 'step' referred to previously in this thread or it's the reed..........not a deal/flight breaker.........once in the air the engine is reliable. And strong as all get out. I'm glad I have some pylon racer experience or this model would be darned intimidating!

Very odd tho' not a hint of a 'miss' on the flight stand but it will miss in the air, but not as bad as before. Dunno, maybe something to do with 'load'? Just gonna fly a few more gallons through it and re-evaluate then...............thanks for all the help............

Doug

Dont focus on the "50-100 rpm" surges. Just adjust the needle for peak rpm and enjoy. the idle will get more reliable as you break in.

also dont focus on the miss or burble that you hear when the engine is in the air. every DLE that ive had experience with does exactly the same thing during the first few gallons. from 20cc to 111cc they all do it. once the engine finally starts to settle though the burble will begin to disappear. my 20 used to do it all the time at about 50% throttle. now its rare enough that it may happen once in every 4 or 5 flights.

in other words, dont worry about it. :P it sounds like it runs just fine. if youre getting a 1600 rpm idle already then sounds like you got a good one. just enjoy the engine. you will like a 17x6 prop on it though. the 16x6 is a little small. mine screams with a 16x6. in fact, here is a video of my 20 running at a variety of throttle settings. let me know if you hear a burble.

The Bee - Dual Video flight 8-15-2012 (4 min 0 sec)

Ha! That was a fun ride! Those U-Can-Do's are great.

Really liked the split screen...........clever!

OK thanks again for the help. As you suggest I'll just enjoy the plane and look forward to it's improving performance..............

Doug

Originally Posted by Geetarjoe

your weed whacker is set to run at a much more restricted throttle range than your dle. its also relatively "dumbed down" with a smaller carb and more forgiving timing and porting that lend themselves for ease of use and easy starting "out of the box" convenience. think about how frustrating it would be if you had to tweak your weed eater out of the box just to get it to run reliably. not many of them would be sold as most people would find it a frustrating endeavor.. so be thankful that you don't have to adjust it.

Yes, and as it was explained to me the other day when I raised this at the field, the performance design and expectation of the weed wacker or a chain saw is universal. That is; every one who uses the tool uses it in the same way, i.e. blip throttle to sustained wide open throttle and return to idle as we walk on to the next weed or prepare for the next cut. Very rarely do we operate anywhere else along the power curve. The model engine with it's wide range of applications, performance demands and load with regard to prop cannot be tuned to serve every situation.

To that, I was using my Echo weed whacker today. I never gave it's performance a second thought. I just used it as a dumb tool. It's a good unit. This afternoon I scrutinized it's performance critically. As critically as I scrutinize my model engines.

At 1/2 and 3/4 throttle, guess what? It burbles and misses like an SOB. Who knew? I suppose if my DLE powered my Echo I'd be very impressed. With that new perspective I must say the little DLE does deliver. Oh yeah.

Originally Posted by AHicks

The ignition thing noted above just makes the thing pickier on it's needle settings, that's all. The high idle hang problem is usually pointing at a lean condition.They like to be run rich on the LS, and they won't stall unexpectedly as easily if you'll do that.

And geez, if you're going to replace the ignition module, don't buy the one for the DLE 30 (#3). It's got the same issue.... get the one for a DLE 55, or anything else running a CM-6 plug. They'll all plug right in and work fine....

What he said!