My suggestion is to install over the outlet tube of the muffler. My first installation was on top of the muffler with the injector right in front of the Exhaust port but I has several flameouts with the pump on at low RPM. After the move to over the exit tube the problem went away...

The stock DL Muffler with an added injector will make great smoke without buying an expensive smoke muffler... Now I do suggest that you have a bung welded to your muffler were you intend to mount your injector. The metal is very thin and won't hold a thread very well, our local machine shop charged me 10 bucks for the effort and it makes for a much better installation...

Good luck,

Ed

Got my DL going this weekend and had a question. As of now, I am running a Vess 23A and needles are at 1.25 low and 2 turns out for the high. I can not get an idle below about 2200 rpm's at this setting-the peak is around 6900 with only 1/2 gal. through the motor/stock exhaust. If I set the needles per the stock setting 1.5 low and 1.75 high, the idle is much lower and top end is still around 6800-6900. Should I not try and lean the low end now and just run the factory settings???????

Thanks

Physically, the throttle arm travel is at its lowest setting and there is no way as of now that I could kill the engine with throttle alone.

You need to run the engine with the right needle settings from the beginning.
After one tank 2500rpm manufacture settings:

Run engine warm at 2500rpm for a few minutes. Close LS needle 1/16 at a time, open throttle, close throttle to idle, repeat up to the point the engine starts surging opening the throttle, then open LS 1/8 and you're right on the spot. After a few tanks run engine full throttle, adjust for max rpm up to the point where it surges after about 30-60 seconds run time, then open HS 1/8 turn or back off about 100rpm. Repeat this procedure for both the LS and HS at least once because they affect each other. Repeat again when you switch to synthetic.

I went from 3 gallons 32:1 mineral to 2 gallons Amsoil Saber 80:1, 2 gallons 90:1 and now I'm at 100:1 100+ flights.

You are set too lean on the low side, the stock settings are after the engine is broke in and this is going to vary some degree with oil mixture . Break in at 32/1 then 50/1 and so on will change your needle settings untill the engine is broke in.

If you are really lean on the low you "might" not be able to kill the engine by closing the throttle plate, either that or it is not completely closing (centered) or you have an air leak. The low needle feeds throughout the whole throttle range also
You do have the idle stop screw removed

From what he said RTk I bet you the stop screw the bad boy.

Stop screw is removed.... I initially ran the motor exactly per the instructions @ 32:1 word for word. The idle and all was good at that setting. After the initial run in, I slowly started leaning the low end until it would die on trans. and then richened back up a little. I then leaned top end 1/16 (from stock) and lost rpm so richened the high speed from factory 1.75 to 2 and it picked up RPM making me think that the stock HS was a touch lean. I guess that I am just paranoid about running too lean and causing damage.

Not sure what to do here...leave @ stock needle setting???

Thanks.

Pulled plug last night and it was brown in color with some wetness on the threads

I have three DL50's and everyone of mine required richer settings on the high end. Based on your plug color I'd say you are probably about right. Fly it, give it some time and you'll need to tweek it slightly as time goes on until it gets broken in.

I have a DL50 that has around 2 gal. through it and have decided I would like to put a Bowman ring in it. I want to know if there is anything I should be doing to the cylinder or piston when I change the ring. There is nothing wrong with the engine, other than I think the compression is a little weak and I would like to fix this now rather than replace more parts later.

Stock settings are only a start. I think you are doing it right. Leave the high speed rich. You're not paranoid, leaving it too lean on the high speed will damage your engine. If not immediately, in time.

likewise, no one would drive their own car just like WRC players if you want it early retired. Same for the engine, decreasing the output in purpose would protects the engine and increasing its life. I have a DL50 and always keep it under 6400-6500 RMP with 22 x 8 prop, so far i didn't find any problem with it. Except for extreme use, like match or championship, otherwise it's unecessary to lean your engine too much only for daily fly or practise.

Complete nonsense. It's very important to adjust the needles for max performance. Not only will you gain more torque and power, also the engine will last much longer because a clean run prevents carbon buildup on the piston and cylinder, and the exhaust won't clog. Furthermore, it's nearly impossible to fly 3D with an engine running rich especially in the lower rpms.

If your engine does only 6500rpm on a 22x8 prop it's really ill and 1000rpm short.

Mstam,

is 100% correct too rich causes carbon build up that will give you lost of power,

Low compression on a DL standard stuff do not change the ring until you have check the compression against another DL and if you still feel that the compression is not the same than change it,

72 Once you started running the engine on orginal ring it has started seating to clyinder. If you change it now then you would have to start all over again. If it ai'nt broke do'nt fix it.

That is what I am asking about. If I change the ring(at some later point) will I have to do anything to the cylinder or just put the ring in and start a new breakin??

If you are going to put the Bowman ring in Then I would do it now. I ca'nt tell you how long the Engine would run before you would have to replace the original ring. Maybe someone has some hrs loged to give us an ideal how many hrs before you will have to replace the ring. As a rule you would have to hone the cly and maybe replace the cly if it has too much ware. These are throw away parts at that time. My question is are you having any problem to warrant changing the ring out.

If the cylinder is Nikasil coated, it ain't gonna wear out for a very very very long time, well, unless you abuse it. The only way to hone that stuff is with a diamond hone.
Nothing wrong with a Bowman ring, they are the best you can buy. Hopefully the cylinders are true, or you might be wasting your money.

72,

At two gallons it's not fully broken in yet. The Bowman rings will not necessarily increase the compression. Your oil ratio effects compression as well. Why change rings if you don't need to?

TOM thats what I have said . If it ai'nt broke do'nt fix it.

What if a person were to put in a Bowman ring right from the start?
Is the quality of the after market ring better than the ring that comes with the engine?
If it is better, and you have one, why not put it in before the engine is even run?

Greg

Frist i didn't see any DL engines killed because of carbon buildup, most of them were killed by crash or pursuing maximum output that causeing a serious potential damgaes, and then you misundersand my idea or maybe i didn't explain it pretty well , i won't lower the RPM by adjusting needles to rich, like your said, adjust the needles for the best mixing proportion is very important. I did adjust the needles for best performance then i lower the highest RPM by servo.


BTW: my engine is not ill, there is no qualitied gas and lube in China, the best RMP i got is 6900-7000 with 22X8, so it's reasonable to lower the RMP to 6400-6500.

If you have no air leaks, the throttle plate is closing all the way, and you can only obtain a good idle by adjusting the low needle, by all means do so. Don't worry if you are a tad rich (especially on the low) it is not going to hurt anything.

By the way, what do you mean you can not find good gas or lube?? I would think you have about the best gas around. I doubt you have the EPA as we do that mandates all kinds of crap be put into our fuel.

Hi!
...Only 6500rpm on a 22x8 ! My MVVS 45cc turns a 24x8 Mentz at 6600rpm.

Jaka-, are both on tuned exhaust??? and tuned properly??

I do not understand,

I have not yet seen any one with a canister system that get's the same RPM that you can using the stock muffler or inverted pits style muffler, I have read that it gives you more power but I havent seen it yet, My DL has a Slime Line inverted pits muffler and I get 7500 RPM with a 22/10 prop, So whats up?