DLE 35 RA Mods- Reed Valve, Bowman Ring, Single Post prop adapter

[Steve_B]

FWIW.. Better sealing on the reed valves doesn't actually increase the suction through the carb. The reed valves are just a non-return valve, the suction is caused by the piston moving up and drawing air into the crank case through the reed valve (reed valve is open during suction so sealing is irrelevant).

It will help with starting and low down power though because a badly leaking reed means that as the piston comes down, some of the fuel/air charge that's just been sucked in gets blown right back out through the carb. This loss of the fuel/air means that you get less pre-compression in the crank case and not as much air and fuel gets pushed up the transfer ports into the cylinder, meaning less compression in the cylinder and less power.

2 stroke engines are just brilliant pieces of engineering, so simple yet so effective.

 

[dth7]

Better explanation for sure! Never claimed to be expert on these engines. Learning with each post thanks to guys like you responding. Flush fits and sealed leaks can only help in overall performance. I can't wait to stop talking about it and actually get out and fly the $@"" out of this thing!

 

[dth7]

Throttle Servo geometry? Little help? Any hints or easy procedures for setting up throttle servo? Thanks

 

[dth7]

Ok, I'm back and finally maidened the 78 with the DLE 35. Here's the run down on the days events if you're interested- http://www.3drcforums.com/showthread.php?1002-78-Extra&p=40891&viewfull=1#post40891

Quick tech notes- DLE 35, stock muffler for break in
Xoar 20x6 Laminated
initial max RPM- 7400
5 flights max- 7600-7700
Required minor adjustments from recommended settings and ran smooth and reliably all day (if you don't count a failed throttle servo- no fault of the engine).
Starting- initial using manufacturer's technique- choke with full throttle til pop, choke off and throttle just above idle worked OK with some minor adjustment to throttle settings. We started using more like 1/2 throttle and it was fine. Initial full throttle is to pull the fuel into the lines and wet the reeds. Hot starts still required a quick 2-3 flip choke but worked fine. Very pleased with engine.

After another gallon or so, should have that done this weekend with a big tri club fly in and the fact that this just turned into "Mr. Go to plane!" If I had a filler tube long enough I could fly this a Looooong time! I'm worried about puffing batteries on my electrics now!

Will update as break in comes along and when we do the pipe. I'll try to document that with photos too. Fly low, fly hard, have fun!

 

[dth7]

About 1 1/2 gallons through the DLE 35RA now. Probably 12-15 flights. It really sips the gas, about 1oz/min or less.
I've altered the start procedure a little from the manual and it seems to work great.
Manual- choke- on, throttle- full, ign- on, pop. Choke- off, Throt- just above idle to start.
Now- choke- on, throt- cracked, ign- on, pop. Choke- off, Throt- cracked til start.

This new method works averaging 2-3 flips to pop then 2-4 to start.

We have not touched setting since first day and I've been flying with a high (~210 rpm on grnd) and low (~180 rpm) idle set to a switch. The last couple flights I've been running on low idle with no indication of wanting to fail, even in spins.
I plan to try the CF Hover 20x6 prop next week before the IMAC competition.

After the IMAC next weekend we'll be piping it with the CF 40 pipe. More to follow. Stay tuned!

 

[SnowDog]

Great report - really like the idea of a high/low idel on a switch! I may have to try that one myself!
Good luck with IMAC!

 

[dth7]

Great report - really like the idea of a high/low idel on a switch! I may have to try that one myself!
Good luck with IMAC!

Thanks. I got the low high idle from Matt (Enterprise) and its a real help for break in where you want a little buffer on the low side but you can switch down to a landing idle. It's a throttle throttle mix then pick your switch. The DLE is running nice at the low idle now which helps with the power off stalling maneuvers.

 

[dth7]

DLE 35 update- Going strong and reliable after 1 3/4 gallons. I switched to a CF Hover 20x6 and the response was better. It's running a little rich and I plan to tweak just a bit today. I don't want to mess with it too much before the IMAC event this weekend. Starts are very consistent- 1-3 flips on a low idle setting for pop then 1-4 flips to start on a low idle setting.
talk soon.

 

[dth7]

All broken in. Still using up my 32:1 Penzoil air cooled mix before going to synthetic Stihl Ultra.
Put the pipe on. Starting with the ES 30 CF at 32" from cyl to end of cone (based on a friend's experience). Quick n dirty tune today (had to beat some rain). Flew it. Max was about 8400 rpm, mid range a bit weak. Definitely needs tweaking. A little quieter and starts are even easier! More soon.

 

[dth7]

Piped and set up to about 32 1/4" on the ES 30 CF pipe. still on Penzoil til it's gone. Will retune on Stihl Ultra and put the new cowl on. Real clean fit with the header. WEnt from 7800-7900 rpm on a Hover 20x6 to 8700, really ripping it. Will have to try a 20x7 or 8. Going to try the Xoar 20x6 laminated tomorrow. Starting easy and running great.