ZDZ & RCS Support Direct support from Mike Dooley of RC Showcase for all your ZDZ and RCS Engine questions.

ZDZ50NG starting

Reply
Old 12-05-2005, 08:39 AM
  #1
juanes1969
Thread Starter
 
Join Date: May 2005
Location: Comayaguela, HONDURAS
Posts: 409
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default ZDZ50NG starting

Mike, I´ve been having a problem with my 50NG:
When I try to start it the first time on the field it starts easily, but when it´s time to start it the second time, and after many flips, I´ve had to take the spark plug out, dry it and reasemble again. After drying it, it starts on the first or second flip. My shut off procedure might be at fault, but I´ve tried two procedures:
1.- after flying, bring down the engine to a very slow idle and then shut off the ignition
2.- just bringing the idle trim to 0 and cut all gas to the engine, after it is off, shut off the ignition.

But the two ways I´ve been using seem to flood the spark for the next flight.
I´ve been getting 6780 rpms with the bambula 20x10, I don´t know if I can colse the high needle a bit more to get a few hundred rpms more, can I? I´m flying at 3000 feet above sea level so I do not know if that is a good rpm for the engine.

Well, on the flooding problem, what can i do?
Thanks in advance
John
juanes1969 is offline  
Reply With Quote
Old 12-05-2005, 10:39 AM
  #2
Mike Dooley/RCS
 
Join Date: Jul 2002
Location: MD
Posts: 515
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: ZDZ50NG starting

recommend you do not choke for subsequent starts, depends on the muffler you are using, with the Supersonic brand we see at least 7200epm, with the BCM brand it is about 400rpm less. At 3000ft you will be approx 10% power loss, so keep this in mind as well.
Keep me posted.
Thanks,
Mike Dooley/RCS is offline  
Reply With Quote
Old 12-05-2005, 10:52 AM
  #3
rmh
 
rmh's Avatar
 
Join Date: Dec 2001
Location: , UT
Posts: 12,630
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: ZDZ50NG starting

just to add-
when you shut down any gasser with the low idle -- you effectively "choke" the engine.
So restarts are sometimes a problem-
but with idle needle properly adjusted and if the restart is say - 15 minutes later - the engine is usually ready on first flip.
Also the setting of the idle speed (throttle stick) can screw this up - the engines prefer a low idle speed for restart.
The idle needle typically wants to be as lean as possible -without having the engine gasp when throtted up - WARM-
we have 40/50/80 ZDZ and they all like this same setup
For that matter the other brands of engines we have setup for friends - are the same way.
rmh is offline  
Reply With Quote
Old 12-06-2005, 08:33 AM
  #4
juanes1969
Thread Starter
 
Join Date: May 2005
Location: Comayaguela, HONDURAS
Posts: 409
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: ZDZ50NG starting

Mike, on that power loss, when the altitude is higher, does it mean that i will loose 720 rpms or i can always get the 7200 but less air moving from the prop?
As I said, I´m getting 6780 rpms and would like to tune the needles to at least 7000, will the engine give me 7000 and the power loss is the thinner air, or am I getting too many rpms already for my altitude?

Now aon the other hand, will it impove if I change the prop for a 22x8 bambula, or should I stay with the 20x10?
If I change to the 22x8, how many rpms can I expect?
I´m using a supersonic muffler that I ordered with the engine, I feel it is better than the bisson and less restrictive.
I´m not choking the engine but only on the first start.
Thanks
juanes1969 is offline  
Reply With Quote
Reply


Thread Tools
Search this Thread
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -8. The time now is 05:57 PM.