tuavp

Hi to all,

After 2 years I finally finished everything on my C-ARF EXTRA 330L 2.3Meter plane and find time to bring it to the field today. I was planning to run the engine for 2 tank on the ground then maiden flight.

But as lots of modelers experiences my ZDZ super 80 did not started. 2 guys worked on during 2 - 2,5 hours and now they have no chance to use their right arms about a week o more.

Let me tell;

5.5.1 works more less but then no fire. I mean Ignition of choke fully closed full thr, 5-6 flip then choke of , ign off full thr 5-5-6 flip then ign on , thr to idle when we hit it works but only 2-3 second. No more, I checked the fuel lines but nothing wrong, it was choking I could see the fuel was coming to carb but after every 5.5.1 it fired but only 2-3 second.

We tried 10-15 different combinations of H&L needles, nothing changed. 5.5.1 then fires but 2 second then again 5.5.1 fires and stops.

Opened the low end about from 1.5 turn to 3,5 turn and tried every possibilities inbetween and for the H needle as well.

Back home take out the engine from the engine doom and take out the carb(TILLOTSON) opened the inside checked everything nothing wrong, no dirt or thorn gasket etc. Cleaned and put back on the engine, will bring to the field on Friday. I do not have the feeling that it will work.

My Engine stays till I bought on 2006,

So PLEASE TELL & DESCRIBE ME WHAT TO DO ??? SHOULD I CHANGE THE TILLOTSON WITH WALBRO? I HAVE REAL PROBLEM ON MY RIGHT SHOULDER I HAD SOME PHYSICAL THERAPY BUT STILL HURTS THATS WHY 2 GUY HELPED ME TODAY AND I AM AFRAID THEY WILL HAVE LOTS OF PAIND DURING SOME DAYS AS SAID ABOUT ZDZ 80 RVJ

ANYHOW, PLEASE INFORM ME BEFORE FRIDAY(15.5.2009) AND HELP ME BEFORE I THROW THIS ENGINE.

Thks

arobatx

1-1/4 to 1-1/2 open on the low needle, and 1-3/4 to 2 open on the high needle, and it will start. Check your ignition timing (hall sensor position). (See picture) Be sure you have a fully charged ignition battery. Confirm you have spark by holding the base of the plug (while connected firmly to boot) against the cylinder, power on the ignition, and slowly turn over the prop, you should witness a spark when the magnet passes the hall sensor.

rmh

I suspect the carb is th problem
IFyou have no throttle stop (removed to install different throttle arm ) -OR (1) if the ecarb is turned over from original position - the pump feed hole will not suply pumping pressure

HOWEVER -in any event- flipping the prop fast does NOTHING to assist starting.
If th spark is correct (7mm advance pickup to c/lof magnet at top Center) then th ecarb is the problem
I personally prefer the Walbro now used on this engine.
Idid field testing on these engines and the only starting problem was carb related

always insure the engine is not full of fuel from over choking - you may have to physically turn the plane over whilst wiggling the prop

Then insure th efeed hole to carb is in proper position
The engine will choke and run for a short burst even if this hole is blocked!!

With all in proper order - You choke at full throttle for a few flips with throttle open and ingntion off - close down the throttle engage ignition and do a low energy flip
Have done a number ofthese engines -I can honestly say that if all is in proper order -th engine is very easy to start.

when hot do not choke - just set throttle off idle a bit and flip -NOT HARD- for a few times -it will engage
choking it when hot will flood it
set needles at aprox 2 turns each from closed for initial start
this is a rich setting and must be readjusted for proper acceleration .

pe reivers

In addition to Dick's comment, I would add a few drops of oil to the engine front seal AND the rotary valve, to make sure that all air seals work OK.

dirtybird

My Feedback: (5)

Make sure the throttle is rotating the correct way when it opens. looking at the top of the arm it should rotate counter clockwise when it opens.

tuavp

Ok Today I have take out the spark plug and checked the gap and arrange to 0.4mm(o.016'') and re arrange the sensor position checking by the piston position from opened spark plug gap and also checked that the plug sparks. Batteries are fully charged all checked by 1 amp load and all has about 7.80 Mah(Under load) , also change the fuel tank, fuel lines, clunk etc.

Carb was opened and checked&cleaned but nothing found interesting.

Tomorrow I am going to try one more time, I hope it works??? If not , guys start thinking what to do or check more??

I WILL INFORM Tomorrow late afternoon.

Thks for all comments again
Bye[img]

JoeAirPort

My Feedback: (41)

I had a couple of ZDZ 50NG's that I bought new with the Walbro 201b on them. I found that they both needed a lot of priming to start and stay running. It just seemed to run out of prime and crap out. So I ended up doing the priming until I could hear the fuel sloshing around in the cylinder (I think Dick told me to listen for this). Then I would flip a couple more times to make sure plenty of fuel was in there. Also I would start with partial choke on. Then after it would stay running I opened the choke. It always stayed running after that. This worked for me...maybe it'll help you?

Dick will likely correct me but it might be something to do with the rotary valve that these engines need so much prime. I just know I could start easy and fly if I did it my weird way. Once running mine NEVER EVER quit. That was the best thing about them. Transition was very fast too.

tuavp

bad news,

just back from field, again 3 hours we tried everything to run the engine, same things happened again, choke on full thrt , ign off 5-6 flip then choke off thrt full 5 flip then thr to idle ign on first 2 flip it fires but only e few turn 2 second then stop.

Some doesens time it happened the same. We all get mad , I just called to Michal JANOUSEK from ZDZ CZ and explained the situation again he told me that he will send me WALBRO WJ -71 and it will solve the problem. I HOPE SO , NOW I AM WAITING FOR MY NEW WALBRO CARBURATOR. I will let you now

rmh

Janousek is veryreliable to do this
The symptoms you give really suggest the supply hole from engine to carb is not open
gasket or carb location or different isolation block may be problem.

arobatx

Did you happen to remove or rotate the carb for any reason? Do you know about the pulse hole Dick is referring to? The carb, gasket/spacer and rear backplate of the engine all have the hole, and all must line up without blockage.

JoeAirPort

My Feedback: (41)

True, ZDZ's don't have fuel tubing for pump pulse path. It's all internal to the carb and crank case. That would certainly be a problem if the two holes were not lined up.

perche

Hi!

My 80Rvj starts easy with 3-1, an with 1 flip when it is warm.  Well,it used too... not anymore, it starts for 2seconds  after 3 flips with choke on, then nothing.

The engine stopped in the air, and havent started since.

And my arm hurts like h....

So why was the engine so easy to start the 10 first times (new engine) and then all the sudden becomes a hand killing monster?

The first start ever only took 4 flips. I have a walbro on it.  

The ignition?

Thomas

Super08

My Feedback: (2)

Could be the ignition or something moved plugging one of the jets or the pulse hole. Others have had this happen where there was too much sealer used on the welsh plug and it starts floating around in the carb until it plugs something. I had an engine that had some goop inside it that ended up in the pulse hole and blocked it off. Once it was found and cleaned out all was fine. Good luck sometimes it can be a bugger trying to find what the cause is.

dirtybird

My Feedback: (5)

You didn't get some lutefisk on it did you? That would make any engine balky

perche

Hehehe, i HATE LUTEFISK

I hear they use lutefisk at Guantánamo Bay now!

No gaskets on my carb!

captinjohn

Do all ZDZ 50cc & 80cc engines have a rotary valve? Thanks capt,n

Super08

My Feedback: (2)

Yes, the only exception is the 80cc inline twin.

dubs1946

Hi, i have had a simuler experience with my 3W85 i have been chasing bad starting for 18 months, i will be going into details on this in a later post.
The problem was 3W set the timing at 7degrees yes 7 degrees it was a real pig to start and should have been 27 degrees, so check your timing its not difficult.
They had drilled the prop hub and put the magnets in the incorrect place, i had to move the sencer about 1 inch clockwise round the case to get the timing correct, now it starts first flick no fail, boy did i jump and yell when at last i found the problem, and boy did i curse 3W, so go back to basics check the timing first and go on from there.
I also have a Tillitsone carb and it works great no problem.
Good luck and my engine wrecked 3 arms before the fault was found.

dirtybird

My Feedback: (5)

I married a Norwegian girl. One day she brought home some Lutefisk and put it in the garage. The dog took one sniff and barked at it

LeVap

My Feedback: (6)

Hi guys,

I have ZDZ 80 RV-J in QQ Yak 54 101" with JMB TR-80 Canister. Starting the engine is really nota problem for me but I have another one. I can't get it to idle right.
When I start it up it idles good but then after flight when I'm going to land the idle is too high and the plane doesn't slow down for landing. It takes about 20 -30 seconds for the idle to get low sometimes more than that.Sometimes I can't get it down at all and need a lot of runway to land.After I land the idle goes finnaly down. Can some one tell me what I'm doing wrong. Is it in needle set up?

Thanks

Pavel

tuavp

Hi Levap,

First of all you are on the luckiest side inbetween the ZDZ Super 80 owners because you have an engine it starts easily then

When you start the engine let it work lets say 15-20 seconds at 1/2 throtle on the ground, you may hit the thr full a few time, when you are sure that the engine get warm then hit the full thr keep 3-4 second and than back to idle suddenly and wait and watch, if the rpm goes up or still high try to open the L needle a little bit, then try again you will find the exact idle
Do not forget to arrange the high speed needle afterwards accordingly.
I hope it helps to you
Bye

JoeAirPort

My Feedback: (41)

Tired Old Man helped me with this one a long time ago. The idle is higher when the engine is hot. This is normal. Set the idle with the engine hot.

LeVap

My Feedback: (6)

Hi guys,
thank you very much for your answers. But after I start the engine I always let it warm up and the idle is very good. Then when in the air the idle is high and it take awhile for it to go down .Like I said 30seconds or more.Then when I land the plane the idle goes down again just like it was after the start up. So I don't really need to set lower idle I just want it to go down when I throttle down. I tried to open the low needle a little and it helped but the transition was not good so I closed the low needle a little and then I had the idle problem again. So I don't know what to do.

Pavel

Super08

My Feedback: (2)

I am starting to wonder if you have some type of cowl effect causing it to go lean in flight causing the high idle????

LeVap

My Feedback: (6)

Hi Super08 ,

I don't know but if I let it fly on higher idle for about 30-60 sec the idle goes down.

Pavel