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Zenoah 45 poor throtling

Started by F6F RD, February 04, 2018, 15:34:52 pm

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F6F RD

Hi All
I have a Z45 fitted with an RC Excel ignition unit. The engine has run fine for 18 months until it dead sticked in the air.
So i have re plumbed the tank, stripped and cleaned the carb, new gaskets and disphragm. New plug as well.
Managed to get it running today, but its very lumpy at the bottom end and will not pick up, it just cuts.
I have tried everything with the needles but no joy.
I did manage to get it past tick over once and the top end seems fine. It also seems to start ok as well.
Any advice?
Thanks
Richard

dart16

Have you tried a different ignition battery?

F6F RD

I have just checked the battery, and it was down to 4.9v
Its a 4.8v 2000mah nimh, i charged it last night as well.
Just put it back on charge to see what it will take.

dart16

sounds like it is not the battery then - I just remember I once had an issue with one of my RCGF's spluttering and dying, then difficult to start and eventually (after all the usual fuel related fixes didn't work) it was suggested I should check the ignition battery and sure enough it was one cell down under load...

F6F RD

Well i charged the battery and it only took 250mah and 1 hour according to my charger. If it was down to 4.9v i would of expected it to take longer.
Think ill try a new battery next, i will have tried all the cheap options then. Only the carb and ignition unit left then. Alternative is to convert it back to the magneto version.
Richard

CEEJAY

Hi Richard

sounds like you have some blockage in the carb filter, it will entail some delicate work so get carb off and onto nice tidy bench. inside the carb cant picture in my mind which side but, theres only two, you will find a small mesh filter that is "pressed" into a reccess you will need to very carefully remove this (i have used a pin or needle, note which way it fits, its concave amd only goes in one way) if you hold it upto the light in all likely hood you will see its full of fluff and gunk, bung it in a small tub of clean petrol and a gentle clean with a small brush and a light blow through, then a wash out with more clean petrol should do it, carefully reasemble and fit carb

  i have had this happen on quite a few of my zenoahs, and got this little tip from Ian,

of course if you have tried tjis then it could well be electrical at which point yer on yer own matey!!     :af :af

chris
I know THE answer!!......................42

F6F RD

Hi Chris
I have stripped the carb completely including the mesh filter and it looked ok. I even sprayed carb cleaner through all the jets and orifices. Think ill try the battery next, if that fails im not sure.
Richard

itsme

Quote from: F6F RD on February 05, 2018, 08:53:29 am
Hi Chris
I have stripped the carb completely including the mesh filter and it looked ok. I even sprayed carb cleaner through all the jets and orifices. Think ill try the battery next, if that fails im not sure.
Richard
I had similar problems with a 38. Complete new carb kit, with all the gaskets etc replaced and no better. Replaced the entire carb with a cheapie Chinese one and it was an instant cure. This was a mag version though.

CEEJAY

oh! well

  trouble is i,m told there are some realy fine 'oles inside the carb and ifn they get blocked there be sid all you can do but try another carb,  $%& $%&

i,m sure a man of you caliber will sort it :af

chris
I know THE answer!!......................42

British Victory

February 05, 2018, 15:03:05 pm #9 Last Edit: February 05, 2018, 15:04:12 pm by British Victory
I'd replace the battery first. (FWIW I changed over to LiFe over two years ago and I just checked one of the few nicads I have left (a sanyo 4 cell) that hasn't been charged in over a twelve month and that reads 4.71 Volts.)
I'd try another plug and, if you still have the means to do it, try it on magneto. If the engine doesn't respond then it must be your carb, if it does respond it's your rc xcel module.
I had a similar issue with a turnigy petrol job that disappeared after I put a new plug cap on it as the screening for the plug lead was fraying, also check the little spring is inside the plug cap.
HK used to do spare plug caps for about a fiver, I also bought a spare rexcel module but never used it yet.
Good luck on it anyway, on the bright side, if you can fix that you'll have no probs with a BSA Bantam :''.
there's only one f in RCMF,
               John

British Victory

As I was typing my earlier post, I popped that nicad on the charger, it now reads 6.36 volts and it took 88mAh in 11 mins and 29 seconds and says its full. Would you trust that battery?
there's only one f in RCMF,
               John

FrankS

Not an ignition battery, but I had a 4cell AA eneloop RX pack that would drop voltage and shut down the radio if any significant current (i.e. more the 200 ma) was drawn, resting voltage was 5.6v put 0.5A on it and it dropped to below 4 volts.

British Victory

Frank, that's why I quit using NiMh batteries I changed over first to good old nicads then life batteries which I use 2 cell ones directly onto my equipment with no adverse reactions.
As  a matter of interest, the battery to which I previously referred, a 1000mAh 4 cell nicad, ran a discharge on it and it cut out after 29mA at 4.44V, then cycled it and it's now sitting at 7.00 volts (4 cell nicad!!) and took 1060 mAmps to shut off.
I still don't trust it.
But all this thread burgling doesn't sort the OP.
there's only one f in RCMF,
               John

F6F RD

Thanks for all the replies, the battery im using is an Eneloop by the way.
Does anyone know if a LiFe can be used on a RcExcell  ignition?
First job at the weekend is to try another battery. Im happy the carb is ok, so ill go cheap early with battery.
Richard

F6F RD

Just a side note,
Just been tinkering with the 45 and i notice fuel in pulse line, never seen that before and also fuel is seeping out of the throttle are.
Never have trouble with my Lasers😕

F6F RD

Just taken the plug out, and its quite black with some black oily goo. It was a new plug yesterday.

itsme

Carb is obviously faulty. Clean it again and try some high pressure air through it, replace all the gaskets and springs and check the diaphragm for leaks. If that does not work, replace it....Look on ebay at garden tool spares and you should find a Chinese equivalent to that carb. You may have to remove a few bits of metal as we did with the 38 carbs, but they work faultlessly. And around £18 compared to £80 for a genuine one.

dart16

February 06, 2018, 11:04:29 am #17 Last Edit: February 06, 2018, 11:11:04 am by dart16
Quote from: F6F RD on February 05, 2018, 19:13:04 pm
Thanks for all the replies, the battery im using is an Eneloop by the way.
Does anyone know if a LiFe can be used on a RcExcell  ignition?
First job at the weekend is to try another battery. Im happy the carb is ok, so ill go cheap early with battery.
Richard


Straight from the horses mouth!

https://hobbyking.com/media/file/369367123X109995X57.pdf



So the answer is 'it depends'.. :)   I have used 2 cell LiFe packs on my RcExl ignition systems for ages without a problem ( without a diode or regulator) but I must also say I tend not to run the engines flat out for any appreciable time....

F6F RD

March 11, 2018, 14:28:32 pm #18 Last Edit: March 11, 2018, 14:29:44 pm by F6F RD
Hi Folks
Thought i would get back and report on the Z45 issue. Since the old carb was leaking fuel at the throttle shaft, decided to buy a new carb. Also fitted a new ignition battery as i think the eneloop pack wasnt responding well after charging.
Glad to say the engine is back to normal, just ran it for 30 minutes and its spot on. Started very easy, tick over was perfect, also ran it with the cowl on just to be sure before i go flying. Happy days.
Richard

itsme

Quote from: F6F RD on March 11, 2018, 14:28:32 pm
Hi Folks
Thought i would get back and report on the Z45 issue. Since the old carb was leaking fuel at the throttle shaft, decided to buy a new carb. Also fitted a new ignition battery as i think the eneloop pack wasnt responding well after charging.
Glad to say the engine is back to normal, just ran it for 30 minutes and its spot on. Started very easy, tick over was perfect, also ran it with the cowl on just to be sure before i go flying. Happy days.
Richard
Sometimes it is easier just replace.... well done!