nmking09

My Feedback: (61)

Ok, I have a Zenoah G-62 and I have been trying to start it for the past two nights. I am using the carb, brown (realigning) block and am trying to start it with a 21in bolly prop. I can get it to pop almost every time I flip the engine but it wont keep running. It sounds as if the choke is on. Yes, I have checked the choke and the carb they are both working fine. I read somewhere that it may be due to the prop not having enough angular momentum to continue to the second firing. I will try a bigger prop in a few nights, after my arm quits throbbing, any other suggestions in the meantime?

Thanks
Nmking09

Dr1Driver

You're trying to prop it by hand? Forget that. Get a B&B spring starter or a big enough electric starter. A friend of mine had a G-62 with standard ignition that never did in 5 years start by hand. We always used the B&B starter.

Dr.1

PS Be sure the relaigning block is on correctly.

hankpajari

My Feedback: (1)

There has been a lot of discussion on this lately. Has to do with where the prop is in relation to the magnets on the flywheel. You need to make sure that the flywheel is moving before the first magnet goes under the magneto. You can probably find this with a search. I believe that the last discussion even had a drawing of where the prop should be mounted.

hvac

My Feedback: (7)

i have had my first gas airplane about 2 months now. it is a sukhoi 29 with a zenoah g 62. i run a 22x6x10 wood prop. when i first tryed to start it it would do the same as you are describing. pop but not continue to run. first thing i would say is buy a spring starter. they are only about 50 some bucks, although i do not have one on mine. i have finally figured out how to start mine by hand. first use a dollar bill and fold it in half and use it to set the gap between your source coil and magneto. then turn the engine over by hand until you feel the first part of the compression stroke. set your prop so it is at 1 oclock and seven oclock and tighten there. use a choke or use your finger over the carb inlet and prime the carb until fuel is pouring out of the carb. with the prop at 1 and 7 use a thick glove and smack the prop hard. after the first choke on the carb and about 4 smacks on the prop prime it again until fuel is pouring out of the carb, set your prop again and smack it hard. mine now starts on about the second smack after the second choking/priming of the carb. if you are getting pops then your plug is ok and your carb is probably ok. dont worry where the magnets are on the mag in relation to the source coil. it is more important to set your prop at 1 and 7 at the beginning of the compression stroke, prime/choke the carb and smack the prop dont grab it and flip it. my engine is several years old and i bought everything used, but after going over everything it flys great and the motor runs excellent. high speed needle set a about 1.5 and low end set at about 1 1/8.

davidm

My Feedback: (18)

Jump Start from C&H is the way to go. Use to be around $60. Much better than a spring,it changes the timing just for start and makes it extremely easy to hand start. It uses 4 AA bateries that can stay on board or you can detach after starting.

David

multiflyer

The G62 hand starts in a few flips every time - IF THE SPARK PLUG IS CLEAN! The classic indication of a a plug that is starting to foul is pop only but no run when hand propping. A pop does not mean the plug is good. Mine fires in 3 to 7 flips every time until the plug gets a little dirty. Usually cleaning it brings it right back to life. Always keep a new one with you to check for this.

To hand prop a Zenoah, you can't start at compression. You have to start before compression for the magnet to make a good spark generating sweep. I set the prop so it hits compression at the 1-o-clock position. Then start your flip from the 4-o-clock position. Hitting compression at 1-o-clock is perfect arm positioning. Just push right on through.

The CH Jump Start works fine but one problem, it is not fail safe. I have seen these go bad during flight more than once. Since it is permanently installed in the hot lead, it causes the engine to lose major power and/or quit. Not fun on an expensive scale bird. A buddy solved this by altering the connections so that the Jump Start module remains external. Requires extra plugs but when removed after starting, is completely removed from ignition and can not cause problem in flight.

The Spring start works fine if you don't wind it up too much. Half turn only. And grease it up every now and then. Mine hand starts so easily (with clean plug) I just removed the spring start. Saved some weight and made a few bucks selling it.

multiflyer

nmking09

My Feedback: (61)

Thanks a lot for all your help fellas. Glad to see that I wasn't the only one who experienced this. I think I was trying to start it too close to the compression stroke.

I have just one more question. When you say "smack" do you mean slapping the prop, and how hard? It seems like you risk breaking the prop. Has that ever happened? Thanks again for all your help. My arm is feeling a bit better. Now if only I could finish my homework so I can give it a try again. I'll keep yall posted.

Nmking09

hvac

My Feedback: (7)

with my prop set at 1 oclock right before compression stroke i slap the prop with a good follow thru. with a gloved hand about 1 to 1.5 feet away from the prop smack it like your going to slap a person(excuse the example, please) and follow thru like throwing a baseball. it will not break the prop and gives more rotation than grabbing and flipping it. works for me everytime.

Tired Old Man

My Feedback: (1)

Withou trying to be a S.A. in any way, the Zenoah manual notes the required prop position for hand starting. There really is no need for spring starters or electronic ignition assists if those directions are followed. It makes good business for the manufacturers of the add on's if the directions are ignored, though.

nmking09

My Feedback: (61)

Ok, Ok, I went back and actually tried to understand the instructions. and yes they do say that you need to flip the prop before the compression stroke begins. As a matter of fact there is a diagram of how I was trying to start it, with a huge X across it.

I haven't had a chance to start it this week because the last time we tried to start it the throttle linkage came loose. So, as soon as I get the parts in, i'll try it again.
Thanks again fellas
Nathan

multiflyer

I do not recommend slapping at the prop. That isn't necessary. Just begin your flip well before reaching compression. This is the important point to remember. Your hand will be moving fast enough to push through compression if prop is mounted at the right orientation. YOu do need to flip fast enough to generate and adequate spark.

Multiflyer

Diablo-RCU

My Feedback: (1)

All magnetos have weak spark at low rpm. The strength of the spark increases with rpm. That's why you need to get the prop moving quickly to get a decent spark to start it. Electric starters get the prop moving easily. The jump start provides a hot spark at low rpm. Electronic ignitions also provide a hot spark at low rpm, and also have the advantage of retarding the spark timing while starting and providing an advance curve for power and smoothness.

nmking09

My Feedback: (61)

Ok, update: switched the prop to a dynathrust 22x10 (yes i know they are horrible, but i'm just going to use it to begin with).

Engine started this evening fairly easily, but there is one problem though, the first is that the engine will not idle, at all. It will run at around 1/2-3/4 throttle but once it gets below that it dies. and moving the needles seems to do nothing.

The second problem is that, when it is running, it seems to be trying to seek an rpm. I know in glow engines this tendency goes away after sufficient run time.

I am most concerned with not having an idle, this would probably make landings a bit hot.

any advice would be appreciated. (and no i am not going to buy a DA 50, I'm in college).

Thanks
Nathan

Antique

My Feedback: (4)

Classic case of the throttle opening backwards...Look in the carb, with the throttle closed you should see the threads of the screw that holds the disc to the shaft..If you can see the head of the screw you need to take the arm off the shaft and re position it...
This will fix both problems...

multiflyer

A backwards swing to the throttle butterfly could be the problem. It is easy to do if you are not paying attention. You will notice that the butterfly does not close off the throat as well if rotated the wrong way. The G62 is a very smooth running engine. Basically they work well or something is wrong.

Multiflyer

jbflier

My recommendation is to get an 18volt cordless drill, a large Miller type cup and spin away. Works great for me.............

nmking09

My Feedback: (61)

Thanks a lot for the help so far fellas, I'll get it running right one day.

In the mean time I have another question. It is highly likely that that is the problem.

If you are looking into the carb which side should go back when you throttle up (the front side or rear)?
Also which side should the butterfly vents (those two scrapes on the valve) be protruding from (into the engine or out of)?

Thanks
Nathan

Antique

My Feedback: (4)

Take the carb off the engine...Look at the side that goes against the engine...Close the throttle..you should see the head of the screw that holds the disc...the edges of the disc are beveled..when the throttle is closed the beveled edges will touch the bore all the way around..There are 3 little holes in the side of the bore..The disc will open towards the little holes as the throttle is opened..

nmking09

My Feedback: (61)

Ok, assuming i have the valve oriented right now. I should see the screw head when I am holding the carb in my hand. The butterfly valve should the have numbers on it facing me, and there should be a cut out on the valve, on the side with the little holes in the bore, the side that the valve opens to.

Ok my next question is how in the world do you set this carb up to work, without using a bell crank? Again, I have already installed the carb rotation device?

I also need to add that it appears that this engine is a bit older and dosent have the nylon throttle arm. Mine is metal and closely resembles the choke arm. Is there a way I can remove this arm, and flip it or install the nylon arm? Also, where can I get a nylon arm?

Thanks again
Nathan

nmking09

My Feedback: (61)

Almost a year later...
What I did to help the throttle orientation situation was to invert the butterfly and cut off the Idle limit screw arm. This allows the butterfly to open properly and at the right orientation for easy throttle pushrod instilation.

The downside to this is that I don't have a Idle limit. The upside is that now I can kill the engine from the radio using the throttle, just like a glow engine. I also use the throttle kill to help with breaking on landing.

So far I have about 20 or so flights on it and it works great! Very strong puller, runs like a top. Starts very easy (if you clean the plug first). I am very pleased, can spin a 22x10 dynathrust at 7600. Great motor.

Thanks again guys
Nmking09

bdelmonte

My Feedback: (4)

I am trying to figure out a similar problem with installing a throttle pushrod cable for my G-38. It appears that I need to also cut of the Idle limit screw arm bracket to fit a rocker arm on the throttle arm with the butterfly in the carb.

Do you have any pictures to post on your set-up here?

Bryan

Antique

My Feedback: (4)

Here's one way

Tired Old Man

My Feedback: (1)

Ralph,

I think you're going to need to increase the size of that picture before you upload it again. It opens to the same size as in the post. Then again it could be exported to a desktop or something by someone that wanted to open it up with any of the photo viewing programs and enlarge from there.

Antique

My Feedback: (4)

Computer illiterate

bdelmonte

My Feedback: (4)

Thank you for the picture (it is a bit small).

I bought the Zenoah carb kit, but the rocker arm does not fit the throttle arm due to the idle stop screw interfering here.

Should I cut off the mount for the idle stop screw?