srm99

I was a beginner to gas 6 months ago and i got the wrong advice i baught a cheap motor a crrc after people siad it was a strong motor unfortuatly i never found out i had every possible prob and recieved backyard service after 6 months i was only able to fly 3 times and i had to land as the motor had problems alot of them.
in the end i got angry and returned my motor then i baught a da 50r as i wanted to do 3d in wm wh 300 extra in the future i thaught about the zenoah 62 but i wanted to save weight by buying the da i can save nealy 1kg .
my decision was da has a good name in 3d because its light .
if u want to do 3d stuff look at a light well name brand dont get caught as i did i started to hate gas engines because of this experiance .

LSP972

My Feedback: (13)

I know the feeling.

sillyness

My Feedback: (25)

There's a thead on here about at a G-62 lite that looks interesting, BUT... it says the cost is $525 by the time the conversion is done... and it's still almost a pound heavier than some other 50cc motors out there for about the same price. A pound in a 50cc 3D ship is a huge deal... people spend hundred on caron fiber to shed fractions of a pound.

phaebes

My Feedback: (1)

I am a newbie dummy to gas as well. I have recently purchased a Roto 25 that came with minimal instructions. It's got a Walbro carb, so I believe that the setup should be similar to other gassers--but nothing came with the engine to refer to. The throttle is easy enough to figure out, but the mechanics of the choke have got me befuddled. When I fully close the choke with my hand, which is spring loaded, the choke's lower arm engages the lower arm of the throttle and the two lock on. Both the choke and throttle are closed, but the choke can now be opened or closed independant of the throttle. But, when the throttle is moved (as it is supposed to be for starting, at 1/4 open, according to RCS) the two spring loaded arms unlock with a snap, and the choke goes open 100%--which makes sense, i.e. that the choke has to be open in order for the throttle to work properly. So how do you keep both the choke closed and the throttle partially open at the same time? (I have a feeling that the answer here will be embarrassingly simple).

The throttle 'arm' is spring loaded. I want to remove the spring to relieve the throttle servo, but I think that the spring should remain as a spacer for a ball link that I plan to use. Is this OK?

Finally, I am planning to use 3/32"D Tygon fuel tubing. I assumed that because this is a small engine, that would be the correct diameter. I have never liked the wire fuel tubing ties for glow, as they seem that they could easily cut through the tubing. What type of ties do you use for gas?

So many questions...

srm99

IT sounds like the choke is connected to the throttle cool idea how it should work is when u choke it u can put a little throttle to turn of choke without restarting the engine
what happens with other motors u put the choke on then when it pops or fires u stop and then turn off the choke and restart ,
it is really hard to start a cold petrol motor the choke is to make extra fuel in to create heat so fuel can vaporise and create combustion then run normal .

Antique

My Feedback: (4)

Gotta keep reminding the "experts" some FACTS...NIB G62 from Ebay, $264.95
Ignition conversion, $150 mechanical advance..$175 electronic advance..
Total cost less shipping, $414.95 or $439.95...(Horizon and Tower must really love this)
Total Weight, 4 1/2 lbs less muffler mechanical, 4 lbs 1 oz electronic...A 2 oz 850 ma battery, $13..will run for at least 2 hours on that one...
No break in required, run it on the ground as long and hard as you want..
Use a 22-10 or 24-8 prop, thrust around 28 lbs...

Rcpilot

My Feedback: (78)

I've got a few Walbro carbs that work in the way you describe.

When that choke lever ratchets over and catches on the throttle lever--they are both locked at that point. Only way to get them unlocked is to work the throttle a bit.

It works fine. When the choke lever engages the throttle lever, it's actually cracking the throttle butterfly just a tiny bit. You may not have noticed the throttle lever moving to open a bit, but it does.

Just turn on the ignition and then choke it. Flip it a couple times untill it tries to run or barks once. Then work the throttle lever to dis-engage the choke. Now set the throttle to idle and flip. It should start and run.

On this particular carb, I'd leave the springs on everything. It's not that much load on the servo. No more load than any flight control surface. Yes, it wil put a load on the battery, but I wouldn't worry about it.

Or, you can take the springs loose from both the throttle arm and the choke arm. Leave the spring in there to act as a spacer, or the butterflies will vibrate inside the carb and wear it out. Just clip the little hook on each spring so that the arms can move freely, but the spring is still in there to act as a spacer. NOW, you'll have to hook up a throttle servo AND a choke servo. Just run the choke servo to a switch in the TX and then you got a way to remotely choke your engine AND it can be used as a shutdown device when you need it.

3/32" tubing is fine for a 25cc engine. Don't forget, these engines have a pump in the carb. It will forcibly suck fuel through the tubing. A Glow engine needs larger tubing to lessen the "load" that the non-pumped carb sees. A glow engine needs larger tubing to allow a free flowing course for the fuel. Gas engine doesn't care. It sucks fuel with a pump. Put the fuel tank in the tail. Put it wherever you want. I use 3/32 for engines up to 50cc. Works fine.

To keep the tubing on the brass tubes in the tank:
I use neoprene fuel tubing on my clunk. It stays flexible longer than the yellow tygon. Tygon gets stiff after a year and then the clunk won't flop around like it should. Neoprene is black and looks almost like rubber.

You can scuff the brass tubes with 100 grit sandpaper. Then put a drop of solder on the brass tubing. That will act as a barb to help keep the tubing from slipping off. If you spit on the brass tubing or spit inside the fuel tubing before you push it on the brass lines, it helps lubricate things and makes it slide on easier.

Outside the tank, I use 4" zip ties on my fuel lines.

sillyness

My Feedback: (25)

That's way cheaper than I saw a guy bought his for... sounds like a good deal. I can't say that Ebay is the first place I would go shopping for an engine. Also, how are we to know the prices of your conversions? They are not posted on your website that I can find.

Nice stab. I'm getting really sick of condescending attitudes on this board just because someone might have a different opinion than the builder of a conversion kit. While I do respect your work and your knowledge, I don't always think that it is the best solution for a particular application. I do know the numbers and I have seen the difference on my own aircraft... a pound is a pound. Being sarcastically called an "expert" for my experiences is just plain rude. At this point I wouldn't buy a kit for $10.

Cheers

Antique

My Feedback: (4)

The Ebay engines are NIB, no prop hub..Might be the reason he gets around Horizon..
They are the same exact engine, $424.95 unconverted from Horizon or a LHS...
The experts I was referring to are the ones who always seem to know about engines they probably have never owned or run...sorry if you took it wrong...
The $525 G62s are engines I buy from Horizon and add the cost of conversion, or engines sold by BH Hanson with my conversion...Would not be fair to sell engines for less than he does, same goes for the G26...
Some applications need a heavy engine, so stock is better on those...
My website has the prices, click on forum and then on ignitions....

phaebes

My Feedback: (1)

Thanks for the GREAT information, Rcpilet. Thank you. I really like the idea of an on-board choke! Interestingly enough, I just read the Wild Hare intro to gasoline model aircraft engines on their website, and in the paragraph about the need for a kill mechanism, they state: "This can be a servo actuated ignition switch, an electric ignition switch, a fuel cutoff, or my favorite, a servo actuated choke. This solves two problems, how to operate the choke with the cowl on and how to kill a runaway engine."
[link]http://wildharerc.com/Downloads/downloads.html[/link]

phaebes

My Feedback: (1)

Thanks for the GREAT information, Rcpilet. I like the idea of a servo-controlled choke. Interestingly enough, I just read the Wild Hare intro to gas engines on their website, and in the paragraph about the need for a kill mechanism, they state: "This can be a servo actuated ignition switch, an electric ignition switch, a fuel cutoff, or my favorite, a servo actuated choke. This solves two problems, how to operate the choke with the cowl on and how to kill a runaway engine." Having the option to kill with the choke while in the air is a good thing.

[link]http://wildharerc.com/Downloads/downloads.html[/link]

In my 1.20-sized GP Super Chipmunk, it's going to be interesting to try to keep the radio components 12" away from the electronic ignition. I have read some posts about some types of tubular shielding for servo and battery leads. Are these worth looking into?

sillyness

My Feedback: (25)

Sorry I was a little touchy... bad week for me.

Anyay, I will likely be getting a G-62 in the future for use in a tug type application... should work pretty well, plus you can't beat the durability. I'd LOVE to put a big GS Race plane together... the idea of a huge gasser built just for speed seems so cool... but I gather those fellas crash a lot in the races... more into flying than building. Oh well.

Cheers

jw637362

My Feedback: (1)

Sillyness - Proof is in the pudding as they say. Yes it is stock, 21 lbs Carden Extra 30% - Knife edges Great and enough pull out power from flat spins, second image and inverted flatspins.
I think By stating the comment of not for 3D ships will tend to teach people not to purchase Zenoahs for basic aerobatic ships which are also 3-d capable. I love my setup