Newbie gasser seeking help! (try again) How are gassers different from glows?

[OldSchool]

Dear sirs,

I just got a used gasser (x cell 60) without any manual. It has a
Zenoah (sp?) engine and graphite body. I am somewhat familiar with
glow heli's (I've been flying them off and on for about 5 years).
There are some things on the gasser that I just don't recognize...

The gas tank is not pressurized? What is the extra hose for?
Overflow?

There is a metal "thing" on the side of the heli. Two thick wires go
into it. It almost looks like a heat sink or some sort of ground.
Any ideas?

What is the best way to start the motor? Do you have to prime it?

What is the best oil to use? Ratio? Source?

What are the 3 set screws on the carb for? Mix? How do you set the
mix? How do you know if it is rich or lean?

How bad is overheating? Does this mean it is too lean?

What type of antenae is best? The standard wire? Dean's short
antenae?

What is a good source for gasser fuel tubing and other gasser parts?

MOST IMPORTANT...does anyone have a manual for the heli or engine that
they can send me a copy of?

This is a lot to ask...but I am really lost. Starting to regret this
endevor...

Thanks much!

[Rhodesst]

Hello OldSchool,

>Dear sirs,
>
>I just got a used gasser (x cell 60) without any manual. It has a
>Zenoah (sp?) engine and graphite body. I am somewhat familiar with
>glow heli's (I've been flying them off and on for about 5 years).
>There are some things on the gasser that I just don't recognize...
>
>The gas tank is not pressurized? What is the extra hose for?
>Overflow?

The carburator on the Zenoah is a pumper carb. You should notice a short piece
of tubing that runs from the engine crankcase directly to the carb. This uses
crankcase pressure pulses against a diaphram in the carb to pump fuel from the
tank. The extra hose you mentioned is simply a return line.

>
>There is a metal "thing" on the side of the heli. Two thick wires go
>into it. It almost looks like a heat sink or some sort of ground.
>Any ideas?

That's part of the ignition system. I'm afraid I don't remember is't exact
function. I think they were replacing the stock magnito ignition system with
some form of electronics. The gas engine helicopters I've flown didn't have
this.

>
>What is the best way to start the motor? Do you have to prime it?

Some of the carbs on these engines have a little primer bulb on them. It's a
small soft button that you push repeatedly until it draws fuel up from the
tank. Any extra will return via that second fuel line you mentioned. Does the
engine have an air filter on it? Most I've seen are a simple black box on the
carb and that should have a choke lever included in it. If it does, simply
choke the engine while pulling it through with the pull starter. Once the
engine tries to fire the first time, turn off the choke and it should start in
the next pull or two, assuming everything else is set and working properly.

>
>What is the best oil to use? Ratio? Source?

Any good quality two-stoke racing oil will work. I've been using Bel-Ray H1R
Synthetic 2-stroke racing oil. I got it from a local Yamaha motorcycle dealer.
Any quality 2-stroke oil will work and I've found that motorcycle dealers are
as good a place to find it as any. I like running the mixture around 44:1
although this oil will supposedly work at leaner mixtures. The engine seems
happy and I'm not having plug fouling problems so I'll probably stick with the
44:1 ratio.

>
>What are the 3 set screws on the carb for? Mix? How do you set the
>mix? How do you know if it is rich or lean?

Three screws? If you'd have asked me, I would have thought there were only
two. One should be for full throttle operation and the other for idle mixture.
If you look closely at the carb body, those should be labeled with an "H" and
"L" respectively. The only other screw I can think of would be for idle speed
control. If that's what it is, I'd remove it. I think it's absolutely
critical that you be able to kill the engine from the transmitter and I always
do that through throttle trim. Failing that, there should be an extra wire
lead coming off the back of the engine. This will be an ignition ground wire.
You can rig up an extra servo, operating a switch that will kill the ignition
if needed. I never liked the added complexity of doing that so I just rely on
carb trim to shut things down.

If that third screw is a mixture control of some sort, then you've got a carb
that I'm not familiar with.

>
>How bad is overheating? Does this mean it is too lean?

If it's overheating from an excessive lean condition, there'll be no doubt. As
with glo engines, it's "always" best to err on the rich side. I find gas
engines more difficult to set the mixture because they don't smoke like glo
engines do. You have to learn to listen to the engine in hover and at full
throttle to gauge the mixture correctly. How well the engine transitions from
the low speed to high speed fuel circuits, usually right about the time it
lifts off the ground by my experience, will also tell you a lot about how the
carb is set.

>
>What type of antenae is best? The standard wire? Dean's short
>antenae?
>

I think the Deans' work just fine. You can use the full length if you want to
but it's "absolutely" imperative that the antenna be kept as far from the spark
plug lead and ignition coil as possible. One other thing I'll recommend at
this time is use a PCM radio system. You may have some folks diagree with that
but gasser heli's can put off a lot of stray RF because of their ignition
systems and PCM simply handles that better than a straight FM radio.

>What is a good source for gasser fuel tubing and other gasser parts?
>

I've found that any parts store that specializes in small engine works, weed
eaters and such, will have everything you need in the way of fuel tubing, spark
plugs, etc. You can also find this stuff through the local hobby shops but not
all of them carry parts for RC ignition engines unless they've got clientele
that are into the large gas powered fixed wing aircraft. You simply don't see
as many gasser helicopter as we did a few years ago.

>MOST IMPORTANT...does anyone have a manual for the heli or engine that
>they can send me a copy of?
>

Sorry, maybe someone else can help with that part.

>This is a lot to ask...but I am really lost. Starting to regret this
>endevor...
>
>Thanks much!
>

You've got a used machine and you may need to do some work on it before you get
it working to it's full potential. I don't know how long it's been since the
engine has been run. If it's been too long, you might be in for a carb
rebuild. If that's the case, it'll probably be easier to simply replace the
carb. They're pretty simple really and not as expensive as you might think.

On the plus side, once you get it going, you'll have a pretty nice flying bird
that'll be reliable and economical. Gas engines don't burn fuel as fast as glo
engines do and the fuel is $2 / gal instead of $15 to $20 for glo fuel. Also,
you don't have to worry about all that start equipment. At a bare minimum, you
only need to bring the helicopter, transmitter, and fuel can to the RC field.
I would bring the tool box too though! ;-)

Hope this helps!
Good luck & Fly Safe,
Steve R.

[OldSchool]

On 01 Sep 2003 02:54:47 GMT, rhodesst@aol.com (Rhodesst) wrote:

>Hello OldSchool,
>

Thank you very much for the response!

>>Dear sirs,
>>
>>I just got a used gasser (x cell 60) without any manual. It has a
>>Zenoah (sp?) engine and graphite body. I am somewhat familiar with
>>glow heli's (I've been flying them off and on for about 5 years).
>>There are some things on the gasser that I just don't recognize...
>>
>>The gas tank is not pressurized? What is the extra hose for?
>>Overflow?
>
>The carburator on the Zenoah is a pumper carb. You should notice a short piece
>of tubing that runs from the engine crankcase directly to the carb. This uses
>crankcase pressure pulses against a diaphram in the carb to pump fuel from the
>tank. The extra hose you mentioned is simply a return line.

I can't find this hose. I only see one hose going into carb, from the
fuel tank. The other hose comes from the fuel tank and doesn't
connect to anything... Do all Zenoah's have the pumper hose?

>
>>
>>There is a metal "thing" on the side of the heli. Two thick wires go
>>into it. It almost looks like a heat sink or some sort of ground.
>>Any ideas?
>
>That's part of the ignition system. I'm afraid I don't remember is't exact
>function. I think they were replacing the stock magnito ignition system with
>some form of electronics. The gas engine helicopters I've flown didn't have
>this.
>
>>
>>What is the best way to start the motor? Do you have to prime it?
>
>Some of the carbs on these engines have a little primer bulb on them. It's a
>small soft button that you push repeatedly until it draws fuel up from the
>tank. Any extra will return via that second fuel line you mentioned. Does the
>engine have an air filter on it? Most I've seen are a simple black box on the
>carb and that should have a choke lever included in it. If it does, simply
>choke the engine while pulling it through with the pull starter. Once the
>engine tries to fire the first time, turn off the choke and it should start in
>the next pull or two, assuming everything else is set and working properly.
>
>>
>>What is the best oil to use? Ratio? Source?
>
>Any good quality two-stoke racing oil will work. I've been using Bel-Ray H1R
>Synthetic 2-stroke racing oil. I got it from a local Yamaha motorcycle dealer.
> Any quality 2-stroke oil will work and I've found that motorcycle dealers are
>as good a place to find it as any. I like running the mixture around 44:1
>although this oil will supposedly work at leaner mixtures. The engine seems
>happy and I'm not having plug fouling problems so I'll probably stick with the
>44:1 ratio.

What happens when the plug fouls? Do you replace it like a glow plug,
or do you clean it, or regap it?

>
>>
>>What are the 3 set screws on the carb for? Mix? How do you set the
>>mix? How do you know if it is rich or lean?
>
>Three screws? If you'd have asked me, I would have thought there were only
>two. One should be for full throttle operation and the other for idle mixture.
> If you look closely at the carb body, those should be labeled with an "H" and
>"L" respectively. The only other screw I can think of would be for idle speed
>control. If that's what it is, I'd remove it. I think it's absolutely
>critical that you be able to kill the engine from the transmitter and I always
>do that through throttle trim. Failing that, there should be an extra wire
>lead coming off the back of the engine. This will be an ignition ground wire.
>You can rig up an extra servo, operating a switch that will kill the ignition
>if needed. I never liked the added complexity of doing that so I just rely on
>carb trim to shut things down.
>
>If that third screw is a mixture control of some sort, then you've got a carb
>that I'm not familiar with.
>
>>
>>How bad is overheating? Does this mean it is too lean?
>
>If it's overheating from an excessive lean condition, there'll be no doubt. As
>with glo engines, it's "always" best to err on the rich side. I find gas
>engines more difficult to set the mixture because they don't smoke like glo
>engines do. You have to learn to listen to the engine in hover and at full
>throttle to gauge the mixture correctly. How well the engine transitions from
>the low speed to high speed fuel circuits, usually right about the time it
>lifts off the ground by my experience, will also tell you a lot about how the
>carb is set.
>
>>
>>What type of antenae is best? The standard wire? Dean's short
>>antenae?
>>
>
>I think the Deans' work just fine. You can use the full length if you want to
>but it's "absolutely" imperative that the antenna be kept as far from the spark
>plug lead and ignition coil as possible. One other thing I'll recommend at
>this time is use a PCM radio system. You may have some folks diagree with that
>but gasser heli's can put off a lot of stray RF because of their ignition
>systems and PCM simply handles that better than a straight FM radio.
>
>>What is a good source for gasser fuel tubing and other gasser parts?
>>
>
>I've found that any parts store that specializes in small engine works, weed
>eaters and such, will have everything you need in the way of fuel tubing, spark
>plugs, etc. You can also find this stuff through the local hobby shops but not
>all of them carry parts for RC ignition engines unless they've got clientele
>that are into the large gas powered fixed wing aircraft. You simply don't see
>as many gasser helicopter as we did a few years ago.
>
>>MOST IMPORTANT...does anyone have a manual for the heli or engine that
>>they can send me a copy of?
>>
>
>Sorry, maybe someone else can help with that part.
>
>>This is a lot to ask...but I am really lost. Starting to regret this
>>endevor...
>>
>>Thanks much!
>>
>
>You've got a used machine and you may need to do some work on it before you get
>it working to it's full potential. I don't know how long it's been since the
>engine has been run. If it's been too long, you might be in for a carb
>rebuild. If that's the case, it'll probably be easier to simply replace the
>carb. They're pretty simple really and not as expensive as you might think.
>
>On the plus side, once you get it going, you'll have a pretty nice flying bird
>that'll be reliable and economical. Gas engines don't burn fuel as fast as glo
>engines do and the fuel is $2 / gal instead of $15 to $20 for glo fuel. Also,
>you don't have to worry about all that start equipment. At a bare minimum, you
>only need to bring the helicopter, transmitter, and fuel can to the RC field.
>I would bring the tool box too though! ;-)
>
>Hope this helps!
>Good luck & Fly Safe,
>Steve R.

Thanks Steve! Don't suppose you live in Michigan...

[Rhodesst]

Hi OldSchool,

>
>I can't find this hose. I only see one hose going into carb, from the
>fuel tank. The other hose comes from the fuel tank and doesn't
>connect to anything... Do all Zenoah's have the pumper hose?

The gassers I've been working with are Bergen machines. They've got the pumper
hose. Now that I think about it, some of them were directly ported through the
engine casing and into the carb where the carb bolts up to the engine so there
wasn't a seperate hoes.

>What happens when the plug fouls? Do you replace it like a glow plug,
>or do you clean it, or regap it?

If the plug starts fouling, you'll hear the engine start running rough. It
will come on gradually and get worse the longer you push things. You can clean
the plug but I've found that once it's fouled badly, you're better off just
replacing it. I've yet to run a plug long enough to need regaping.

These spark plugs are basically what you have in your average lawn mower. You
can get them at a local auto parts store or Home Depot for about $5. That's
cheaper than some glo plugs I've bought. FWIW, the synthetic 2-stroke
motorcycle racing oils I mentioned before are "very" clean burning. Plug
fouling really isn't an issue the way it used to be. I wouldn't worry about
it.

>
>Thanks Steve! Don't suppose you live in Michigan...

Your Welcome! I'm afraid I'm a ways away from you. I live in Texas!

The person I'd point you toward is Larry Bergen of Bergen RC (269-445-2060) in
Cassopolis, MI. If you don't know, Cassopolis is north and slightly east of
South Bend, IN. on Hwy 60 if I remember correctly. He does a lot of work with
gas powered helicopters, especially doing camera work. Don't worry that you
don't have a Bergen machine. A lot of the parts he sells will work on your
X-Cell and he's a very nice guy to do business with. He can also point you
toward others in the south Michigan area that fly gassers. I know there's a
few around there.

Good luck & Fly Safe,
Steve R.

[Steve Simpson]

> >The carburator on the Zenoah is a pumper carb. You should notice a short piece
> >of tubing that runs from the engine crankcase directly to the carb. This uses
> >crankcase pressure pulses against a diaphram in the carb to pump fuel from the
> >tank. The extra hose you mentioned is simply a return line.
>
> I can't find this hose. I only see one hose going into carb, from the
> fuel tank. The other hose comes from the fuel tank and doesn't
> connect to anything... Do all Zenoah's have the pumper hose?

On my Zenoah, the pulse to operate the carb fuel pump was simply an internal passage which ran
through the phenolic plastic spacer between the head and the carb. There is no separate external
tubing for that purpose.

Incidentally, if your engine develops a bad attitude . . . like cutting out momentarily, suspect
a crack in this spacer. Do not overtighten the carb to spacer bolts as that can crack the
spacer.

The tank needs some way to vent, so you will have a line on the tank that is simply oopen to
atmosphere. Mine is routed down to the bottom of the heli where it just pokes out a half inch or
so.

Look here: http://members.cox.net/simpson34/helipage.htm

The last image shows the fuel tubing.


> >>What is the best way to start the motor? Do you have to prime it?

Mine likes to be pulled with the choke on until it fired, then choke off, one more pull and it
would start right up.

Oh yeah and one more thing . . .Gassers RULE!