RunningMan

The standoffs are really 5mm x 0.8, real close to 10-32, but a 10-32 will fit a bit loose, could strip the threads when tightened. Found this out making some standoffs and taping for 10-32 and the bolts for original standoffs fit so tight that I knew something was not right.

Steve

VeeAte

Not offended at all steve

I ran the RCGF again today with a Zinger 16x8 I have and I got it up to 7,650rpm peak and backed it down to 7,550rpm. Idle is solid at 2,200rpm. I can idle it lower, but it shakes the airframe a fair bit and at 2,200-2,500rpm its quite smooth. Smoother than I expected an engine of this size to be.

Are those numbers ok for that prop?
The engine is running smoother each time I run it.


Also having hassles with the fuel tank. Ihave pulled it out and pressure tested it twice now and can't get so much as a squeak out of the tank and fittings. Yet when Irun the engine for a few minutes Iget fuel on the outside of the tank inside the fuse. The tank stopper is directly behind the carb about 1.5" away. Iknow the gas engines don't spit fuel like the glow engines while they are running so could this fuel be coming from priming the engine and it spitting or dribbling out of the carb onto the tank this way?

Super08

My Feedback: (2)

It is a little weak for a 16x8 on a 26cc. Hopefully it well pick up some as it breaks in. It should be 8,000 or better say up around 8,400. Run some fuel through it and get it run in and then see how it is doing.

VeeAte

It is one of the older engines and I am told they arent as strong as the newer ones.

Thanks for that Super08. I will keep an eye on it and see how it goes.

Pit-Viper 1

My Feedback: (12)

Are those numbers for the 20cc? If so seems a little low. I was only getting around 8000-8200 rpm with that prop so I went to a 15X8 and got it up to 9000-9200 rpm, engine sounded alot happier.


Shane

Pit-Viper 1

My Feedback: (12)

Oh ok its the 26cc, hmm sounds a little low for that prop. Mine is the 20cc not a 26.


Shane

VeeAte

Yeh I agree. I had another look over the engine setup and I think I might need to make some space for air to get to the carb. There is a hole through the firewall directly behind the carb opening and then about 1.5" away is the fuel tank. I have a couple of fuel lines near there too so am thinking it can't breathe perhaps ?

I figured out where the fuel is coming from too. The stopper in the tank was shredded! It's a Sullivan stopper. I got the gas conversion kit.
Could this have been caused from tightening the screw too much on the stopper? It's broken apart on the part of the stopper that is inside the tank.

Pit-Viper 1

My Feedback: (12)

I have damaged the stoppers from tightening them too tight, especially if it has the metal backside. Plastic ones will usually strip before you get them too tight.

Shane

Mr.FiberOptic

mjohnst3, my plane manual says to use a magnetic ring/RF filter on the servo lead. 2 types are made that i found on horizon hobby.

the ring type by Align 3 for $1.99 also by JR 2 for $8.99 and a snap type made by JR 2 for $15.19

i think the Align ones might be small since 3 are only $1.99???? good deal if they are the same as JR's

Align ring http://www.horizonhobby.com/Products...rodID=AGNR1000

JR ring http://www.horizonhobby.com/Products...ProdID=JRPA029

JR snap style http://www.horizonhobby.com/Products...ProdID=JRPA028

goirish

Another dumb question. (boy, seems like I have lots of them). What are these rings for and where do they go? I have my 26 installed on my 1/4 scale clipped wing cub. About 3 tanks run through it. Idle 2300WOT 7200 18/8 prop.

arobatx

If you feel you MUST use a filter, just go to Radio Shack...save some money.  I would personally find and resolve the interference problem, rather than try to filter it out on its way to my system.

karolh

The so called gas compatable stopper from Sullivan is notorious for quickly breaking down when emersed in gasoline. Always use the tried and provenDubro brown coloured gas stopper for trouble free plumbing.

Karol

Mr.FiberOptic

goirish it goes over your servo wire lead to stop interference. if you setup the throttle linkage correctly you might not need one.

that is just what my manual said to use. by the way ive never tryed one.

arobatx

...also if you have a deteriorating sullivan stopper, and without a very good filterclunk in your tank, you will also very likely have unwanted debris in the internal carb filter screen. I wouldn't wait to find out if you have a problem after knowing your stopper was coming apart. It would be worthwhile to have a quick peak and clean, while you are digging in and fixing things.

stangevil29

My Feedback: (1)

For those that have set up a choke servo on the 26cc, how are you doing it? I understand the throttle arm connection because you can take the carb arm off and place a servo arm on top of it. Since the choke arm is different I cant come up with a idea to connect a servo to it. Thanks in advance.

Stangevil29  

VeeAte

Thanks karolh and arobatx.

The carb screen and inline filter were my next item to inspect. The Sullivan stopper lasted about 4 tanks. Its in about 4 pieces and looks eaten out around where the copper fuel lines went through it.

I will order a dubro stopper. Thanks for the help.

Super08

My Feedback: (2)

Grind off the top of the post with a Dremel tool and the arm will come off. Then you can drill and tap the post and use a servo arm or you can use a nose wheel steering arm. You can also buy arms to go on for a couple of dollars. If you want you can also make an arm out of a sheet of brass and attach it to the existing arm with a 2/56 bolt and nut to extend it. Here are some pics for examples...

Bpar4

My Feedback: (1)

I have the 26cc mounted on a GB Obsession.  2 -3 hrs of flight time.  Picked up two new props at Nall last week.  Prop data is as follows:
Xoar 17x6: 8400/ 1900-1950 (wood laminated)
APC 17x6: 8300/ 1900
APC 18x6w: 7900/1800

AUW (dry) 11-2oz, 160oz tank., Amsoil ~60:1

Wonderful engine.  Still having a bit of trouble on cold start.  It won't draw enough to pop w/ choke.  Hit it w/  the starter and it is fine for the rest of day, hot or cold.  Starts w/ 1 hand flip.  Fill the tank and a way you go.  Very fugal on gas.  Still don't have 2 gallons through it..  Will post pics of the setup.  The prop change did not affect hovering the Obsession.  The APC will sort of climb out???  Very slowly.

Will be looking for another plane.  Bob

OCR99

My Feedback: (3)

I just drilled hole in the arm on there and put on a standard jr servo opens and closes fin.

Rick

Mr.FiberOptic

good idea to just leave the little choke arm instead of removing it.

just drill and tap for 4-40 screws and attach a servo arm to the little choke armjust like with the throttle

OCR99

My Feedback: (3)

I just used the little choke arm and drilled hole bigger and put ball joint right on it.then set end points on raidio
Rick

AJsToyz

If anyone is looking for a plane for a 26cc this might be ok.


http://www.hobbypeople.net/gallery/123765.asp

on sale for 199.99

Mr.FiberOptic

im wondering if a 20cc would work fine also.

AJsToyz

It would probably be fine, just have a little extra power with a 26cc.

Andy

DaddySam

My Feedback: (9)

I'm replying to my own advice here. I have been recommending that folks use the Hayes medium neoprene as a clunk line. I recently found that the Hayes medium neoprene line had broken at the clunk inside the tank, twice! So now I've gone back to yellow Tygon for my clunk lines, and will just replace them yearly. The felt clunks I use will provide plenty of weight to move the line around in thetank,but should stay firm enough that theclunk won't be able to come all the way forward in the tank. The mandated replacement will be part of my annual maintenance.
Sam