CRRC Pro GF26I

[3Dguy]

What size fuel tubing are you guys using?

[FLZman]

3d, With the kind help of Ray, I have learned alot about fine tuning on this crrc. Let me know what issues (if any) you are still having and lets see if we can make your engine purr. The one I got from Ray is now purring with his help. He knows these engines and truly cares that all of them are running right! Not just a distributor!

Z

[JeffElecRC]

Hi All,

I bought one of these from PRCModel (Ray). I've got it in a ~10 lb Cermark Sukhoi Su-26. Anyway, so far I'm pretty dissappointed with the performance compared to others on this thread. I've got about 4 to 5 hours of flying runtime on it.

The absolute best RPM I can get is 7000rpm running the recommend 17x8 XOAR prop. I started with 25:1 low ash dino-oil, and now using 40:1 Synthetic. I've tried 87 and 91 octane. I've followed the golden-method of tuning walbro carbs and have tried leaning/richening the high end to the point with no improvement.

I'm using the Pitts Wrap Around muffler. Stock spark plug and ignition with Lipo and regulator (tried with 4.8 NIMH too). My fuel lines are the biggest that will fit snugly over the fuel nipples on the carb.

Also, I cannot hand-start the engine. I need to use electric starter which it fires up after a couple revs. The best I can get with a hand-start is a weak burp.

How long does it take to break-in to get the performance like 8000+ rpm?

[FLZman]

Does the engine have any compression? If so, I would look in the carb screen for trash that may be blocking fuel flow. How does the plug look? Have you contacted Ray? he knows these engines and certainly will help make it right.

Z

[JeffElecRC]

FLZman,

The engine feels like it has good compression. Are there any checks I can do to ensure there are no leaks? Soapy water test around gaskets maybe?

I checked and cleaned the spark plug a couple times and it was pretty fouled up with black soot. I was using Amsoil synthetic 40:1 and it was leaving soot deposits on bottom of the plane from the muffler. I'm now trying the oil that came with an Evolution 26GT engine at 40:1. It seems to burn cleaner.

I will pull the carb and check the screens.

And yes I have talked to Ray. If there is no improvement as it breaks-in, he has offered to check it out for me.

[3Dguy]

My high speed needle doesn't respond and the engine leans out when the plane is in a nose-high attitude. Also, according to Ray, the high end rpm is unusually high, but I can't slow it down with the H needle.

[FLZman]

	Quote: Originally Posted by JeffElecRC
	FLZman, The engine feels like it has good compression. Are there any checks I can do to ensure there are no leaks? Soapy water test around gaskets maybe? I checked and cleaned the spark plug a couple times and it was pretty fouled up with black soot. I was using Amsoil synthetic 40:1 and it was leaving soot deposits on bottom of the plane from the muffler. I'm now trying the oil that came with an Evolution 26GT engine at 40:1. It seems to burn cleaner. I will pull the carb and check the screens. And yes I have talked to Ray. If there is no improvement as it breaks-in, he has offered to check it out for me.

I would definitely do two things right off bat:

1) On one side of carb is just one big screw that holds the plate on. Take this plate off and you will see a little screen that the fuel passes through. It will be pretty obvious if there is gunk/junk there when you look at it.

2) If you fouled the plug, I would go ahead and change to a new one instead of cleaning the old one especially if it is the torch plug. A lot of guys have put a NGK in the motor.

You can put soapy water around all the gaskets and turn it over with a starter and see if it bubbles but if you have good compression, I doubt this is cause. Also, if the plug was fouled real bad, there is a chance you have a bunch of carbon on top of piston and top of jug.


Hope this helps

Z

[FLZman]

	Quote: Originally Posted by 3Dguy
	My high speed needle doesn't respond and the engine leans out when the plane is in a nose-high attitude. Also, according to Ray, the high end rpm is unusually high, but I can't slow it down with the H needle.

Man 3d, sure sounds just like what my original motor was doing to the T, the one I got from you know who. That was one that we finally rebuilt carb and it started acting much better but only for short time before one of circlips on connecting rod failed and tore it up. Ray has it now in his ER room.

[3Dguy]

Gotcha. I'm gonna try a different carb from my other 26cc. And, if that don't work, it's going to Canada.

[3Dguy]

I got bored.

[FLZman]

3d, I dont think so but I am not the most qualified walbro guy here, maybe rcign can chime in. Of all the carbs I took apart I never had this piece drop out or come out. If it isnt suppose to, that would certainly allow an air leak which would cause the problems you are having. I will forward the pic to my local walbro guy and see what he says. In meantime, maybe one of the gurus will chime in.

Z

[ken crane]

	Quote: Originally Posted by FLZman
	3d, I dont think so but I am not the most qualified walbro guy here, maybe rcign can chime in. Of all the carbs I took apart I never had this piece drop out or come out. If it isnt suppose to, that would certainly allow an air leak which would cause the problems you are having. I will forward the pic to my local walbro guy and see what he says. In meantime, maybe one of the gurus will chime in. Z

i agree it would cause a fuel pressure delivery issue if it were leaking. mine are pressed tight.on the 50 that is the crank case pressure fitting hole. the 50 cchas a tube from that hole onto the back of the crank body.

[3Dguy]

I replaced the seal thingy and plugged it with JB Weld.

[FLZman]

That may have been it 3d, let us know as soon as you try it. If that did the trick, it may be the problem with my carb that is with ray now.

Z

[JeffElecRC]

I solved my problem by switching to the NGK plug. I gained almost 1000 rpm, and the idle is much lower and smoother. Toss the Torch plugs!

Thanks!