Zman39

My Feedback: (6)

Hey all,

I just got my new crrc 26 in my plane and went to start it. Hard to crank so I checked the needles and both were only open about 1/4 turn..ugh. So I checked the manual and put the needles to factory recommendations and the transition isnt good at all. I was hoping someone could give me some ballpark settings that will get me in air. At least the low end as I think I can fine tune the high end once I got a low that works.

Thanks

Z

mrbigg

My Feedback: (21)

Here's a Walbro tuning page. Good info. [link]http://tech.flygsw.org/walbro_tuneup.htm[/link]

RCVFR

My Feedback: (7)

Is there some reason you have not asked the dealer you bought it from? Just curious.

Zman39

My Feedback: (6)

I couldn't get the link to work or maybe they are having server problems. I will try again later, I would like to read on it.

Thanks
Z

pe reivers

try my forum at
http://www.prme.nl/forum/viewtopic.php?t=10

Zippi

My Feedback: (10)

Zman39,

This is how I normally tune a gasser. Open both high and low needles to 2 to 2 1/2 turns. Fire the engine up and let it warm up. Using a tach, run the engine at full throttle and lean (close) the high needle until you get max rpm and then back it off a few hundred rpm. Now move to the low end. With the engine at idle, quickly move the throttle to full throttle. The engine may sound ok but lean the low end 1/16" and quickly move the throttle to full again and repeat this until the engine hesitates in the transition from idle to full throttle and then back it off (rich) a few hundred rpm. Now move back to the high end and repeat the process first mentioned.

Zman39

My Feedback: (6)

Thanks guys,

Information much appreciated and will be put to use.

One other question. This engine came with a "Torch CMR7H" plug. Never heard of torch, I have always used NGK's in my 50's. Would putting a NGK in it be wise move? I imagine it has nothing to do with the tuning but not sure if this torch plug is of quality or not?

Thanks
Z

pe reivers

Because idle needle is active all the time, and H-needle only at power settings, it is better to set the idle needle first, because at idle, ONLY the idle needle is active. Then after a few flights, adjust both needles to get the midrange right. Midrange has secondary importance, and is very much prop depending. Larger props are easier to tune for perferc midrange, because they load the engine better. Smaller props will have a snot-nosed midrange. (missing beats because of light loads)

Planeclothes

My Feedback: (1)

Z, you say you just put your new engine in your plane. What exactly do you mean by that? How was the engine running before you put it in your plane?

Zman39

My Feedback: (6)

The engine came to me new in box. I mounted engine in plane. I then proceeded to run engine and then posted here. Not sure if that is what you are asking but hopefully answered your ....question?

Zman39

My Feedback: (6)

took the plane and motor to field with directions from PE's website. Understood the process and went on to attempt to tune this one in or at least get it reliable. To make a long tuning story short, there must be a problem on bottom end. Everytime I go to advance throttle, unless I do it REAL slow, the engine acts like it is starving and wants to quit. This indicated to me a lean condition. So I kept backing out 1/8 turn at a time and it never really seemed to make a difference. I think I ended up at about THREE turns out and it was still doing same thing. If I moved stick slowly, it would seem to get past the bad spot and the high end sounds good.
My only idea at this point is to pull top plate off carb and look for trash but I am open to suggestions!!!!

Thanks
Z

Planeclothes

My Feedback: (1)

The reason I asked is because I thought your engine had had some break-in time on a test stand. I don't know what kind of mix, prop, etc. you are using but I can tell you my crrc 26 has only been run for about 2 hours on a home made engine test stand and at first it took about 80 flips to get it started. Second and third starts also took a lot of flips. Then I realized I was going a little over board with priming and the engine was getting flooded. After that, the next couple of times only took a few flips. I am using a 25:1 mix of high octane/standard 2 cycle oil. Prop is a 16/8 wood Zinger and a 4.8v battery pack. My engine seems to transition very well from low to high even though most of the running has been from 2000 to 3500 rpm with short full throttle bursts. The only adjustment I've made so far is a very slight leaning of the high needle, everything else is still stock. Maybe it will help to know what kind of gas mix, prop and battery you are using.

2robinhood

I have a CRRC Pro 26cc.
CRRC Pro pitts muffler for the 26cc.
I am @ 3 - 3 1/2 gallons of fuel through it.
I run 89 octane, with a ratio of 40:1 Penzsoil aircooled.
Low needle is @ 1 1/8 turns out.
High needle is @ 1 3/8 turns out.
I am less then a 100 feet above sea level.
I am turning 9400 - 9500 rpm with an APC 17 X 6

http://www.youtube.com/watch?v=8IQpg_DxpX4

thatairplaneguy

My Feedback: (50)

I have this same engine

About a gallon of 92octane with lawnboy 2stroke oil @ 32:1 mix

I was ruining a 17/6 falcon but chipped its tips to I threw on an apc 16-6. For a flight.

It has always ran well but for the last few flights its started running badly. Nothing has changed and its been on both props.

For the first half tank of fuel into a flight it runs fine. Haven't touched the needles out of the box. Its a bit rich on top and bottom but idles very low and reliable. Transition had a bit of a stumble but it clears out quickly.

But after the first half tank (4-5min of flight time) it starts to run a bit erratic. It will idle lower, so low it will die if not trimmed up a couple clicks. Top end full throttle has a little burble. It will run just sweet at midrange though.
And yet transition becomes awfull. Very stumbly.

Is it time to change plugs or time to start leaning it out? Or does it should like it has leaned itself out?

Texastbird

Plane guy do you have an NGK plug in it? On my CRRC 40, I was chasing the needles somewhat as the engine broke in and started to make a little more power and have less blowback because of the hard ring. It took a long time before I could get a decent transition from low to high. There always seemed to be a "flat" spot somewhere in the rpm range on my engine.

oldbassard

I just bought a Bowman Ring formy RCGF 26. When Mr Bowman sent the ring to me he also inculded anote that said the Reed Valve in these Chinese engines and he did say all of them. Sometime comes with mold flashing that needs clean up.. You remove the plastic reed valve and you can see where the plastic mold marks need sanded to achieve a good seal. It doesn't happen on all of them, but a good idea to check them all, it does happen to often and it lets them suck air between the gasket andthe reed valve

thatairplaneguy

My Feedback: (50)

Anyone have a pic of that reed valve? I have no idea what it would look like or where it would be.

kmeyers

You don't need a picture of the reed block if you have a piston ported engine, because they don't have any reeds.

oldbassard

You can go to engine site and look at replacement parts for the engine, it's the plastic piece that's between the carbureator and the head. The caubretator attaches to the reed valve