Texastbird

If that is a Jenn Feng spark plug, then it could be the problem. Its pretty much standard to swap to an NGK plug. Also make sure you have a good hot battery pack.

winterdd

My Feedback: (3)

That was a champion spark plug. The battery was measured at 5.2v under load. I will charge it up n try again.
Thanks

kmeyers

You are of course referring to the plastic sensor bracket. This tells you nothing about the actual position of the hall sensor inside.

Trouble shooting breaks down to:
The ignition
The sensor
The spark plug
The electric power

Sounds like your power and plug are OK.

The ignition should spark everytime the signal wire is grounded. This is the simplest test, I use a paper clip. But, since RCexl sells a tester that runs the ignition from 2000-8000rpm that sells for under 20 bucks there are several availible within our club. If you can find a large local group you might be able to access one.

The sensor I usually swap out a known good one for my test. But for you, I think a bare sensor that is not mounted in a bracket would work well. Even though the plastic bracket is close consider if the IC is not is the correct orientation.inside the bracket. This could yield the results you are getting.

Well this is some more for you to mull over.

winterdd

My Feedback: (3)

Thanks for the info.
I replaced the original crrc sensor with the rcexl sensor. That was a bare sensor clipped on
The plastic mount and I set it a hair line close to the magnet.

The only thing is the polarities. Since the sensor was mounted vertically pointing to the magnet on the hub, which is unlike other engines with the sensor lying flat. So, the hub magnet can meet both sides of the sensors. The fact is, when I rotate the hub back and fort, the ignition sparks on both directions.

Any idea?

kmeyers

Yes, idea one. The sensor (bare IC) works on the side with the two long bevels (this side should have lettering on it. Orientation is important because all other remaining sides have reduced performance. The back side does not work at all.

You say you mounted it vertical pointing at the magnet, this is not correct. You would need to mount it with the large square face with the two beveled sides facing the magnet. this should work best.

You should get a spark everytime the magnet passes and leaves the sensor regardless of direction.

winterdd

My Feedback: (3)

yea. that make sense to me that the sensor picks up signals the best when its lying flat. My other gas engines are like that.
But this 40cc engine original sensor mount comes in vertical. It works fine with the original CRRC ignition. But not with my Rcexl.
However, a lot of ppl switched to Rcexl without a problem. I would just give it a try and switch the polarility of the sensor.

kmeyers

Your video showed missing fires. That means the polarity is right.

winterdd

My Feedback: (3)

When the sensor is pointing to the magnet, I guess the polarity does not matter, since the both sides of the sensor are able pick up the magnet, although, thats not the largest surface.
(oh..., that may not be exactly correct. I remember jediJody mentioned that it has to be in correct polarity for this sensor mount)

um..so what seems to be the problem?
I m going to try a fully charged 6V battery.

Texastbird

Well, that plug is not up all the way in the cap, so it might be too far of a gap for the spark to jump to the top of the plug all the time.

winterdd

My Feedback: (3)

yea, thats a really good point. Thanks
However, I put the spark plug in to show the sparks in the video.
I did tested it without the spark plug and I heard the missing fire inside the boot.

: (

winterdd

My Feedback: (3)

https://www.youtube.com/watch?v=m5d1PWWlmds&feature=youtube_gdata_player I have the stock ignition on it. My tachometer is not working. Does it run right to u guys? Sounds not smooth when idle. Is that normal?

kmeyers

Nothing will ruin an ignition faster then running it without a sparkplug installed in the boot!
Have you read the stickies on newbies to gas?

winterdd

My Feedback: (3)

Yea, Thanks for reminding. Just tried a few clicks without spark plug.

warbird72

My Feedback: (79)

I have aweakened a giant lol.. mine wouldn't fire at all. It had what looked like a pin ***** about 1.5" above the cap!!! That will ruin anyone's day. The engine Will not start. The wire grounds out.

winterdd

My Feedback: (3)

Just read the newbie sticky thread over. On #36 Jedijody suggested some ways to test the ignition without the spark plug in the boot.

dogshome

That's strange. Missing sparks...
Battery is fully charged? (of course!)

Does it run without misfiring?


Getting hot. They need a large amount of running in. Hot as in too hot to touch on the cylinder is not unusual. You should be able to put your finger on the crankcase for a few hundred milliseconds without yelping though! How hot is it?

Oil for running in. ~30:1?

No bogging or reluctance to rev up and a very slight rich misfire at WOT? It is brand new and will need a rich mixture.

You are aware that the RCexcel hall efect sensor detects on the face, not the end?



Just spotted you running vid, it's running lean! Idle is very fast and it should be a lot lower.

winterdd

My Feedback: (3)

1. yea. fully charged battery.
2. Engine won't run with the Rcexl ignition. (it did run once.)
3. With the stock ignition, it runs like in my last vid. I measured the cylinder head temperature with an infrared thermometer, it was at around 220 to 250 F. That was like 15 mins mostly at idle.
4. its running 40:1
5. Both the stock and Rcexl hall sensor has a larger and smaller surface. I just mount the Rcexl the same orientation as the stock one. So, I suppose it detects on the face.
6. I borrowed a Rcexl wired tachometer today. I will try and dial down the idle.
Thanks a lot

winterdd

My Feedback: (3)

Hi,

I'm ready to mount a crrc 40cc on my 27% sbach.
Since this engine uses t shape engine mount instead of standoffs, 2 of the holes will be too close to the top edge of the firewall. See pictures. I'm afraid that would not be strong enough.

Solutions.
1. Extend the top firewall and add reinforcements?
- any suggestions?

2. Just drill another holes on the engine mount below the top holes?

What would u guys suggest?
Thanks a lot

Flight Risk

My Feedback: (1)

I'm not sure that having the holes close to the top edge would be much of a problem. You may need to grind a bit off the side of the blind nuts if you are using those, and reinforce the edge of the firewall.
I would be a bit leary of drilling new holes as they may be weaker if not drilled perfectly, and bending force will be greater as you move to the center. I can't remember why, but I used a set of composite fiber mounts that i had on hand. I guess I thought the metal mounts looked more brittle. Whatever you decide I think will work.

winterdd

My Feedback: (3)

Hi,


I'm looking for a Pitts Muffler for CRRC 40cc engine.
anyone has one for sale?


thank you

jadec241

My Feedback: (29)

Everyone is talking about the ignition on the CRRC 40cc gasser. Anyone know what would cause it to run eratic( it pulsates @ mid to high range). The ignition is a rcexcel 6/7.4 volt setup using the hall sensor from CRRC. Checked timming (28Deg). Tried new carb, checked for leaks, new plug, using a 5 cell 2000 mah nicad battery. We are stumped. Even emailed Milton @ rcexcel. Was thinking it might be the ign. box but am getting good spark.

Scota4570

I assembled one of these a few years ago. It ran with the stock ignition, just not well. Then after a short time it would not run at all. I threw away the ignition and got an RCEXL ignition and sensor. It has run great ever since. The basic problem seems to be that the ignition they send with the kit is junk. I recall that one vendor would upgrade the ignition at the time of purchase for a small fee. If it comes up do that. I am not usre they are even selling these kit engines anymore.

jadec241

My Feedback: (29)

Changed the ignition box, reset timing, carb & anything else I can think of. Fired it up. Seems to run a little better. Have to adj. the carb. it seems to be running a little rich.

Flight Risk

My Feedback: (1)

A couple ideas: A good starting point for carb is low needle, 1-1/3, hi needle, 1-3/4, as jedijody said in post 377 and that seems to be the best setting I can come up with. Also, I needed to solder a tube to the ambient pressure diaphragm cover on the carb, and run tubing behind the engine, as the prop blast was creating problems. Also, you might think of tossing the CRRC hall sensor.

jadec241

My Feedback: (29)

I usually start out with a needle setting of 1 1/2 on both. Yesterday fired it up with a new excel box, got it running & like you said in your post still had to lean out the Hi end. As far as the sensor the mounting bracket on the CRRC is completely different from the Excel sensor mount. I will have to see how to make a bracket for it.