3W 106 QS doesn't start!

[asimace]

Hello guys,
a friend of mine has this 3W 106iB2 QS that just doesn't want to start... and we have tried really hard! and the poor Composite-Arf Extra 300 is ready for take-off!
The shop where he bought the engine has now changed his ignition box and we will try again to start it up tomorrow.
The problem is that even with the old ignition box the plugs were actually making the sparks so we are not sure that the problem was a faulty ignition box.

I have attached 3 photos.
#1 shows my friends engine.
#2 is a close-up of the timing sensor.
#3 is a picture of another 3W106 that I found on the web.

Do you notice anything strange in the first 2 pictures?
The ignition timing sensor on my friends engine (look at photo #2) cannot be adjusted because both screws are on the inner limits of the slots of the sensor.
Even if we slightly unscrew the sensor, it just cannot move... no regulation is possible. Is this normal?

Photo #3 shows another 106QS and this sensor seems to be adjustable (the screws apparently are in a different position).
Have you ever seen a 3W engine that has a timing sensor that cannot be adjusted?
Can anyone of you check their 3W 106 QS and see if their timing sensor looks like ours?

Let me know what you think because we are having a hard time here and little assistance...
This seems to be an ignition timing problem (we have checked everything else) and if we still won't be able to start the engine with the new ignition box it'll have to go back to the factory...

Thanks, Mauri

[davelucas]

Hello Mauri ,
Even with your pals engine it should still 'pop' . Have you got petrol in the engine ? Was it an unrun engine ? If not has it been sat on a shelf without a tank connected to it ? If it has the main diaphram in the carb might be dried up .If so the quick cure is take out the main diaphram and drop it in petrol for an hour to soften it up . Put it back in the carb and away you go .
Good luck
Dave UK

[asimace]

	Quote: Originally Posted by davelucas
	Hello Mauri , Even with your pals engine it should still 'pop' . Have you got petrol in the engine ? Was it an unrun engine ? If not has it been sat on a shelf without a tank connected to it ? If it has the main diaphram in the carb might be dried up .If so the quick cure is take out the main diaphram and drop it in petrol for an hour to soften it up . Put it back in the carb and away you go . Good luck Dave UK

Hi Dave...
I decided to write on the forum because we are really frustrated with this engine... I fly a MVVS 58 Prosport, another friend has a DA100 so we have a little experience... we haven't noticed anything wrong in the installation...

I also think the engine should at least pop but it just doesn't want to...

The engine is new and shop ownere told us it had only been started at the factory like all 3W engines...
We have checked the carb and the tillotson seems OK... the pump pulls the fuel to the carb in a couple of flips... also after flipping the engine with the closed choke, when we open the choke we have some fuel dripping out of the carb vent (it is of course upside down).
We have tried closing and opening the needles with no luck.
We have even tried to put a drop of fuel directly in the cylinders to see if the engine at least would finally pop but still nothing.
As I already told you both plugs do spark when we flip the engine so all I can imagine is that the timing isn't right... that's why I was curious to know if other 3W106 owners have the same sort of sensor that cannot be adjusted...

The manual of this engine mentions that the one of the two magnets should be green and the other one red... we have two grey ones.
Now we will try the new ignition and we'll see... I will of course let you know the progress!

Thanks, Mauri
Italy

[Dan767]

Looking at your hub, the dot that's on the left, in picture #1 should be the red dot. The dot on the right is the green one. There is only a very small amount of movement to adjust the timing.

[Dan767]

Another thing to check: it's possible to connect the ribbon cable from the hub sensors to the ignition unit backwards. Be sure that the black wires and red wires line up on the respective plugs.

[Bunky F. Knuckle]

Looks to me like the sensor is too far turned to the RIGHT(from looking above the engine in pic 1). Try loosening the 2 screws there, and from viewing mine, my sensor seems to be in it middle of the engine(if it makes sense.).

The red magnet (North Pole)is the UDP(Upper Dead Point). The green magnet (South Pole)is I believe where you make the timing. Timing should be about 55 degree's before the UDP.

I think that it is highly unlikely that you could plug the sensor lead in butt backwards. The plugs are keyed, so that you cannot goof it.

Also check your carb needles. 1 turn out on the high speed and 1 1/2 turns on the low speed.

If we can help any further, please ASK!!!!! We are here to help!!!

Bunky~

PS- I run a 106 as well. I have the updated ingition as well( like you).

[Bunky F. Knuckle]

Did I forget to mention to check the needles first????

[3D-Seth]

I would throw a starter on it and spin it over fast for several revolutions until it either pops or floods. We had an issue like this and after several revolutions of turning it with a starter, it fired and were able to hand prop it after that. Also check your ignition battery to make sure you are getting full voltage and not a drop in case of bad cell.

[sweetpea]

I have a 106 where the stock low end is not rich enough. It won't even draw fuel. Out 1/2 turn from stock and it starts every time!

[TimDavie]

If you are concerned about the ignition, go to ch ignition's web site and print the timing wheel. attach it to a protractor and pull the plugs out. Most of the 3W's have marks to determine TDC. find out at how many degrees advanced the ignition is trying to start the engine. The instructions are on the CH site. The only thing is, I'm not sure with a 3W ignition where the start timing is supposed to be. I have used CH since I had successive problems with 3W ignitions about 5 years ago.

[3D-Seth]

That thing should pop, backfire or something if your getting any kind of spark. It sounds like it might be a fuel/air problem. When you try to start, did you make sure your throttle servo is holding the butterfly open just a little to get air in? You might have to give it 2 or 3 clicks of throttle to get it to start to ensure enough air is mixing with the fuel. That engine is awesome and you are going to absolutely love it when you finally figure it out!

[DesertHucker]

The new 3w ignition will not activate it self until it detects a set speed or revolution fast enough for starting. I would believe if you have both green magnets the ignition would not arm its self. Mine the colors red and green are very distinctive.

Do you have the 3w LED conected?
Is the battery pluged into the correct plug? there are 3 on 3w ignitions
1 Power
2 LED
3 Tacho

With the led conected you can see the ignition is live. and tell when the ignition is armed.

The other senario i have seen is when the keyway has sheared and the timing could be anywere then.

The small amount of adjustment on the hal sensor should not prevent it from starting.

Do you flip it with choke and ignition on?