3W 170 WHO'S GOT ONE?????

[Ramz]

Does anybody know what the spark plug gap should be and what is the proper method for verifying that the ignition timing is correct?

[Andrew Bird]

Someone will probably chime in as to how to know where the timing should be - but having just put a CH ignition on mine, I assume the numbers are pretty much the same?

CH recommend timing set between 25-28 degrees Before Top Dead Centre (BTDC). They supply a template (attached photo) which you line up with Top Dead Centre. There is a nick on the back of the prop hub that is at TDC when in line with the centre of the starboard cylinder (pilot) - at least it was on mine.

Anyway - after some fiddling, I got the template lined up with TDC, took the plugs out and put them in the caps and timed the spark.

At the field I then power timed the ignition by running at full throttle and getting a reading on the tach. I then kept moving the sensor by very small amounts, advancing the timing until I achieved peak RPM. I then backed it off 150 - 200 rpm from peak for the health of the motor.

Obviously I shut the engine down each time I moved the sensor.....

[flyingfarmist]

Hey I just put a ch ignition on an old 3w 120 and it runs better than ever.

[Vic3D]

Guys if any of you wants to save a couple bucks on one of these, I'm selling my 3-gallon-old 3W-170 in the swap shop since I can't transport 40% planes.

[reyn3545]

	Quote: Originally Posted by Vic3D
	Guys if any of you wants to save a couple bucks on one of these, I'm selling my 3-gallon-old 3W-170 in the swap shop since I can't transport 40% planes.

Man, that's a deal! I wish I could affford another one! This is definately the strongest motor in its class, and with those mufflers, it sounds like nothing else at the field.... deep, powerful sound. Good luck!

[flying skunks]

I was at Chief today and he is selling the 170 for $1650 ,I thought that that was preaty cheap ..