I have asked Adrian from CH-Ignition for a ignition set for a FA-100 (I intend to use glow fuel). He asked for some dimensions, and if the FA-100 has similar dimensions to the FA-91. Below is the dimensions which I measured. I wondered if anyone can confirm them in case I screwed up.

Prop Hub length - 1.20cm
Prop Hub Dia. at the bearing - 2.78cm
Prop Hub Dia. at the prop - 2.78cm
Distance between the bolts on the Cam Gear Housing - 1.5cm

Thanks for any input.

Originally Posted by rmsingh

I have asked Adrian from CH-Ignition for a ignition set for a FA-100 (I intend to use glow fuel). He asked for some dimensions, and if the FA-100 has similar dimensions to the FA-91. Below is the dimensions which I measured. I wondered if anyone can confirm them in case I screwed up.

Prop Hub length - 1.20cm
Prop Hub Dia. at the bearing - 2.78cm
Prop Hub Dia. at the prop - 2.78cm
Distance between the bolts on the Cam Gear Housing - 1.5cm

Thanks for any input.

The FA100 & FA91 use the same part # for the prop hub. Adrian has the dimensions for that as he made a system for my FA91.

The cam cover is the same part # bas my FA200Ti (FA170R3)
All medium sized Saito singles now use that cam housing. You may have to file the gap wider between the the screws on the hall sensor holder just a little as this is a 2 web housing. Not a big deal. The other alternative is to remove one of the webs on the cam housing. (not a good idea IMO)

Measure the outside width of the 2 webs between the screws of the cam housing & give that data to Adrian. The holes are slotted, the clearance for the housing webs is the most critical dimension here.

My biggest concern would be the distance from the OD of the prop hub to the top edge of the cam housing @ the screw boss. This will determine the OD of the trigger magnet ring.

Make sure Adrian has the dimension from the prop hub OD to the top of the cam housing screw boss.

With these dimensions he should be able to make you a perfect fit.

Prop hub exactly the same as FA91S. (determines ID & length of the magnet ring)

Distance across the outside of the 2 cam housing webs. (determines the ID of the slot between the screw holes)

Distance from the OD of the prop hub to the top of the cam housing screw boss. (determines the OD of the magnet ring)


Your going to love this conversion.

Experiment W/the timing. Run the minimum advance that gives you the maximum RPM. On my FA91S that was 35* BTDC.

200 more RPM than the 28* setting W/the same idle, starting & transition characteristics.

DO NOT BE AFRAID OF MORE AGGESSIVE SPARK ADVANCE TIMING W/METHANOL FUEL
Methanol has a slower burn rate than gasoline & it needs more ignition advance for top performance.

See post #11 in the thread below for improvements W/CDI.

http://www.rcgroups.com/forums/showthread.php?t=1774802

Thanks SR. T, I will forward this info to Adrian.

Ok here are the latest shots. Finally have good weather today and started her up. I'm getting a steady idle at 2200rpm and a top end at 8900rpm using a 15 x 6 prop. But I have a hesitation on rev up.
The timing is set to around 30 - 32deg BTDC.
I'm waiting for my Rcexl tachometer to arrive get more accurate rpm readings.
I have also leaned out the LSN quite a bit but I still get a slight hesitation. Any ideas?

Originally Posted by rmsingh

Ok here are the latest shots. Finally have good weather today and started her up. I'm getting a steady idle at 2200rpm and a top end at 8900rpm using a 15 x 6 prop. But I have a hesitation on rev up.
The timing is set to around 30 - 32deg BTDC.
I'm waiting for my Rcexl tachometer to arrive get more accurate rpm readings.
I have also leaned out the LSN quite a bit but I still get a slight hesitation. Any ideas?

Hesitation on transition indicates that the LSN is rich.

Too lean on the LSN & the engine will die on transition.

Keep leaning the LSN out as long as it doesn't die on transition.

You should be able to get idle down to the 1700-1800 range.

I get 1700 W/my FA91SCDI W/a 15 X 5 Zinger wood prop & get 9700 RPM @ WOT.

It could be that the HSN is too rich & affecting the LSN setting. You should set the HSN 1st.

Lean out the HSN until it sags, open it up until you get max RPM, open it up more untill it sags, then close it back down until you just get max RPM.

Unlike glow ignition, there will be a broad HSN setting where there is no difference in RPM. You want to be on the rich side of that setting, but do not go "300 RPM lower" on the rich side, it is not needed W/CDI. The HSN setting will not affect ignition timing like it does on glow ignition.

Go back & re-visit the LSN setting after you get the HSN optimized.

After you get it running well @ 30°, put a few more degrees of advance into it. 34° to 35° BTC is about optimal for methanol fuel. You will get max power @ 34° to 35° yet idle, starting & general low speed handling will not be degraded.

Thanks I'll give it try.