My Fuji 50 had been running happily on its magneto ignition for some 2 years, and has proved easy to operate and very reliable having not been touched once mounted in the model.
So when Paul asked me to evaluate the EIS I was loath to touch what was not broken, as I could not see any advantage over the standard magneto set up, Is it any better? Read on all will be revealed.

The EIS system comes complete with a new alloy prop driver, EIS rotor to replace the mag, EIS sensor that replaces the ATM and its bracket and fittings, and the Ignition black box with new plug lead and wiring for connecting to the sensor by a locking plug. Plus all necessary fasteners and easily decipherable Japanese/English instructions, Paul from J.EN says he is going to rewrite them in English shortly [thanks mate] All that is then required is a quality switch/harness and minimum 720mah 4.8v battery pack. I used a std Futaba receiver switch and 1800mah nmh AA reciever pack that was lying about on the bench. A quality switch is important as some of the budget switches available can cause erratic running or total loss of the ignition.

Fitting and mods required

Start by removing everything on the front of the engine eg, prop driver, mag, ATM and its mounting brackets. Now for some light engineering, two of the old ATM mounting bracket mounting holes have to be bored and tapped out to M5 and to a depth of NO MORE THAN 12mm. If you go any deeper you will need a new front crank case. When the new M5 holes are completed attach the plastic sensor, do not over tighten the bolts as the sensor unit is made from plastic and can be easily damaged.

Next job is to fit the EIS rotor, this simply fits onto the keyed shaft where the mag used to go, a Fuji tool is required next as the retaining nut requires torqueing to 300kg.cm.

The final fitting to the engine is the new alloy prop driver, this has to be used as it is modified at the rear, as the EIS rotor is 10mm thinner than the old mag it replaces so the shaft and nut protrude from the front of the rotor and now fit inside the new prop driver.

All that remains is to mount the EIS box connect the plugs, fit the switch/harness and connect the battery simple.

EIS Advantages

First advantage is the weight saving as the old Mag/ATM system weighed 510grms and with the new EIS system weighing in at 355grms complete with battery and switch/harness. This to me meant less weight hanging off the front of the model, and having an option of moving the C of G rearwards by positioning the battery pack back in the fuselage.

Less frontal area allowing for a tighter fitting cowling, the old Mag had a Dia of 84mm with the old ATM protruding out for another 46mm, the EIS rotor Dia measures 51mm with no further width protrusions and once fitted the output shaft length is 10mm shorter.

Less vibration due to the lighter flywheel effect of the rotor, this also improves engine speed pick up, and an improvement across the prop range of 200 RPM as the prop performance figures will show, with slower more reliable idling and a surprise to me the carb had to be leaned out slightly for both slow and high speed running making what was a very fuel efficient engine even more miserly and that just about covers the EIS.

Prop Performance

Prop Performance with Magneto
Size Make Idle Max
18x10 Grupner Profi 1800 7600
18x10 Smart Wood 1800 7600
20x8 Master Classic 1800 7400
20x10 Master Classic 1800 6800

Prop Performance with EIS
Size Make Idle Max
18x10 Grupner Profi 1400 7800
18x10 Smart Wood 1400 7800
20x8 Master Classic 1400 7600
20x10 Master Classic 1400 7000

Summary

When Paul offered me the EIS system to try, I thought what's the point as the Mag works perfect with no problems, but once fitted the improvements become apparent and I was more than happy to leave it in place. It starts just the same a couple of flicks hot or cold, but has a slower more reliable idle, cleaner faster pick up and that very important higher RPM figure, its also even more economical so in my opinion [being a scrooge] well worth the expense. And if you are already a Fuji owner with a mag and do not feel like converting your own engine return it to Just Engines they will be more than happy to do the work for you.

Just Engines Online | Engine Reviews & Comments | Fuji-Imvac Reviews | Fuji-Imvac EIS Conversion Kit Review