rstearman

My Feedback: (185)

I have a new 3W 24 engine that I went to start for the first time today. The engine started but ran rough, as if it was too rich so I leaned out the high needle. The rpms increased but the engine would still not reach peak rpms and ran bad. The next attempt to start the engine it fired up in reverse. The engine was a totally different engine. Silky smooth idle, crisp transition and prop ripping peak. Everything was perfect but in reverse. I noticed that the hall sensor wire sheathing on the engine was green in color, which is different from all my other 3Ws. They all have black wire sheathing. Does the green sheathing on the hall sensor designate that it is for reverse rotation?

I switched out the hall with one from another engine and the engine now runs great (in the right direction). I compared the two sensors and notice that on the under side of the sensor the pickups are in opposite locations. This explains the reverse running.

Tired Old Man

My Feedback: (1)

3w discontinued the 24i four years ago, so you having a new one means it's been stored a loooong time.

I have never seen a green wrap pick up on a 24i or 28i, but that does not mean they didn't make any. The timing determines the direction of rotation, not the sensor. If it was a two magnet installation and the sensor was installed upside down it would trigger on a different magnet, which would cause rough running. Normally an engine timed for reverse rotation won't develop much over half power, and that pretty rough power.

rstearman

My Feedback: (185)

I guess I will need a new sensor, It's an old style three wire

If anyone has one laying around that they no longer need please let me know

Thanks
Rick

Tired Old Man

My Feedback: (1)

Just call Gerhard at Aircraft International.

rstearman

My Feedback: (185)

Thanks the info T.O.M.

It seems a lot of guys have switched out there 3W ignitions with after market ones. I'm hoping to pick up somebodies old one l that they don't need anymore.

Antique

My Feedback: (4)

Good luck, the very early 3W ignitions had no silicone boot inside, just a cardboard like substance and some epoxy like filler...They got carbon tracked inside ...The ignitions quit when the timp got too high...Best to get an RC EXL...

rstearman

My Feedback: (185)

Hi Antique

What if I open up the unit and silicone the all components. Would that solve the problem?

Thanks

rc bugman

My Feedback: (30)

If the sensor is green, it is for reverse rotation.

If the sensor is black, it is for tractor rotation.

I think it is a slick solution for reversing rotation and I like it better than the "new" system of redrilling the hub and moving the magnets. But they did not ask me before changing.


The 24 is a great engine, one of the best 3W has produced.

Hope this helps

Elson

rstearman

My Feedback: (185)

Hi Elson

With your 3w 24s did you experience very many ignition failures? I have read about a lot of failures with the older systems but have not had any failures personally.

Tired Old Man

My Feedback: (1)

I would not replace the ignition with another 3w model. For $60.00 you can install something that is expected to last awhile.

rc bugman

My Feedback: (30)

Pat (TOM), correct me if I am wrong.

With the older pickups which are coils, when the ignition fails, replace it with a DA ignition which uses the same coil/sensor.

To go to Xcell ignitions, the magnet needs to be moved on the older engines which requires redrilling, a hall sensor and the new ignition.

I have had a number of ignitions fail. I have about 30 3w engines in my univ project of various sizes. Usually, the cap fails which is a $25 replacement part from AI. The 3W ignition will fail with time. Cross that bridge when it comes. I have ignitions which are years old and many hours that are still chugging along. On the older style ignitions, I only use 4.8 volts even though the ignition with a blue dot is suppose to be good to 6 volts. Perhaps that is why my ignitions last longer than many reported here on RC universe.

Elson

Tired Old Man

My Feedback: (1)

I believe you to be correct about the coil pick up. A two magnet 3w hub does not have to be re-drilled for an RC Exl sensor but a new bracket has to be installed with very minor modification to the bracket slots. A single magnet 3w hub has to be re-drilled, as does an early Chroma engine hub.

3w ignitions hate a couple of things. Heat and vibration. I don't understand the vibration part because they super pot their boxes, but that possitng helps explain some of the heat issues. Compare to a convection oven....

The latest 3w ignitions provide a more "enegertic" spark at more than 4.8v but none of them really need more than 6v. They do last longer at 4.8v.

All ignitions fail with time but some last A LOT longer than others