in my case i only move the tank ahead and shorten the fuel line, i have to find time to test with the nidle disabled from the engine block.

Hi all, today I did a new gas conversion on a OS BX1 108.
I made all parts myself (solenoid controller and solenoid housing), and the first time I had an issue with the mosfet of the controller like Fxdr.
I bought IRLD110 on AliExpress and all seem defective:
https://a.aliexpress.com/_mMfQg15

So, I replaced the IRLD110 of AliExpress, by a IRLZ44N bought on Amazon with a 2.2kOhm 1/4w resistor and all work fine now.

The BX1 engine is just incredible, it started with some prop flips, and without breaking in it runs very smooth with a good idle and flat solenoid curve, I'm just amazed!!

https://cimg6.ibsrv.net/gimg/www.rcu...0ca5fef56e.jpg
https://cimg7.ibsrv.net/gimg/www.rcu...64c6245be3.jpg
https://cimg8.ibsrv.net/gimg/www.rcu...dba89fabca.jpg

Tomorrow, the maiden flight!

For engines that large, thereduction in fuel cost is mindnumbing... Those things guzzle methanol but only sip gasoline,

Good luck tomorrow, and remember: The FINAL tune still needs to be done in the air. Keep it a touch rich over the entire fuel range. Otther than that it should be no problem!

No ifs and buts, that is ALWAYS the preferrable way. Not always the necessary way, but you 100% can't go wrong with it.

I did a try today and i still have the same tiny bubbles between valve and needle, the pipe are good quality, and bubble appeared when i accelerate even the tank is moving.Is it possible that the carb suction is too important compared to the feed rate from the valve ? (i didn't touch the valve curve for the moment).

The maiden flight was a success! The engine ran very well. Just a little too rich in the first half of the throttle. Bert, when your mixture is good on the ground but rich in flight, how many percent do you typically decrease the curve points? (I know it's different for every engine, but this is to have a general idea)

Impossible to tell how much. Just creep up on it, with small amounts.

But the strange thing is: I have never seen an engine being "spot on" (good mixture) on the ground, but going rich in the air. To the best of my knowledge, they always lean out in flight.
On occasion, especially in fourstrokes, lean and rich are diffiucult to tell apart (in the pre-solenoid days, when I was still grinding carburettors) I had an engine that I was very convinced it was running rich in midrange in flight while running perfect on the ground. Making midrange leaner worsened things. When grinding a carb, you can ony go one way, overshooting, you cannot go back. After installing the solenoid, and the curve allowed me to "go back and forth" it turned out the midrange as I had it due to grinding, was just right on the ground but too lean in the air. It never goes rich in the air.

So I would carefully check if that engine really gets rich in the air, is my advise.

Does it affect how the engine runs? If not, I would simply try it in the air, and stop worrying about something UNTIL it is proven to be a problem.

ok thanks i 'm going to try on a plane now !

Ok, I will try again tomorrow. But sound of the engine is clearly like "four stroke" so for me it's too rich.
But like you said, with the solenoid I can go forward and backward on mixture ratio. So I will try percent per percent in each direction to find the best ratio.

Deleted......posted to wrong thread

In case of doubt: ALWAYS go rich before you go lean. An engine running "perfect" has a fairly small margin on the lean side of "just right".
If the engine is on the lean side of "just right" that margin becomes razor-thin, and once beyond that margin, it will flame-out like hitting the ignition switch (in other words, very little audible warning).
So if you detect a "non-perfect patch" in the curve, first try to determine as precise as possible, at which exact position of the throttle stick this patch occurs, and in case of doubt, set it one or two percent richer, to see whether it improves or deteriorates. That way, the engine won't cut out and you will not have a deadstick landing to deal with.
Only when you have determined that the engine is actually getting too much fuel in that patch, carefully lean it out until it runs just right.
Do NOT try to get the absolute max out of it. Running smooth is what you want: Remember, that patch is somewhere in the middle of your throttle curve, so NOT full power, therefore pointless to extract maximum performance. Smooth and accurately following the throttle is what you are looking for in the throttle range from 5 to 95%.
At idle you want reliability, at full power you want max performance, everywhere else you want smoothness.

Good luck, and remember: start out a touch rich on the entire upper 3/4th of the throttle range. Lean out gradually, point for point.

You'll get there...

Hi Bert!
Today I made good progress.
First, I installed on my Taranis a switch with a potentiometer that allows to add an offset of -10% to +10% on the curve, with an announcement of the offset value. This solution with the limited offset, allows me to find during the flight if the engine is too rich or too lean for each throttle position, and I can adjust it.
I found that my two converted engines (40FP and BX1) are too rich on the first half of the throttle. Now, the running is almost perfect. As you say, in this throttle range, I am just looking for smooth running and not power, and without risk of dead stick.
I am very happy with this fine tuning method.
Now, my next goal is to be able to start the engine by hand. (For now, I just have occasional engine hiccups, but nothing more, it's not the fault of having watched your startup videos many times...)
Thanks again for all your information. I'm thinking of replacing all my electric planes with converted glow/gas engines 😁

Be aware, that this adjustment is 10% of the numerical adjustment range of the curve, NOT 10% of momentaneous fuel delivery.
At full throttle, this adjustment will work well, but the closer to idle you get, the more coarse this adjustment gets. As long as you return the knob to midpoint BEFORE moving the throttle to the next testing point (there is a "tactile click", you can FEEL where midpoint is without taking your eyes off the plane) this method is safe, but especially if this knob is left in a "lean" position, the risk of deadsticks strongly increases.

With regard to the handstarts: that is strictly a matter of priming: As you may have noticed by now, gasoline has a fairly narrow ignitable range. The trick is to get a charge of fuel/air mixture in the cylinder of precisely the correct ratio. Some engines are VERY finicky about that, others much more forgiving.
I have a few that are extremely easy to prime and start, I hav a few that really need a very precise priming procedure, and one or two that categorically refuse any attempt at priming and handstarting.

I would like to wish all of you inventors, expirimenters, makers and fabricators out there a VERY happy 2025!

Keep them beasties flyin', keep them engines purrin'...

Happy New Year to you too Bert!Health first, and incredible glow/gas conversions in second 😁

Thanks, and I will do my best!

Gelukkig Nieuwjaar ! Happy New Year!

The Best of Wishes for a great 2025 to all of my "Conversion Clan" friends. I hope we all get a chance to all get a bunch of flying in in the New Year - preferable pulled around by our favourite propulsion method..

I have a bunch of ideas bouncing around in my skull - hoping some will make it to the "factory floor" and on the stand and in the air for testing..

Can't wait to see what you will come up with, Chris!

Spitzberg climate
 

Hi folks, we're waiting for Spring or summer effect from global warning, or maybe convert a cix for indoor use. Still ice in North of France

We are finally getting nice weather again and it happened rather quick: 2 or 3 days from barely over freezing, to 15~20 deg C (59~68F), so I woke up two engines from their wintersleep.
Due to circmstances nothing to do with the weather, that hibernation period was about 5 months.
A bit of an oil plug in the carb (long standstill, fuel evaporates and oil remains in the needle's orifice and is at times a bit stubborn to wash out with fresh fuel, but I could get both the Boxer and one of the .52s get to show signs of life pretty quickly.
Once running, both ran as if last time used was yesterday, performing like always, and after that first wake-up call, handstartable like always.

I hope you guys all cam through the winter OK, for a new season of engine and flying fun!

Hello Burt and all.. Survived another Canadian winter and Just waiting for Mother Nature to turn the thermostat up.. She is being stingy and tricking the weatherman. They keep promising above freezing temps but it still has been cooler. The days are longer and the sunlight has heat again so it won't be long.

Can't wait to get out Flying - Have the "pump" experiments from last fall to try out once we can get out - Have to prove out if the great running on a simple setup will translate to the same in the Air.

Hope you all wintered OK and hope you get flying soon..

Hello. I am looking for advice from experts to help me with deciding on the conversion of glow to gas on some engines I have. I was able to purchase a N.I.B. O.S. FF-320 Pegasus engine for a really good price and I've been thinking about the possibility of doing a conversion from glow to gas on that engine using either components from MMM or CH Iginitons (Adrian). I was hoping I could get some friendly help about doing this. Thanks.

If your intention is to buy a conversion kit, or have your engine 3rd party converted, I would suggest using Adrian's services.

For complete disclosure, this thread is very specifically NOT intended for those kind of "storebought" conversions.
This thread aims at doing a very cost-effective and potentially much better home made conversion using electronics to solve the carburation issues associated with the use of gasoline, which is a topic on its own.

If you intend to do the conversion as discussed in this thread, I think, due to the current geopolitical situation and resulting issues with shipping, and cost involved, I cannot be of much help, but the US-based users in this thread probably can.