Gotta Question

[HighWing]

This morning I went up with a friend to a local airport to look at an Allegro 2000 that is for sale. It has a Rotax 912ULS up front. During the look see, the sales guy pointed out an electrical cord with a typical 3 prong electrical plug and explained it was for a pre-heater to warm the ignition modules.prior to starting - recommended by Rotax. I don't ever remember this being recommended or being discussed on any of the email lists or forums in the 20 + years I have been following Kitfox. Anyone's here use a pre-heater specifically to warm the ignition modules to aid in starting a Rotax engine or ever heard of such a recommendation?

[Norm]

I have a friend with a ULS in his Savage cub that will not start without preheating the engine compartment. He has destroyed his spraque clutch from trying to start it when cold. The Rotax tech that works on it suggested just heating the modules to see if it would start easier. Maybe this is a similar thing.
My old UL with the old style ignition is still starting and giving me trouble free operation. No preheating necessary.

[Av8r3400]

I live in cold country and have been around 912 engines for a while.

I have never heard of preheating the ignition modules to aid cold starting.

[Dusty]

Heating the modules is the recommended "fix" we use here to get reluctant engine to start,replacing them is the long term solution.

[av8rps]

My 912ULS in my Highlander is that way. Get the modules to 50 degrees and it starts great. Below 50 degrees, no start without warming them up.

We need guys in the south to swap modules with those of us in the north. Much less expensive than new modules. Problem solved ;)

[Slyfox]

is there some sort of electrical patch we can put on each module, after all they are small, that we can just turn on for a few seconds and heat them babies up then start.

[HighWing]

Thanks for the replies. I had no idea there was a temperature issue with the modules - Live and learn.

[Norm]

Thanks for the replies. I had no idea there was a temperature issue with the modules - Live and learn.

What is interesting Lowell is that many have heard of hints that point to this but you asking the questions got enough responses to confirm an issue. Would be nice to know if it was a certain series of modules that was later corrected.

[HighWing]

What is interesting Lowell is that many have heard of hints that point to this but you asking the questions got enough responses to confirm an issue. Would be nice to know if it was a certain series of modules that was later corrected.

I am really intrigued by the idea. In some ways it seems mystifying. I checked with a close friend who has about 1500 hours in a Model IV behind one of the very early Rotax 912 ULSs. Coincidentally, he had an engine compartment fire last winter from a pre heat incident - the main reason for the question. This is his response.

"It works great, even better with a full moon. LOL"

This guy had a career in aerospace and he is the one that developed the start procedure I use on my UL
Throttle full out
Ignitions off
Choke pull out
Crank 10 seconds or so
Add about a half turn of throttle
Ignitions on
Choke pull out
Crank
It will start on the first compression stroke and run smoothly even after sitting six months.

[kitfox2009]

Hi Lowell
Well this morning I had a chance to test this module heating idea. Temp about 5 C aircraft hangered.
I use the module off,crank for oil pressure with choke on, modules on, choke and start procedure always with a cold engine.
Anyway it did not even try to fire after multiple attempts.
Ran a heat gun through the front air intake for about 5 minutes and and warmed the modules. It fired up first turn. Go figure!!!
1996 912 UL with 750 hours.
Sweet.
Don

[Rodney]

I just love ❤️ this forum. Learn so much here.

Rodney

[av8rps]

MY 912ULS in my Highlander that has the cold start issue is about a 2006 engine.

My 1993 912UL in my Kitfox does not have the issue of needing modules heated, so I believe this is most likely just an issue with a serial number range of 912ULS's.

I love this forum too...

[Av8r3400]

I've got new modules on an old motor in the Mangy. It will be interesting to experiment with this, this winter...

[av8rps]

I doubt the new modules will be like that. From what I have gathered there is only a small group of modules affected. Oh, and if it is sunny outside and you take off the top of cowl to expose them, that alone can heat them up enough to work even at freezing temps. I learned that by mistake, or should I say out of desperation one day on when on skis.

[kitfox2009]

HI all
I bit more followup. Over the past 6 years I have always preheated when the temp's go near and below freezing. FOXK is in an unheated hanger. I throw a old comforter over the cowel and introduce heat from an electric heater either through the front air intake or through the lower air discharge area. The engine always starts immediately after 30 plus minutes of heating.
I was under the impression that the reason for the quick starts was because I heated the engine a bit BUT now I am thinking it was actually because the MODULES got warmed up. The modules are located high on the engine where most of the heat would be. Engine is a UL probably around 1994 to 96 serial number 4153404.
I have always had a hot start issue and now I am wondering if maybe these modules are subject to temp variations at both extremes. Weird
Have fun
Don

[Esser]

Just thinking aloud, could one put an oil pan heat pad on the modules?

[kitfox2009]

Hi Josh
This winter I plan on laying a Battery Blanket over the modules and try that. Could probably just leave in there all the time and plug it in for a bit before startup. Not cold here yet, just inversion morning fog over the lake. Hope it burns off early tomorrow because a few of us "slow guys" (C170`s and a Pacer) plan on going up to Shuswap Lake Estates for lunch. We land right on the golf course. Just have to do a fly over and a small circuit or they will start playing again when you are on final. Not good.
You will have to get that "High Flier" going and come over next summer.
Cheers
Don

[Esser]

Hey Don, it’s looking like a spring first flight so a summer trip is definitely in the cards. I’ll have to test out that turbo charger over the rocks. I have a buddy with a IV in Golden, maybe I’ll meet him on the way and we can both come out. Hell maybe get kitfox Jim and Norm on board and have a little western Canada kitfox meet up.

[Norm]

Hey Don, it’s looking like a spring first flight so a summer trip is definitely in the cards. I’ll have to test out that turbo charger over the rocks. I have a buddy with a IV in Golden, maybe I’ll meet him on the way and we can both come out. Hell maybe get kitfox Jim and Norm on board and have a little western Canada kitfox meet up.
I have been thinking of a Western Canada meet. I am sure KMach and WannaFly would like to join and I got a new KitFoxer into a model IV, he is in South eastern SK. There is also two new Kitfoxes at my field, both Model IVs. One is a 912ULS and the other my Student liked my Kitfox so much he picked on up for himself. Needs some work but should be ready for spring. Of course KitFoxJim is always ready for a flight and his Son is now flying his Model II. Jim's Model II is the plane you see on Wiki if you do a KitFox search.
Getting lots of fun planes and time to have a fun get together.

[kitfox2009]

Hi Guys
Sounds good. I got out there only once this summer. It was tough slugging with all the smoke. Had the follow TCH all the way (both ways) from Delia to Three Valley Gap, then direct to YYF. Stopped at my old airport in Didsbury for fuel. Was at Hanna when the Vimy boys came through with the VW powered Newports on their cross Canada tour. About 20+ knots when they landed. Lost one on takeoff earlier that day in Saskatchewan.
Seems like we are beginning to get a few more KF`s around. Great.
Have fun
Don