Wanting to buy.

[Super Trooper]

Hello everyone. I am new to all this, so I will probably make a few mistakes.
I am looking to buy a KF. So far have bn looking at a model 4 with a 80hp rotax, wide body mod, converted to tricycle gear.
One question I have is, on-going, up keep on the rotax. Is this a big issue as far as having to do constant adjustments?
I also have bn looking at a Series 5 with the 125hp Franklin engine. I have not bn able to come up with much info on the Franklin.
I would be thankful for any help.

[Mnflyer]

Hi welcome to the KF forum this is just my opinion, but the Model 4 with the Rotax would be a better deal. The 9 series Rotax engine is an excellent engine rnot sure I know what you mean by constant adjustments ( are you thinkung of the 2 stroke engine that require carb adjustments with temp changes) the 4 strokes are not like that.
Good luck with your search the Kitfox is an excellent aircraft.

[Super Trooper]

I have heard, and read here, about carb adjustments, vibrations and such. Probably not as much of a issue as I read into it.
Am leaning to the model 4, speedster, since it qualifies as expermental.

[Dorsal]

I have found my 912S to be hassle free so far (200 hrs), I change the oil and balance the carbs (15 min job) about every 25 hrs.

[Super Trooper]

Well, that sounds simple enough. Thanks.

[Wheels]

I have a model four 912 80 horse.
250 hours total time and the plane is a real performer. The engine I have is older by date but only has 281hrs total time and has been a strong runner. There is currently an issue with the new replacement fuel pump offered by rotax but the company is working it out. If the plane has the original pump and checks out with your ROTAX CERTIFIED mechanic, get in. If your mechanic isn't ROTAX CERTIFIED or very experienced with ROTAX, find someone who is.
You will love the money you don't spend on fuel and the speed you get out of that plane.

[kitfox2009]

I have a mid 90`s 912UL (80HP) in my Vixen. I have put almost 200 hrs on it over the last 2years (300TT). I change oil every 50 hrs (Mobil MXT), check carb sync about the same time, never add oil between changes, move the needle valve for winter or summer operation,no oil/coolant leaks. Just a great, strong running engine in my opinion. I fly mostly of pavement (not many bush strips around here) so I am really happy with 1000 ft,/min and 115 ias and about 12 to 15 litres/hour on 87 mogas. It doesn`t get much better than that!
Have fun with it
Don

[rogerh12]

Be sure to consider the rebuild cost as well. For the Rotax 912, it’s not cheap. I have “heard” the parts alone for an overhaul are $8000 and of course, there is labor cost to add in (can someone give an actual cost to do it today?)

[HighWing]

I had 900 hours on my first Model IV with 912UL. I averaged about 100 hours a year which is not a lot, but pretty typical. Some guys fly a bunch and rebuild costs might be more of a factor for them, but 20 years of flying to TBO is not that big a deal. I remember in the old days (with the 1500 hour TBO), Eric Tucker saying he would fly it for 2000 hours and then sell the engine as a core and put another new one on his airplane. For perspecive, 20 years is a third of a typical person's adult life. For the record, I put on the new stator due to the Service bulletin, and changed oil and spark plugs at the recommended intervals. I did rebuild the carburetors at one point but went back to the old needles because the new ones would not seat properly. I think this engine is pretty much bullet proof. Not to say there can't be issues, but someone name any mechanical product that will give 20 years of useful service with only periodic maintenance.
Lowell

[Super Trooper]

The ac I am thinking of buying has around 500 hours. I figure at my age of 60 I will be around 75, give or take a few years by the time a rebuld is a big issue.
I realize that there can be problems with even a new engine, or any product for that matter.
I had developed the idea that these engines needed constant tweeking. Evidently I was wrong. Nothing new about that!
I am waiting on a eaa guy to do a condition inspection and if he says it is airworthy, I guess it will be check writing time. Looking forward to that!
Thanks to everyone for the input, I plan to closely watch this forum for advice!

[DesertFox6]

I wouldn't worry the least bit about the 912, Super Trooper; my prime concern in your situation would be the construction documentation, workmanship quality and current condition of the airframe it's mounted in. If all that meets the approval of your EAA buddy, who, hopefully, is up to speed on the "Foxiness of Kits," you may have found the best of all combinations in an experimental aircraft. No kiddin'.

I finished my Model IV Speedster in 1999 and flew it just days after my 50th birthday. The 80-horse 912 has been in it since 2000 when I replaced the original Rotax two-stroke, courtesy of Desert Fox 3, who was upgrading to the ULS (Thank You Ray!) and I've never looked back. It had 1400+ trouble-free hours on it when some knot-head taxied into me three years ago, bending one of my IVO prop blades 90 degrees backward while destroying his own wooden Sensenich and attached Continental engine! (That'll teach him!)

Our local "Rotax Guru" actually zero-timed the engine upon tear-down inspection; the multi-piece crank was understandably a bit "crankier" than it should have been, and was promptly replaced, but the rest of the engine was otherwise undamaged: Unbelievable! I reinstalled it rather than replace it with the 100-horse. Why? Didn't need the extra ponies, price or fuel burn for the negligible increase in performance that MAY have appeared. That little beast is going to stay right where it is, under my Speedster's cowl, for the rest of its life: Unbelievably tough, dependable, trouble-free and as close to "turn-key" touring as you're going to find in an aircraft engine: That's the heritage of the Rotax 912.

You'll find plenty of support for this opinion of the 912 among the "Kitfox Krowd" on this forum, for sure: Bombardier hasn't sold a zillion of them for no good reason at all, lemme tellya, but there's a deeper, almost "religious" experience that goes with it. :rolleyes:

If you don't believe me, you've obviously never heard Desert Fox 4 recite his "Prayer of the Rotax Tabernacle Choir" over VHF on a Sunday morning patrol of the Desert Fox Squadron enroute to Sedona for breakfast! :D

11 years, 1500+ hours and still purring...

"E.T."
(Franklin? Franklin?? Don't they make stoves?) ;)

[Super Trooper]

Thanks for your imput! From reading this forum, and talking to folks in my area, there is no doubt in my third grade mind that the 912 is the engine to have. As you pointed out, they wold not have sold as many as they have if they were of lesser quailty.
As for my "eaa buddy", I suppose I have to trust someone. Since the ac is 500 miles away I need a set of eyes to look it over and decide it airworthiness before I make the trip to look at the thing.
Since I have never met the guy I trust the eaa program to judge it to be safe. If you, or anyone on this forum, has a better idea please let me know, I am always open to ideas.
My plan is, that if the eaa guy says it is safe and all that, I would make the trip with a trailer and pull it back home and let the local "gurus" look it over for its quailty. I realize it may be a little late to hear bad news at that point, but my plans usually have a few(?) weak parts.
I settled on a kitfox aircraft after talking to a ton of great people that all say kitfox is the way to go. It seems that the rotax gets just about the same respect.
So, again, thanks for your imput, anytime.
Yeah, the Franklin stove I had dealings with was not that good of a stove!

[DesertFox4]

I concur with DesertFox6 on the reliability, durability and performance of the Rotax. It is a great partner for the Kitfox airframe.

[Av8r3400]

The people who have the most time building and flying these airplanes will all agree that today, the Rotax 912 series of engines is the best match for performance, economy and reliability. Tomorrow there may be something else. But, for the 30 year history of this aircraft's lineage, the 912 series has proven itself to be the benchmark.

[dholly]

It certainly isn't my intent to rain on the 912 parade, but take a v-e-r-y close look at the Rotax Letters and Bulletins for that engine if you haven't already. You can plug in the engine s/n on www.rotax-owner.com (http://www.rotax-owner.com) and it will spit back all you need to know. Then pick up the phone and call a qualified Rotax repair shop. Speak directly to a tech who can confirm which actions are considered critical and get an actual estimate of how much that engine will cost to bring up to snuff. You might well be shocked into cardiac arrest after seeing what an early 912 will cost you, here's an estimate from a well-know qualified repair shop for one engine I (briefly) considered buying:


There are a lot of service bulletins and updated required on this engine. Current TBO is 600 hours but can be extended to 1000 hours with updating.


Stator Service Bulletin: Cost to comply $1300

Oil Pump SB: Cost $110

Rocker Arm SB: $2500

Carb socket and carb updating: $450

Oil Tank: $800

Gearbox updating: $500

Labor to R&R engine: $1500

Gasket Set, plugs, filter, etc $2000

IF THIS ENGINE HAS AN ALUMINUM BOX THAT CONTAINS THE IGNITION COILS AND ELECTRONIC BOXES YOU CAN EXPECT TO PAY AN ADDITIONAL 3K FOR UPDATING THAT.

In total you can expect to spend 9k to 13k to update this engine.Other than that, 912ul is a great engine! :)

[DBVZ]

I have heard, and read here, about carb adjustments, vibrations and such. Probably not as much of a issue as I read into it.
Am leaning to the model 4, speedster, since it qualifies as expermental.Did you mean qualifies as LSA? Amateur Build Experimental would apply to the Kitfox 5 too, and it could also be LSA if it had been ALWAYS limited to 1320 gross and NEVER operated with an air adjustable prop. The 5 with the tri-gear is the Vixen, and later models can be converted between either TW or tri-gear. I looked at a Vixen that was 1320 gross in the San Diego area a while ago.

There are other 4-stroke engine options to consider.

Speedster also fits in nearly any garage, at just under 20' with the wings folded.

[DesertFox6]

"...And then there's the Plague..."

Tom Selleck's character, Patrick O'Malley
High Road to China
Warner Bros. 1983 :rolleyes:

[DanB]

Luv it! :cool:

[cap01]

great flick , forgot about it , will have to watch it again .

[Super Trooper]

Okay, I have did a little searching around and it appears that the NOT COMPLIED with for this engine (1993 model) are as follows:

005 Increase TBO
007 ground connection for pickup wiring
015 Replacement of rocker arms
028 Check or replacement of engine suspension frame part #
030 Check for cracks, wear or distortion on carb flange
044 Use of Rotax supplied airbox
052 Installation/use of governors on 912's

Did not find anything about oil pump being replaced or a service about it.

Several Skystar service bulletins NOT complied with.

Any thoughts?
May have to look at the Series 5 with the Franklin. At least it is forty miles from here, thus more easy to check on.

[DesertFox6]

Your list of items isn't exactly an indictment against the engine, Super Trooper, but appears to be a list of items which may or may not apply to any given engine. When Service Bulletins (SBs) are issued they usually come with engine or part serial numbers depending on what's affected. There are several types of "bulletins" that may be issued ranging from FAA Airworthiness Directives (ADs) to Mandatory Alert Service Bulletins (we just had one of those come out concerning crankshafts) and run-of-the-mil service bulletins telling us to look for something or other...just in case. If it doesn't apply to our engine we just "file it away."

A notice allowing an increase in time between overhauls (increase of TBO), for example, isn't anything we have to comply with, rather to take note of and sit back with a tall cool one and rejoice that the manufacturer just told us we don't have to tear our engines apart for another XXX hours! Many other items are "heads-up" alerts to check your own engine for such-and-such because evidence of a possible problem has popped up somewhere in the Rotax world and owners are being advised. The older service bulletins from now-defunct Skystar I can't speak to without reading them.

Without knowing the serial number of the 912 in question or having the engine logbook in front of me, I can't guess at what may be pertinent to that particular engine. You can log into the Rotax company website at Rotax-Owner.com [info@rotax-owner.com] and get a fair-sized education about these engines, their history, maintenance updates and watch instructional videos on care and feeding of same.

Please don't shy away from that engine based on incomplete or inaccurate information; hopefully, your EAA friend can help you with this point or perhaps someone else on this forum who lives near you.
(How 'bout it guys? Can anyone give him a hand here? After the noise from the holidays subsides below a dull roar maybe??)

A bit more information on the 912 is necessary here, so I wouldn't start warming up to that "Franklin stove" quite yet just because it's close by! :D

Hang in there...remember the old "haste/waste adage!

"E.T."

[Super Trooper]

Thanks for the reply Desert Fox 6.
I, kinda, figured that all service bulletins did not effect all aircraft. I have the serial number of the engine,4152396, so I need to check out which apply, if any.
I suppose the thing that bothers me the most is the fact that the ac is located in Tulsa, OK and I am in KY, about 500 miles away. I am depending on the eaa guy there to decide on the condition of the entire ac. I have talked to him several times and plan on more chats with him before he has a chance to do the conditional inspection, which will not be until after the first of the year.
I guess that one of the things that make the kf5 interesting is that it is here in my backyard, so to speak, and I have folks, that I know, that can do inspections and guide me along. But I will say that the kf4 speedster would be my first choice.
Again, thanks for the reply and info!
DRS

[HighWing]

Please consider this as one man's opinion or maybe two men. My used 912UL for my new project is in the serial # range for the mandatory stator exchange as is the serial # of the engine in question. My first one was as well and I did the exchange then. At the time the stator was provided at no cost with free use of the special tools. A neighbor and Model IV owner (1500 hours) and an EAA tech counsler came by to see my project. I told him of my plans to ignore the service bulletin on the stator this time. He agreed with me and reminded me of the original situation that prompted the bulletin. The certified 912 engine in a Katana was routinely rinsed with a strong degreasing solvent and the solvent softened the insulation on one of the ignition wires as it ran through a clamp. The replacement stator had larger Adel type clamps to reduce pressure on the wire bundles. This is my take on the issue. As the builder and maintenance guy, the engine compartment will never reach the point that a solvent will be necessary to clean it up and I can live with the snug clamps. My friend agreed. But, again, take it as two Guy's opinions.
Lowell

[dholly]

Go to http://www.rotax-owner.com > Information > Service Bulletins > By Engine Serial # > Engine Model (Select All Type 912 UL Engines) > Serial # (Enter your engine s/n 4,152.396). The Rotax Document Retrieval System search for that engine returns (26) Service Bulletins, (61) Service Instructions and (16) Service Letters.

Read them. Those considered critical by Rotax are clearly labeled Mandatory. Those considered mandatory by the owners may... and will... vary considerably. Ultimately though it is up to you which is of critical importance, or to what degree compliance or non-compliance is advisable or even desirable.

FWIW, with respect to the stator SB, I too have opted not to replace. In part, due to the background which suggests a very specific set of contributing factors that are not likely to occur in my case (click HERE (http://www.pmaviation.co.uk/admin/upload_pdf/SB98%20Rotax%20912%20stators.pdf)). Also in part due to the considerable time/expense/effort required to comply. That procedure can be seen HERE (http://www.ultralightnews.ca/rotax912/statorupdate/index.htm). Others, like the carb supports and module ground I do consider critical and, thankfully, a relatively quick, easy and inexpensive D.I.Y.

One thing to keep in mind is that several SB's are not necessarily for immediate compliance. While a safety inspection my be mandatory, compliance may be deferred until the next 50hr/100hr scheduled maintenance or (as in the case of the rocker arms) at the next major overhaul interval. Therefore if the engine you're looking at has low hours, it might not require a large cash outlay to bring up to full compliance immediately.

The TBO extension does require the implementation of all relevant SB and SI's (including the stator) and, because the engine may be affected by a previous modification, the SB and SI's have to be carried out in correct sequence and in ascending order. Still, given the considerable cost of overhauling and that used airplane prices depend heavily on remaining time before overhaul, a TBO increase represents a gain in value for all owners. I think it is noteworthy that Rotax not only upped the TBO on the 912 engines, they also made it retroactive.

In any event, forum advice is helpful but I again suggest you speak to a qualified Rotax service repair center for definitive answers. Or search www.RotaxiRMT.com (http://www.RotaxiRMT.com) for a listing of independent Rotax maintenance technicians who can perform service, maintenance and heavy maintenance work or, perhaps, go pre-inspect an engine for you. Good luck!