2 stroke vs 4 stroke questions

[Aviator]

Im looking to buy a used KF 3 or 4 probably, Im just undecided between the 912 and the 2 strokes that they are powered with, Ive only flown planes with 4 strokes, and never rode in a KF yet (but want to if I can find a way).

Curious on your thoughts? the 4 stroke more reliable? Cheaper to run/maintain?

Thanks!

[Monocock]

If you have a choice of a 4 stroke then it is worth considering. However, don't dismiss the 2 strokes as they are great simple engines that you can have loads of fun with. They're not built for cruising but will look after you if you look after them.

My personal choice would be a 912 though.

[Aviator]

anyone had a 2 stroke fail? Buddy of mine wouldnt touch a plane with a 2 stroke, not sure I would either unless I was over fields all the time, but looking for opinions as they are alot cheaper to aquire.

[Aviator]

hows your takeoff roll in your bird with the 912?

[Av8r_Sed]

I'll take a crack at this:

Economy: 2 strokes cost less to purchase and less to overhaul but require overhauls more often. 4 strokes are more fuel efficient which could save 1 to 2 gal/hr in cruise for a Kitfox.

Reliability: The edge would go to the 4 strokes. Once they're dialed in they can be fairly trouble free. 2 strokes require greater knowledge on the part of the operator to keep them within allowable temperature limits in flight. They also require more adjustments as seasons or operating altitudes change.

Power/Weight: The lightest planes use 2 strokes which can give some advantages on very short fields. 4 strokes generally are heavier but can deliver more overall power than the popular 2 strokes and allow for higher cruise speeds.

Judging from what I see on the list, the majority favor the 4 strokes if they fit the budget. 2 strokes shouldn't be overlooked though, because they can get you in the air at the lowest possible cost.

My choice for now is the 2 stroke because I think I can master the learning curve and I don't want to invest an extra $6 to $8K just to get it in the air.

-- Paul S

[Aviator]

Thank you Paul

[Dave F]

Im looking to buy a used KF 3 or 4 probably, Im just undecided between the 912 and the 2 strokes that they are powered with, Ive only flown planes with 4 strokes, and never rode in a KF yet (but want to if I can find a way).

Curious on your thoughts? the 4 stroke more reliable? Cheaper to run/maintain?

Thanks!

I don't think either one is more reliable. The operator/maintainer skillset does have a lot to do with it. I find the tinkerers are the one that have the most troubles. 912 ir a 582 does not matter.

I have thousands of 2 stroke hours and in over 30 year I have have one stop running. ( was a Rotax 185 single ignition on a Lazair in hte Very Early 80s Carbon in gap of plug- landed on one engine pulled plug- clenaed and off again)

You can find 2 sroke Kitfoxs up to Model Iv for 12 to 20k
same one with 912 from 23 to 30 k

Or you can pay double that again for a kit and build it.

Kitfox a great plane, safe and fun.

Check my movies 503, 582 912 and 912S Kitfoxes.

It is what you can afford it seems but build them light to perform.
I have seen 912 Kitfox IV @ 600 lbs and also some tanks at 900 lbs......
unreal !!