Engine upgrades for the IV

[CaptBeach]

Looking for a KF-V bit seeing a lot more IV's on the market. Not how sure I trust even a low hour older 2 stroke and am enamoured by the idea of Higher performing STOL.

Could a IV be upgraded to the more modern higher HP engines...something like the 915is or the Aeromomentum AM15 at 115 or 140hp?

Thanks for entertaining a newbies questions.

[napierm]

A lightly built KF 4 with a 912uls is a FUN airplane. Just saying.

[littlecricket]

IV 912 with a big bore and a Luga prop is a rocket!

[Av8r3400]

I IV with an 80 hp 912UL and cheap 68" Warp Drive is an incredible performing airplane. A standard 100 hp ULS or low compression big bore (like mine) is a rocket ship.

Turbo and fuel injected engines are just an excessive amount of weight on the nose of a IV, IMO.

[CaptBeach]

I think the general belief is the lighter IV with 912 at 80-100 is a fine ship. But correct me if I am wrong but TBO on a Rotax, big bore kits and high performance Rotaxs can get pricey.

Wondering how one of the 115HP AM15 engines would fair. $14.5k 1500 TBO and AM says $2500 for TBO.

That's got to be a lot of performance for the $$$

[bumsteer]

Maybe. Only one Kitfox that I know of ( Nate Ashton) using the Aeromomentum engine. So you'll be dealing with Aeromomentum for engine mount and support since it"s not supported by Kitfox (at least as far as I know). It may very well be an excellent choice. Just be sure and do your research before jumping in.

Rick

[Av8r3400]

I think the general belief is the lighter IV with 912 at 80-100 is a fine ship. But correct me if I am wrong but TBO on a Rotax, big bore kits and high performance Rotaxs can get pricey.


If you want an airplane that you can insure or re-sell in the future, they aren't so pricey. If you are repowering a IV with a 912, start with a decent used 912 and don't worry about it. I know of several (1200 TBO) 912 engines with over 3000 hours on them. These are not like the antique Lyco-Conti-saurus dinosaur engines.

[jmodguy]

If you want an airplane that you can insure or re-sell in the future, they aren't so pricey. If you are repowering a IV with a 912, start with a decent used 912 and don't worry about it. I know of several (1200 TBO) 912 engines with over 3000 hours on them. These are not like the antique Lyco-Conti-saurus dinosaur engines.

A buddy of mine had a Seminole with 3800 hrs on left engine. Wasn’t burning oil and compressions were still in the 70s. Did a field overhaul to sell it to a flight school.
As for the Rotax, there are numerous threads here and elsewhere on the carbs, ignition modules, reduction drive, and fuel pumps.
Any engine, lycosaur or not has its pros and cons.
I will agree however that a IV with a 912 ULS is a load of fun! 😃🛫