Love the MK4

[skypics 89]

HI;

Haven't been on this forum in a looong while. Just want to catch up.

I have had two Avids. A model B which I destroyed on an difficult High Sierra strip. Bought a MK4 with a Rotax 582 2 weeks later. It has a bit more cabin room.

I saved the Gen 3 Jabiru 2200 from the crash and installed it on the MK4. The prop, mount, spinner and engine were purchased by a man who drove down from Montana to SoCal to pick it up.

I have over 6,000 hours in Avids and have been completely satisfied with this aircraft which makes me wonder why a business could NOT succeed in the sales of this kit.

I have been through 4 Jabiru engines. I have had 4 engine failures in that time. Two were exhaust valve failures, another threw a rod 30 seconds after i fired it up. It had been repaired by a dealer near Fresno. He did replace that engine with a newer one. Finally, my new Gen 4 fragmented at 170 hours and was replaced after 3 months by Jabiru Australia.  

The replacement engine exhibited a very high EGT  on #2 which turned out to be a manufacturing flaw where the induction tube goes into the cylinder. The land that the o ring rests on was much narrower at the 7 o clock position. This caused distortion of the O ring. The O ring is BUNA-N which is only good to 225 F do I replaced it with a Viton O ring that can handle over 400 F. 

Jabiru would not replace the jug so I had to install a thin shim washer on the o ring land to provide a secure placement. The EGT is now much lower, but still higher than the rest.

I run a Whirlwind 66" 2 blade set to give 2880 on climb out from my 533 MSL field. My climb rate solo with 12 gallons fuel is 1200 FPM. With 28 gallons climb is 900 FPM.

I recently flew to Big Bear airport (6750 MSL) and filled it up to the top with 28 gallons. DA was 8900 at take off and I could still climb at 500 FPM only turning 2750 RPM. I leaned out on climb out and got an extra 30 RPM and a climb of 600 FPM. What a fabulous bird!

I do not prefer the Rotax 912 due to the extra complication of gear boxes, spraug clutches and water supply parts. It is heavier and replacement part are way over priced. I can only imaging how my climb rate would improve with 100 HP, but am not willing to change since this engine has gotten me in and out of many Idaho backcountry strips.

I don't expect to be flying much longer as I have just hit the 84 mark on life's journey so I'm hoping this engine will last till I hang up my headset for good.

Fly safe...stay healthy.

John M