Date Posted:19:20:08 10/22/09 Thu Author: Geoff Roe Author Host/IP: 87.114.25.176 Subject: Re: Jabiru 2200 Economy Tiuning kit In reply to:
Mick O'Connor
's message, "Jabiru 2200 Economy Tiuning kit" on 11:43:09 10/21/09 Wed
Mick
Do you know what size drill is supplied with the Skycraft economy tuning kit? JSB 018-2 recommends drilling the idle circuit inlet to 1.6mm, and I did this (very slowly and by hand)when I modified my carb. I had to buy a drill bit for this purpose. Could this be the explanation?
I get more and more confused about this subject. I have no idea what size jets Skycraft include in the latest economy kits (and their website is silent on this), but I thought the purpose of JSB 018 (and see here the latest LAA advice on a recent Jab engine failure) was to get everyone back to richer settings, the economy kit having been shown to be a bad idea. I therefore followed JSB 018 to the letter, and increased my NJ from 276 to 290 and my MJ from 220 to 245, exactly as recommended. (My engine is S/N 2062, by the way.) Since I then thought my engine was running too rich in the summer I consulted Don Richter who told me that in Oz they use a 285 NJ all year round to avoid this problem. (I haven't yet made this change but may do so next summer.) Unlike yours, my engine has hydraulic lifters but I somehow doubt if this explains all the apparently conflicting advice.
Sorry if I've confused you further!
Geoff
PS. My engine has always run at low CHTs but my EGTs were close to published limits until I made the change as per JSB 018, following which the richer mixture predictably brought them well below these limits. The engine now has about 250 hours and is running as sweetly as ever.
