coopjim

Yes, two plugs per cylinder. I wanted to be sure I got that right.

NGK iridium

NGK iridium

Thought I'd post an update. A lot has happened but not much result. We replaced the plugs and ignition wires, caps and rotors. Adjusted the valves and we sent the carb to Jabiru for inspection. They found the carb float level low and adjusted it as well as cleaning and inspecting the entire carb. We installed it and still had the same power drop at 2500 rpm. The engine is now in a crate headed to Jabiru USA for evaluation and repair. Fingers crossed it's not a big problem. I'll let you all know when it comes back.

What do you mean "dashpot"?

There has been lots written and read about possible cause. We're convinced it's a lean mixture problem too. Run-up is fine. The problem comes with the increase to full throttle for T/O. We've increased carb jet sizes, checked carb float levels, tried running it with carb heat on, partial choke, looked for intake leaks, etc. The Folks at Jabiru USA thought it might be turbulent air in the intake side of the carb so they sent us a device to "stabilize" the air flow. Nothing has worked so far. The Iridium plugs are a new angle and we're happy to try it out. It ran fine last Fall but this problem developed with the colder temperatures. We're about to the point where there are no larger jets that's why the partial interest in the AeroJector TBI. Thanks for the thoughts.

I know this is an older post but I'm curious about this topic since I'm having similar problems. I live in the Midwest USA and we're having a hard winter. I have a Lightning with the Jab 3300 in it. I had an oil pan engine preheater installed and cover the cowl so I have no problems with starting but I'm having a very hard time getting the engine to accelerate to full T/O power after run-up, even using carb heat. We installed larger jets (now running 285 needle and 265 main) but continue to have an almost stalling of the engine when applying full power after run-up. I've asked my mechanic to look into the Iridium plugs. Have they continued to be effective? I'm even considering the AeroJector throttle body fuel injector to replace the Bing. I can't find many folks who have tried it other than in the Sonex. Thanks, Jim

Anyone have experience with the Aerojector (AeroCarb http://www.aeroconversions.com/products/aerocarb/) as a replacement for Bing carby on Jabiru 3300? I don't know that we'll do this but just in case the Bing continues to be difficult to figure out. Still waiting on the "stabilizer" coming from Lightning USA.

We finally reached the Jabiru "experts" here in the USA after the holidays and have done a few things checking things out. Float level was fine. We've now turned our attention toward the air turbulence through the SCAT tube from the air box and are going to install a "stabilizer" at the entrance of the carb, for trial from Jabiru USA. At the same time, we are replacing the small pressure equalizer tube (altitude compensating pressure equalizer) from the air box to be sure it's not part of the problem. For now, we are leaving in the large jets recommended by Bing (265 main jet and 285 needle) to minimize the number of changes. Should have some results in a few days.

Will be discussing suggestions with USA Jabiru and Bing folks this week. Thanks for suggestions and the Service Bulletin.

Gregv, I'm very interested in your lessons learned from this. I have a 2005 Esqual (Lightning) with the Jabiru 3300 in it and have very similar problems. We have been following Bing's suggestions and have been putting in larger and larger main jets. We're now up to a 265 main jet. It is running a little better but still has a loss of power when takeoff power is applied and higher than expected EGTs. We are going to put in a new metering needle from Jabiru USA since the Bing rep says they need replacing every 200-300 hours. Any thoughts?