Well folks, it's been quite awhile since I last flew my model 4.
Last day of Feb. 2014 to be exact.
Today, after all these months, it runs like new again.

It all started...............way back in Feb. when, on my last flight, the carbs started over-boarding fuel out the overflow tubes on my 912ULS with 875 hours on the meter. Happy it did not catch fire in flight.

I figured I had a carb acting up so I rebuilt both carbs with kits purchased from our newest forum sponsor, Leading Edge Air Foils. I cleaned as best I could the carbs and installed the "big" rebuild kits that include new needles and diaphragms along with all o-rings and gaskets. You guys know the drill.
The old diaphragms looked like new by the way but what the hey.

After reinstalling the carbs it still ran like crap and flooded both carbs spilling fuel out the same little hoses. Now what?

I considered the age of all my hoses and my motor mount rubber shocks and decided to remove the engine and refresh all hoses and motor mount rubber shocks. Maybe the motor mount is letting it shake too much causing the carbs to flood. Off with the engine. Motor mount rubber shocks ordered from Kitfox Aircraft along with new bushings. New hoses ordered from L.E.A.F. along with more carb parts. Getting to be a large project now. Getting hot by this time in the hangar so I diverted attention away from fixing the model 4 to start building on the Model 7 SS.

About Oct. I refocused on the model 4. Engine back on. New hoses all bright and shiny. Started it up, gas still flooding out of carbs. No improvement what so ever. Likely not the motor mounts at all but nice to have them all new again.

Pulled carbs off again. Shipped off to a dear friend who offered to take a look at them and sonically clean both carbs for me and who also installed new o-rings and gaskets just to make sure I didn't miss something in the rebuild that I did earlier. Much appreciated as they came back to me looking brand new and ship shape.

Installed both carbs and fired up the Rotax. Still shaking the same and flooding out before me and Murle Williams could even get close to syncing the carbs. John McBean explained over the phone how to get a really good mechanical sync done before next start up. I did that. Still ran the same, crappy. Murle did a compression test on all cylinders just in case a valve was stuck or worse. All cylinders checked out like new.

I called Steve Beatty at AirScrew Performance in Glendale,AZ. Our local Rotax guru and discussed the situation. Should have done this back in March. He saved my bacon back in 2007 when my Rotax developed a gearbox problem and would absolutely not run. In fact it broke my prop. it started so hard one time. He shimmed up the gearbox back then and it solved that problem. Can he do it again this time?

I told Steve I suspected the gearbox was out of "spec" again but he was less enthusiastic about that then he was back in 2007. He thought it might be a contributing factor but not the biggest factor. He said he thought it was still a carb problem. I decided to try something I was reluctant to try back in 2007 but figured I had nothing to lose. I took the prop off it and started the engine. It ran very smooth and no fuel flooding. Got to be the gearbox. Hurray. Problem solved. Took the gearbox off and took it to Steve. 3 hours later he called and said it was ready to pick up. Can't beat service like that. He found .014 thousands of shims needed is all. Yikes!!! Not near what the 2007 rebuild took. Maybe it's enough to make it work. Steve was still skeptical but hopeful. I installed the gearbox and fired the engine. It ran, not well as both carbs needed to be synced yet but no gas flooding out of the carbs.
After a few minutes of run time it became quite apparent that something was still off. My egt's were way too low on the right bank of cylinders. I had to hold choke on to keep it running.
Murle said it was likely that the pilot jet had a blockage on the right carb so we removed it and he took it back to his shop overnight and discovered a bit of varnish blocking the pilot jet.

Today we reinstalled the right carb, started up the engine and it ran so well I yahoo'ed out loud. Finally it runs like it did 10 months ago. Murle did a slight pneumatic sync as the carbs were almost perfect using John McBeans mechanical sync sequence. I can't wait to get my 3rd class medical scheduled now and get back to flying again.

A huge thank you to Murle Williams, John McBean, Steve Beatty, Phil Laker for all the assistance getting it fixed. It's great to have such talented folks to call on locally and by phone.
Also a big thanks to Phil Laker(Desertfox1), Dan Billingsley (Dan B) and E.T. Holm (Desertfox6) for taking me up to "get some air under my butt" as they say while my Kitfox was down. It sure helps the attitude.

Hope to be posting more flying videos soon also.