DaleB
Well Known Member
Our RV-12 (engine SN 6775234) has an interesting failure.
The engine has the original ignition modules, with an added soft-start module that I'm 99% sure is the Bully Hawk soft-start module. There is no label on it, other than a QA/date code sticker. Per the original builder's instructions, we normally start on the A ignition only and switch on the B side as soon as the engine is running.
When cold, the first start of the day, it will not start on the A ignition. Crank all you want, it won't start. As soon as you turn on the B ignition, it starts right up. Run-up is normal, with both ignitions working fine. After the engine is warmed up, it will start on the A ignition only just fine. A couple weeks ago when it first happened, I started it 8 times in one day normally, after the first balky start.
We found the ground wire to the soft-start box broken off. Great!! That was an easy fix. Unfortunately, fixing it did not change anything at all. I made a test flight last night. The first time I had to turn on the B ignition to get it to start. I let the engine warm up, did a totally normal run-up, and flew a lap around the pattern. Shut down, and it would start on just the A side with no problem.
So, I think we have a bad soft-start module. It looks like this one is no longer made. The Rotax soft-start for this engine is around $1K, and would require a new flywheel and other parts -- I believe that means pulling the engine. Not really on our list of things we'd like to do, frankly.
Anyone have experience with this and/or have any suggestions? Or a Bully Hawk module for sale cheap?
The engine has the original ignition modules, with an added soft-start module that I'm 99% sure is the Bully Hawk soft-start module. There is no label on it, other than a QA/date code sticker. Per the original builder's instructions, we normally start on the A ignition only and switch on the B side as soon as the engine is running.
When cold, the first start of the day, it will not start on the A ignition. Crank all you want, it won't start. As soon as you turn on the B ignition, it starts right up. Run-up is normal, with both ignitions working fine. After the engine is warmed up, it will start on the A ignition only just fine. A couple weeks ago when it first happened, I started it 8 times in one day normally, after the first balky start.
We found the ground wire to the soft-start box broken off. Great!! That was an easy fix. Unfortunately, fixing it did not change anything at all. I made a test flight last night. The first time I had to turn on the B ignition to get it to start. I let the engine warm up, did a totally normal run-up, and flew a lap around the pattern. Shut down, and it would start on just the A side with no problem.
So, I think we have a bad soft-start module. It looks like this one is no longer made. The Rotax soft-start for this engine is around $1K, and would require a new flywheel and other parts -- I believe that means pulling the engine. Not really on our list of things we'd like to do, frankly.
Anyone have experience with this and/or have any suggestions? Or a Bully Hawk module for sale cheap?