Educational discussion
in 912 / 914 Technical Questions
13 years ago
Hi All,
Just food for thought.
I'm posting a fragment from another site that discusses Rotax 912 engine frequently. Here is the first post and then there were many ideas. The bottom line as you will see in the last post is that simple and sometimes multiple maint items can and usually do make your problem. So you need to be a good diagnostition and start at "A" then "B" then "C" your problem solution may be elusive and frustrating.
This post shows the simple things that were corrected to fix the issue, yet other people wanted to bounce all over trying to solve the problem.
Here we go:
I bought my 2006 CTSW 2 years ago. It was a trainer and currently has 1039 hours tt. It has always been a little cranky about starting. It would intermittently simply refuse to start but once it started, it ran like a top. Lately it has gotten more difficult to the point that it won't start at all. Before you ask, yes it is turning over in excess of 250 RPMs. I recently had the carbs rebuilt by Lockwood and as a precaution replaced the fuel pump. I generally use Mogas but have tried Avgas to verify if the fuel was up to snuff. I also changed the spark plugs and they are wet after attempted starting so, I'm confident that the fuel system is not at fault. I've visually inspected the ignition system but can find no fault there (loose wires, bad grounds, etc.). I am based at KZPH (Zephyrhills, Florida) and there is nobody at my airport either knowledgeable enough or willing to help me. I've taken the Rotax training (service and line maintenance) from Dean at Lockwood and last summer I obtained my LSRM-A rating just so I could do my own maintenance.
So...how can I check the ignition system? What is the likelyhood of both modules being bad? How can I check for a spark? Roger, Tad you guys could solve it in a minute but unfortunately you're not here. Short of pulling the wings and trucking it down to Sebring, I'm at a loss.
The finial answer:
... And the winners are. Roger and Tad for their diagnosis of my carb problem. I brought the plane to Tad in Sebring and he correctly assessed the myriad of minor issues that combined to make a large problem. A poorly adjusted choke, too high an idle and too much tension in the cables in combination with unsynchronized carbs were the problems. Tad did a great job and in no time at all, I was flying back home. Thanks Tad. I'll be seeing you again. You've brought the pleasure back to my flying.
Having small issues combining to make one frustrating one is very common. My help to everyone is to follow the maint. prescribed by Rotax schedules and maint work. Make sure who ever does your work is familiar with what they are working on and has been to a Rotax school. It really does save money in the long run. For example: If a part is becoming worn, replacement right then and there may save other parts from excessive wear or an expensive repair. Having a mechanic that knows what they are doing may save you money on the hourly rate. Example: An untrained and inexperienced mechanic may take 2-3 hours to repair something and a trained experienced mechanic may take 1 hour. Finding a worn part in advance of a failure also saves you from expense.
p.s.
Tad Olmsted is a highly qualified Rotax mechanic in Florida and he would be a good pick for a mechanic.
Just food for thought.
I'm posting a fragment from another site that discusses Rotax 912 engine frequently. Here is the first post and then there were many ideas. The bottom line as you will see in the last post is that simple and sometimes multiple maint items can and usually do make your problem. So you need to be a good diagnostition and start at "A" then "B" then "C" your problem solution may be elusive and frustrating.
This post shows the simple things that were corrected to fix the issue, yet other people wanted to bounce all over trying to solve the problem.
Here we go:
I bought my 2006 CTSW 2 years ago. It was a trainer and currently has 1039 hours tt. It has always been a little cranky about starting. It would intermittently simply refuse to start but once it started, it ran like a top. Lately it has gotten more difficult to the point that it won't start at all. Before you ask, yes it is turning over in excess of 250 RPMs. I recently had the carbs rebuilt by Lockwood and as a precaution replaced the fuel pump. I generally use Mogas but have tried Avgas to verify if the fuel was up to snuff. I also changed the spark plugs and they are wet after attempted starting so, I'm confident that the fuel system is not at fault. I've visually inspected the ignition system but can find no fault there (loose wires, bad grounds, etc.). I am based at KZPH (Zephyrhills, Florida) and there is nobody at my airport either knowledgeable enough or willing to help me. I've taken the Rotax training (service and line maintenance) from Dean at Lockwood and last summer I obtained my LSRM-A rating just so I could do my own maintenance.
So...how can I check the ignition system? What is the likelyhood of both modules being bad? How can I check for a spark? Roger, Tad you guys could solve it in a minute but unfortunately you're not here. Short of pulling the wings and trucking it down to Sebring, I'm at a loss.
The finial answer:
... And the winners are. Roger and Tad for their diagnosis of my carb problem. I brought the plane to Tad in Sebring and he correctly assessed the myriad of minor issues that combined to make a large problem. A poorly adjusted choke, too high an idle and too much tension in the cables in combination with unsynchronized carbs were the problems. Tad did a great job and in no time at all, I was flying back home. Thanks Tad. I'll be seeing you again. You've brought the pleasure back to my flying.
Having small issues combining to make one frustrating one is very common. My help to everyone is to follow the maint. prescribed by Rotax schedules and maint work. Make sure who ever does your work is familiar with what they are working on and has been to a Rotax school. It really does save money in the long run. For example: If a part is becoming worn, replacement right then and there may save other parts from excessive wear or an expensive repair. Having a mechanic that knows what they are doing may save you money on the hourly rate. Example: An untrained and inexperienced mechanic may take 2-3 hours to repair something and a trained experienced mechanic may take 1 hour. Finding a worn part in advance of a failure also saves you from expense.
p.s.
Tad Olmsted is a highly qualified Rotax mechanic in Florida and he would be a good pick for a mechanic.
Roger Lee
LSRM-A & Rotax Instructor & Rotax IRC
Tucson, AZ Ryan Airfield (KRYN)
520-349-7056 Cell
