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Permalink Reply by Bob Pustell on June 24, 2014 at 12:46pm

I have no Rotax knowledge to offer but I do know that SkyTec makes excellent products. If the SkyTec will fit you are pretty much assured of a wonderful starter.

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Permalink Reply by Ron Johnson on June 24, 2014 at 9:04pm

 forgot to mention I have a 701 which has very little clearance between engine mount and the starter. that's why I'm trying to find out if the new HD starter which is longer will fit within the 701 engine mount. again thanks.Ron J. 

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Permalink Reply by Doug MacDonald on June 26, 2014 at 8:23am

There was a change to the supplied Rotax starter in about 2003, likely to the HD model you are referring to.  To accommodate the new starter, Zenith modified their bed style 701 mount to provide adequate clearance for the new, larger starter.  The modification of the bed style mount created an interference problem with the original 912 exhaust system so Zenith also had to modify the exhaust geometry to clear the lower tubes of the newer style 701 Rotax engine mount.

If you have a pre-modification engine and exhaust, it will not clear the new mount without modifying your exhaust for more clearance.  If you have an old mount and try to install the new larger starter, it will not fit (although there are some instructions about grinding an ear off the back of the starter which might work).  Skytec has a fantastic reputation but I don't know how their starter compares size wise to the original Rotax starter.

Essentially, what you want to do is not a simple upgrade.  If you need some guidance on this issue, I worked with Travis Kobush and Roger Dubert from Zenith when I was modifying my old style exhaust to fit the newer style bed mount.  If I were building again and knew I was going to have the fitment issues I encountered with my plane, I would have just upgraded to the newer "dynafocal" style mount and newer cowl.

I realize none of this information helps much but at least you will better understand what you are dealing with.

Doug M

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Permalink Reply by Ron Johnson on June 26, 2014 at 9:39am

 Hi Doug,

  Thanks so much for the information, not want i wanted to hear, I just called Leading Edge Airfoils and asked them to measure the body of the starter its 1/8 inch to long for what I've got for space. Told me my starting problem may not be the starter but the propeller I have a Warp Drive 3 blade metal leading edge.May have something to do with Mass moment of inertia and to go to Rotax / Owners .com there is something about it in there, so will check it out. Thanks again for your Info. Ron J.  

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