Home Forums Tech Talk Please help choose Rotax Motor Mount

This topic contains 3 replies, has 3 voices, and was last updated by  shaun s noll 4 years, 7 months ago.

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  • #24108

    shaun s noll
    Participant

    New to racing TAG/Rotax and surprised how much chain adjustment is necessary throughout the day along with the expected sprocket changes, etc for different track config.  The current motor mount is just a normal motor mount and thinking something that is easier to adjust would be nice.  Perhaps like:

    http://sharkshifter.com/zc/index.php?main_page=product_info&cPath=218_224&products_id=1456

    2 questions please:

    1 noticed a lot of the rotax motor mounts are offered in 0 degree, 5 degree, 10 degree, etc angles.  Why is this?  Is there any benefit or change to the different angles?

    2. also, I have never seen this before.  Is there any benefit to pushing the rotax motor 1″ higher in the air?

    http://sharkshifter.com/zc/index.php?main_page=product_info&cPath=218_224&products_id=1727

     

    thanks!

  • #24111

    tony zambos
    Participant

    The scope of your decision on which engine mount to use should be based on more than attaching the engine to the frame.  You’ll have to consider the relationship between the coil and seat strut, the clearance between the pipe and the strut plus clearance beteen the pipe and the brake rotor.  Also consider where the pipe will rest in relationship to the rear bumper.  With the first tap in the rear, you DON’T want the pipe damaged or if you have a plastic bumper, you don’t want it to melt.  That’s why the different angled mounts.

    I’m not plugging anyone, but we use an Odenthal two piece 10 degree mount as seen here, http://www.fastech-racing.com/odenthal-engine-mount-prmax-clamps-not-included.html.  Most of adjustments are done with loosening the two butterfly mounts. The bottom plate has slots for the bolts that attach the top plate. This gives a little additonal adjustment.  Once you have the engine mounted, then consider what gears you might be running and then get a chain.  You should be able to find the recommended gearing for you track and class, or ask on the Forum. You might wind up getting a couple of chains of different lengths to accomodate differenent tracks or limitations on the amount of travel you have for the mount.  Guessing that if you’re making five rear sprocket changes in a day, you might be lost and ask a compeditor.

    Maybe there is a need for raising the motor an inch. I can’t think of one. It’s a water cooled engine.

    See that while I was slowly typing, Chris has lent you a hand as well.  Good luck

    LAD Specialties customer / tony kart / rotax / kt100

  • #24242

    shaun s noll
    Participant

    ohhhh…. of course, that makes perfect sense now about the position of the exhaust relative to the bumper.  The way my kart is setup there is plenty of clearance so the coil and seat struts, etc shouldn’t be an issue.

     

    looks like odenthal 10* is the one.

     

    thanks guys!

  • #24110

    Chris Rock
    Participant

    From Acceleration Karting web site:
    Note: 10 Degree is recommended for Rotax , 5 degree is recommended for all others.

    A 0° or 5° mount on a rotax will point the header down at the rear axle and creates clearance issues when mounting the pipe  Also causes the air box/carburetor to be pointed up at an angle. I have used a bunch of different mounts on rotax and have found the Odenthal  EZ Set mount to work well.

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