fbpx
Jump to Forum..

Rotax 618 Rave diaphram removal

in 2 Stroke Technical Questions 12 years ago
I would like to check for carbon buildup, but I am not sure about how to remove the (nut) that holds the piston (36) on the shaft. Is the nut a seperate part, or is it part of the Exhaust Valve Piston (36)? If I unscrew the piston (36) will the exhaust valve (24) fall into the cylinder? There is oil weeping out from between the piston (36)and the bellows (34) so I assume the o-rings (25) might need replacing. I am experiencing rough idle and I believe my carbs are ok. Any information would be appreciated.

  • Re: Rotax 618 Rave diaphram removal

    by » 12 years ago

    Merle,

    Go to www.ultralightnews.ca/rotax618parts/ravevalvemaintenance.htm

    This site gives detailed instructions on how to remove and maintain the RAVE valve

    Bill
      
    Report

  • Re: Rotax 618 Rave diaphram removal

    by » 12 years ago

    I have read that article, however the nut mentioned (41) comes off with the cap and it is a red adjustment screw that limits travel of the valve. The 10mm hex on the piston (36) turns the piston and bellows (34) together. The 10mm hex is not shown in the diagram, so do I remove the spring (37) then unscrew the piston (36) to get to the allen mounting screws? I am still not sure if the valve will slip into the cylinder.
    I am reluctant to take it apart, in fear of damaging something. Thanks for the help. Merle
      
    Report

  • Re: Rotax 618 Rave diaphram removal

    by » 12 years ago

    Merle,

    You can avoid anything falling into the cylinder by running the piston up to top dead center. In that position, the exhaust port is completely blocked by the piston and nothing can fall into the cylinder. anything that falls in the exhaust port can be easily removed with your fingers.

    Bill.
      
    Report

  • Re: Rotax 618 Rave diaphram removal

    by » 12 years ago

    The RAVE valve itself can never fall into the cylinder as the cylinder has machined stops in it. This ensures the valve can never go down enough to contact the piston, whether the RAVE piston is screwesd on or removed. No need to go to TDC.
      
    Report

  • Re: Rotax 618 Rave diaphram removal

    by » 12 years ago

    Thanks for all the information. I have removed the valves, cleaned carbon, replaced o-rings. The article in ultralitenews 618 maint is not exactly correct. The (nut # 41) is part of the cover. After the cover is removed, you remove the spring then unscrew the (36 bellows). Thanks again for the help. Merle
      
    Report
You do not have permissions to reply to this topic.
Related Topics
Title Category Replies
Rotax 912iS Regulator B w/ Grey Connector Parts 0
rotax rick 618 overhaul 2 Stroke Technical Questions 3
Rotax 582 not smooth at all power settings 2 Stroke Technical Questions 3
Rotax 912iS 2 Sport 912iS Technical Questions 5
ROTAX Service Instruction: Introduction of Sodium-Filled Exhaust Valves and New Cylinder Heads for ROTAX® Aircraft Engine Types 912 and 912 i (Series) General Tech Discussion 9

info@rotax-owner.com