fbpx
Login

 

Jump to Forum..

914 not making power

in 912 / 914 Technical Questions 14 years ago
Ok heres my problem:
Ive' got a 914 in a Europa and it wont go past about 3700RPM. It started after I removed and reinstalled the carbs to change out the float bowl gaskets. Ive been over it a dozen times and cant figure out what went wrong. its nice and smooth until about 36-3700rpm then it falls and stumbles, any help would be appreacted!

  • Re: 914 not making power

    by » 14 years ago

    Hi Nathan,

    If it started with the carb, that's where i would start and it sounds like a fuel delivery issue. what ever happened you have limited the carbs from passing more fuel so it runs out as you build the higher rpm. You may have bent the float arms or tweaked something else. I would pull both carbs and go over them inside and out. reset the float arm height, check for a bent float guide pin. If your not sure what to look for have a Rotax IRMT look at them. Did you pull the top of the carb off and get the diaphragm turned?

    Roger Lee
    LSRM-A & Rotax Instructor & Rotax IRC
    Tucson, AZ Ryan Airfield (KRYN)
    520-349-7056 Cell

      
    Report

  • Re: 914 not making power

    by » 14 years ago

    Nathan
    Check the float guide pins aren't out of parallel due to over torqued bowl.
    If the problem is already solved what was it?
    Mike G
      
    Report

  • Re: 914 not making power

    by » 14 years ago

    Hey guys,
    The problem was an over-torqued fuel bowl, the nut that secures the float bowl to the bottom of the carb was too close to the main jet and constricting the fuel flow. When the jet assembly was screwed into this nut and air was being blown through it you could hear and feel the constriction as it was being screwed down. Ive got fuel bowls ordered, in the mean-time ive backed off the torque a bit (but enough that it seals proprtly) and engine running has returned to normal. This has also solved the problem that started this whole mess, being a miss at full (115%) throttle. Thanks for the help and the insperation. ;)
      
    Report

  • Re: 914 not making power

    by » Yesterday

    Hi ; 

    I have a problem with the RPM. Everything works perfectly, but at super high power, the RPM drops to 4400, whereas it should be 5000 ± 300.

    At high power, it's 4700, but at super high power, it drops to 4400. I've already changed the fan, oil filter, air filter, fuel filter, oil, carburetor, and spark plugs. There's no problem with the throttle, but the issue persists. 
    the throttle at idle 3-5 , cruise 55 , high power 100 , super high power 115

      
    Report

  • Re: 914 not making power

    by » Yesterday

    Hi Mohammad

    If this is an old engine installation I would guess you have an air leak in one or more of the small black hoses that connect the airbox to the boost valve on the airbox.  At 108% throttle position the TCU switches where you get air to the float bowls and with that switch it runs richer to accommodate take off power.  An air leak will cause a big drop in power since the bowl will not pressurise correctly for full power.

    Cheers

      
    Report
You do not have permissions to reply to this topic.
Related Topics
Title Category Replies
914 build information 912 / 914 Technical Questions 0
914 build information 912 / 914 Technical Questions 0
Rotax 914 & 912? water pipes 912 / 914 Technical Questions 2
Rotax 914 with electric CS prop 912 / 914 Technical Questions 4
914 first powerup- no TCU caution or warning lights 912 / 914 Technical Questions 1
Follow Us

Safety First!

To receive critical-to-safety information on your ROTAX Engine, please subscribe to
ROTAX-OWNER.COM

Recent Videos

Login