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Loosing RPM on my 914

  • rhtrudder
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7 years 8 months ago #8 by rhtrudder
Loosing RPM on my 914 was created by rhtrudder
Hello All
Having trouble with my 914. It looses
500 rpm on take off when going through the throttle gate from 100% to 115%
Have tried everything to fix it
Can anyone help
Regards Greg

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7 years 8 months ago #9 by admin
Replied by admin on topic Loosing RPM on my 914
Greg,
May I ask for some more details in order to help you with this issue?

What is your manifold (airbox) pressure at 100% and at 115%?
Do you have fuel pressure or a differential airbox / fuel pressure gauge installed?
Have you connected to the TCU (Turbo Control Unit) and calibrated the throttle position?
What kind of propeller do you have - fixed pitch or constant speed / variable?


Regards,
Rotax Owner

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  • rhtrudder
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7 years 8 months ago #10 by rhtrudder
Replied by rhtrudder on topic Loosing RPM on my 914
Back again
Ithink I may have fixed it. The previous owner overtightend the caby bowls which caused air leaks hence running lean under boost, it took its toll trying to figure it out. Thanks for your interest.
Regards
Greg
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7 years 8 months ago #11 by admin
Replied by admin on topic Loosing RPM on my 914
On a 914 turbo charged engine, incorrect pressure in the carburetor float bowls, caused by improper float bowl sealing (overtorquing included) or leaking reference lines from the carburetors to the airbox / shuttle valve can cause stumbling and hesitation throughout the RPM range.

If your float bowls have been over torqued, they may have been "warped" and are not sealing against the float bowl gaskets. You can gently "lap" the float bowls on fine wet / dry sandpaper placed on a flat surface (glass or machine plate) and some WD40.

If you suspect your float bowls have been over toqued, check to see that the float pins in the bowl (brass pins on which the floats ride up and down) are still parallel to the sides of the float bowl. If the float bowls are warped, the pins can be tilted over and possibly bind the floats against the wall of the float bowl.

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The torque value for the float bowl attachment screw is 48inlb.
The following user(s) said Thank You: lars, rotaxsvs, Wang Shu

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1 week 3 days ago #21787 by Wang Shu
Replied by Wang Shu on topic Loosing RPM on my 914
Same problems occurred with me.
Good answer.
I have changed the bowl , nut and .ring.
Problems solved

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