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Throttle Shaft Nut Torque

T

Tacco

Well Known Member
Just replaced my throttle return springs. Anyone know where to find the torque value for the throttle shaft nut?
 
Tacco said:
Just replaced my throttle return springs. Anyone know where to find the torque value for the throttle shaft nut?
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I believe it is 44 in/lbs...I did mine nice-and-tightly (used the removal force minus the pull of gravity of the moon+.00003 % weight of plane)��
 
Last edited:
I found 44 in pounds in an older German version of the Rotax Illustrated Parts Catalog. For some reason they deleted the torque values in the latest English version.
 
44 in/lbs confirmed yesterday by my airport Rotax AN&P specialist.

While doing the SB I found that the throttle arm can slide out and in without changing the throttle cable adjustment therefore no carbs rebalancing necessary.
Looks like the new springs are not pulling as much, should result in easier throttle adjustment and no more undesirable slippage.
 
WingedFrog said:
While doing the SB I found that the throttle arm can slide out and in without changing the throttle cable adjustment therefore no carbs rebalancing necessary.
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I can not emphasize enough how much I recommend that other RV-12 owners that do the spring upgrade, not follow this advice.

As has been discussed in other threads (and confirmed by others that have done the spring change), the amount of play in the fit of the arm to the shaft is well beyond the fineness level that we are adjusting when doing a carb. sync.

Flying for extended periods of time with the carbs even just a bit out of sync is the perfect way to spend a bunch of money on gear box repairs.

During carb removal for service/inspection, professional shops remove the arms from carbs all the time to avoid redoing the coarse set-up of the throttle cables but they always redo the carb sync using gauges afterwards.
 
rvbuilder2002 said:
I can not emphasize enough how much I recommend that other RV-12 owners that do the spring upgrade, not follow this advice.

As has been discussed in other threads (and confirmed by others that have done the spring change), the amount of play in the fit of the arm to the shaft is well beyond the fineness level that we are adjusting when doing a carb. sync.

Flying for extended periods of time with the carbs even just a bit out of sync is the perfect way to spend a bunch of money on gear box repairs.

During carb removal for service/inspection, professional shops remove the arms from carbs all the time to avoid redoing the coarse set-up of the throttle cables but they always redo the carb sync using gauges afterwards.
Click to expand...

Thanks for the advice! I will not follow my own advice either :eek: and get a carb sync performed. I did not realize that the little play visible when the throttle is pushed to full was that critical.
 
WingedFrog said:
Thanks for the advice! I will not follow my own advice either :eek: and get a carb sync performed. I did not realize that the little play visible when the throttle is pushed to full was that critical.
Click to expand...

It's not the play in the cable that is the issue.
It is the play in the arm connection to the shaft before tightening the nut. There is no way to know if the arm is returned to exact same position with in that play range.
 
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