Not getting up to speed

[Maverick]

I have a 912 ULS on a KF5 with a 72" IvoProp and cockpit adjustable propeller. I've been told I should run the engine up to 5,800 rpm and set the prop to 5,600 to fly. I tried this and could only get the engine rpms up to 4,800. I've flattened the prop as much as I can. I've read other threads that suggest that this might be a prop length issue. Does anyone have any experience with this problem? What was your solution?

Maverick

[avidflyer]

Never figured out, did you have a medium or ultralight prop? JImChuk

[Maverick]

Problem resolved. It was the electric prop adjuster. The circuit breaker had popped and I didn't see it. It appears that it is a common problem with the IVO cockpit adjustable.

[charosenz]

Problem resolved. It was the electric prop adjuster. The circuit breaker had popped and I didn't see it. It appears that it is a common problem with the IVO cockpit adjustable.

I know a few folks install an amp meter in line with the prop pitch motor to see if the pitch is actually moving. and of course there are write ups of the use of automatic resettable poly fuzes that will trip before the circuit breaker does and it also has an indicator light when it has tripped.

[Eric Page]

There has been a lot of chatter over the years on the AeroElectric-List forum about a current limiter circuit for the IVO IFA prop system. The idea was to actively switch off pitch motor drive and illuminate an LED when the prop reaches its travel limit, instead of popping and resetting a circuit breaker.

To find all the discussions about this project, click this link, type "IVO" in the "Search for Keywords" field, select "AeroElectric-List" from the "Forum" drop-down, then click the "Search" button.

The Matronics forum software is badly disorganized so finding a coherent thread to read is nearly impossible. If you want to cut to the chase, the final product of the AE-List discussion is found here. As of 2018 a fellow named Todd Bartrim up in Canada had several DIY kits (including circuit boards and components) for the IVO prop current limiter project. He may still have one; his email address is in his AE-List forum post at that link.

[Slyfox]

when the rpm stop going up I let go of the switch, this is when I'm 3 miles out, first I back off the rpm to about 4300, activate the switch to flatten, the rpm will go up to about 5200, that's when I let go of the switch. lol been doing that for years. I also check before flight the switch and make sure the prop works before starting the engine. I listen for that. One last thing, when you wire up everything make sure you do not cut the extra wire out, you loop that up and put under the panel, that acts as a resistor of sorts, if you shorten it the circuit breaker will pop real quick. hope this helps.