Problem |
Possible solution or link. |
Calculating Redrive RatioIf you have a paramotor for which you don’t know the ratio you can calculate it using one of several methods, measure the radius (or diameter) or count the teeth. Here are the details of each method.
Runup or Static |
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| Grease or oil is dripping out the bottom of the redrive. |
The geared redrive has been over serviced with oil or grease and is leaking past the sealed bearings. |
| Motor revs up but the prop doesn’t go with it. |
1. On clutched units, there may be grease or oil between the clutch shoes and clutch bell. 2. On belt units, there may be extreme slippage of the belt. This is sometimes accompanied by a burnt rubber smell. |
| Motor revs up but the prop doesn’t spin at all. |
This can only happen on clutched units and means that a prop side gear is jammed. A small piece of casing may have broke loose and become jammed in the gears. Separate the case halves and remove the debris. I’ve done this in the field but it took some doing. |
| Prop spins on a clutched unit even at idle. |
1. Engine is idling too high. 2. Clutch spring(s) are broken. This should be fixed right away to prevent other damage to the clutch or clutch bell which can escalate the cost dramatically. 3. Debris in clutch bell. 4. Clutch shoes have artifacts on them. File down any protruding imperfections on the shoes that might be engaging the bell even at low RPM. (courtesy Rick Cavallaro) |
| I hear chirping at idle or a screeching noise when I throttle up. |
1. Belt is loose. Tighten to the manufacturer recommended tension. |
In Flight |
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| Motor revs up but the prop doesn’t go with it. |
On clutched units, there may be grease or oil between the clutch shoes and clutch bell. On belt units, there may be extreme slippage of the belt. This is sometimes accompanied by a burnt rubber smell. |
| Motor dies when I throttle up from idle. |
If it dies suddenly then it may be that the carburetor needs adjustment. There’s a Reed Valve Problem There’s a problem related to the motor’s torquing. In one case, above about 50% power, the motor torqued enough to touch the kill wire on |
| Motor accelerates slowly when I throttle up from idle. | |
Parts |
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| Redrive Parts for the Aerocorsair Black Devil 172 |
Redrive Bearings are as follows. You want the shielded or “sealed” variety.
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