yorab
Ensign
- Joined
- Jul 6, 2002
- Messages
- 960
For clarification: this is the Selectric shift, not the hydro-electric. All electromagnetic and no solenoids.
Just finished playing around with a cooling system issue and I took 'er for a ride up the river. I noticed that the forward gear is slipping under heavy load. This only happens on a hard hole shot or when I give it near-full-throttle once planning. No heavy thud or anything, it just seems like it slips into neutral and the rpms go up. If I ease up onto plane, no issue. Once on plane, if I keep it to 3500 rpms or so, no slipping.
I rebuilt the motor and have about 10 hours or so on it. I never noticed this problem before the rebuild or during the 10 hours after the rebuild--until my last test run. The lower unit components all looked good during my rebuild. I have a ton of pictures from my lower unit rebuild if that helps diagnose the issue. Just ask if you want to see pics of something.
Here is what I had time to do last weekend:
1) I looked at the gear oil. Even though it only had about 2 hours on it, it was milky (pic below). I believe that the problem there was a wonky fill screw seal. I changed the oil and then did a test run on the river. Slipped right from the beginning with a hard hole shot.
2) I disconnected the knife connectors and tested the coils. I got 7.9 ohms for one of them and 8.3 ohms for the other. I believe that this is close enough to the spec of 8.0 ohms.
3) I applied 12v from the battery to each of the coil leads, one at a time. When I did, I could hear a slight clicking sound in the lower unit as the electromagnets engaged the springs. I also could spin the prop in one direction freely, but not the other direction for each lead tested. I did notice on one of the tests that I was able to turn the prop clockwise (when looking toward the bow) about 1/8 of a turn before it locked in. Not sure if that means anything.
4) I marked the prop to check for a spun hub. After the first test, the hub seems to have spun just a little bit (pic below). Or, perhaps it spun a lot and coincidently happened to end up very close to the original line.
I did another test run and looked at the lines again:
It seems to me that the hub is slipping slightly, but I don't believe that this is the cause of the perceived gear slipping issue because a hub that slips a few degrees probably would not be very noticeable, and my problem is indeed very noticeable. It's unlikely that the lines ended up so close to the original lines by coincidence after two tests. Regardless, I replaced the prop with another that I had, but I didn't get time to do another test run. I will do that next weekend.
Can anybody determine anything from this information? Are there other procedures that I should follow to trace the problem source?
Just finished playing around with a cooling system issue and I took 'er for a ride up the river. I noticed that the forward gear is slipping under heavy load. This only happens on a hard hole shot or when I give it near-full-throttle once planning. No heavy thud or anything, it just seems like it slips into neutral and the rpms go up. If I ease up onto plane, no issue. Once on plane, if I keep it to 3500 rpms or so, no slipping.
I rebuilt the motor and have about 10 hours or so on it. I never noticed this problem before the rebuild or during the 10 hours after the rebuild--until my last test run. The lower unit components all looked good during my rebuild. I have a ton of pictures from my lower unit rebuild if that helps diagnose the issue. Just ask if you want to see pics of something.
Here is what I had time to do last weekend:
1) I looked at the gear oil. Even though it only had about 2 hours on it, it was milky (pic below). I believe that the problem there was a wonky fill screw seal. I changed the oil and then did a test run on the river. Slipped right from the beginning with a hard hole shot.
2) I disconnected the knife connectors and tested the coils. I got 7.9 ohms for one of them and 8.3 ohms for the other. I believe that this is close enough to the spec of 8.0 ohms.
3) I applied 12v from the battery to each of the coil leads, one at a time. When I did, I could hear a slight clicking sound in the lower unit as the electromagnets engaged the springs. I also could spin the prop in one direction freely, but not the other direction for each lead tested. I did notice on one of the tests that I was able to turn the prop clockwise (when looking toward the bow) about 1/8 of a turn before it locked in. Not sure if that means anything.
4) I marked the prop to check for a spun hub. After the first test, the hub seems to have spun just a little bit (pic below). Or, perhaps it spun a lot and coincidently happened to end up very close to the original line.
I did another test run and looked at the lines again:
It seems to me that the hub is slipping slightly, but I don't believe that this is the cause of the perceived gear slipping issue because a hub that slips a few degrees probably would not be very noticeable, and my problem is indeed very noticeable. It's unlikely that the lines ended up so close to the original lines by coincidence after two tests. Regardless, I replaced the prop with another that I had, but I didn't get time to do another test run. I will do that next weekend.
Can anybody determine anything from this information? Are there other procedures that I should follow to trace the problem source?
