'69 185-srv slips out of gear at high rpms

[LaurelG9]

A quick question before I go back up to the mechanic. I have a 1969 185-srv, new to me this summer. We've had some work done on it, most notably replacing the throttle cables. Had it out on the lake this weekend, and with the throttle full-forward, it was slipping out of gear...no forward thrust, but lots of revving. We had it out two weeks ago and it ran fine -- no problems.

Could this be a problem with the cable, or is it pretty common to have to adjust a new throttle cable after an hour or two of running time?

Thanks,

Laurel
Marblehead, Lake Erie, Ohio
1969 185-srv

 

[KRB64]

You didn't spin the hub on the prop did you?

 

[dr.j]

Laurel,
If you are able to look down behind the engine to the lower unit input shaft where it slides into the coupler and it is not spinning, the coupler is gone. The input shaft must turn with the rpm of the engine and runs the water pump if you have an alpha drive. The lower unit gear cluster controls F N and Reverse which moves on a rod controlled by the shifter cable.

 

[Cap10Pat]

I think this 69 boat had a couple of decades before the Alpha drive would be invented!

Because the description says "was slipping out of gear" I'm thinking it was able to be put back into gear and then had the same problem again. A clear description of this would have been nice. So, I don't think something serious broke, and I'm voting for the propeller. I'm curious if this is the old style rubber prop hub? Maybe an old prop.

 

[LaurelG9]

Thanks so much for the replies thus far.

Here's what happened. When I bought the boat, it needed a new prop and a new throttle cable. I had both done with a mechanic that came highly recommended from many people, and the mechanic said the boat looked good, otherwise, esp. for a 1969. I put it in the water the first time, and it ran great, until we came back into port and then it stalled. My husband checked the idle speed, and we set the idle a little higher (about 750 rpms) and the "just barely forward" rpm speed is actually at about 950 rpms.

The second time I took it out, there seemed to be the TINIEST bit of drag. Not anything I could identify, but it felt "different." Then, when we got out on the lake, out of the harbor, my husband was driving, and he pushed the throttle forward, and right before it hit the full-forward, at just about 2500 rpms, we lost our forward forward thrust, very suddenly, but the engine kept revving. When we pull the throttle back, when it hits the same place (about 2200 - 2500 rpms), it kicks back into forward. This behavior has been consistent since then. we've examined the prop best we can, with it still in the water. We're not sure what else to look at.

It's going to be a couple weeks before we can get back to the boat, on the water, and I'm guessing we'll talk to the mechanic before then. But we're both wondering what it might be, and whether it could be related to the replaced throttle cable, or if it might be related to the new prop.

Thanks,

Laurel
Marblehead, Lake Erie, Ohio
1969 185-srv

 

[KRB64]

That's weird. Is there a bang or grinding sound when it happens? Or when you pull the throttle back and it re-engages?

Swapping props will narrow it down. Next I'd be checking for metal fillings in the lower unit oil just in case...

Since the mechanic installed the prop and cable I'd definately check with him first.

Good luck.

 

[SR Tech]

If you are getting throttle before your shift engages, then you need a shift cable adjustment or even a new Intermediate shift cable(from the linkage to the drive.)