prop not turning

gary allen · Posted: Thu Jun 04, 2009 10:43 am Post subject: prop not turning

I'm sure the expertise of this group can give me some clues about where to begin with this problem.

While cruising in Tomales Bay yesterday evening, I suddenly noticed that the prop on my port Honda 50 was not turning. I was backing up out of some shallows when I saw that the tachometer indicated very high rpms but there was no power. I subsequently went back to shore and looked at the prop. There was nothing tangled in it, the cotter pin and nut and washers were still in place, it spins freely, but it is not engaging in either forward or reverse.

I don't know if it could be related, but I had the impellers changed on both motors about a month ago. This was maybe the third time taking the boat out since the replacements, and I had noticed no probems previously.

We had to limp back the ten miles or so to Spud Point Marina in Bodega on the one motor--about 7 knots per hour.

Any ideas? I'd like to try to fix this myself.

Thanks for the help,

Gary

Captains Cat · Posted: Thu Jun 04, 2009 10:56 am Post subject:

Gary, there is a rubber bushing between the outside hub of the prop and the inner splined hole. That is there to cushion things and to "let go" if you hit something so you won't break a drive shaft or worse.

When it lets go, the engine would react as you described. It indicates a "spun" prop as it is called. If you remove the prop, nut/cotter pin and pull it off, it should become obvious.

Not sure if that is repairable or not, probably not.

Btw, does the motor sound like it's going into gear? You can usually feel that in the shift lever. If not, there's a rod that runs from the lower unit up to the power head that has some lock nuts on it. if that has loosend, you can shift without the lower unit engaging. If you had those impellers changed lately, it could have been not tightened by the mechanic.

Here's the picture from the outboards pictures section. You can clearly see the shift rod, the lock nut and the adjusting nut on the right hand side. YOU DO NOT HAVE TO TAKE ANYTHING APART TO SEE THIS, IT'S OUTSIDE THE CASING. If it's not a spun prop, this is surely the cause. Let us know what you find. This makes a good case for twins or at least a kicker. I had twin 45's on my CD 22 and of course twins on my TC255 now.

Charlie

gary allen · Posted: Thu Jun 04, 2009 11:29 am Post subject:

Charlie,

Thanks so much for the advice and great detail diagram. I'm going to take the boat out of the water in the next day or two (didn't have the tow vehicle with me yesterday), and I'll begin investigating per your suggestions.

I did take the prop off at the beach and didn't notice a rubber bushing, but I'll check that again.

And thank heavens for twins. It would have been a real long slog with a small kicker across 10 miles of ocean. And with no back up, I would have had a major problem.

Gary

Wefings · Posted: Thu Jun 04, 2009 12:01 pm Post subject:

Look for bits of rubber around the hub .Most often seen on the inside or fore surface . The hub is a rubber "cushion" inside the prop between the shaft and the outer hub . Sounds like you spun it . It can be re hubbed by a prop shop
Marc

Captains Cat · Posted: Thu Jun 04, 2009 12:24 pm Post subject:

Gary, if it's the prop, I just found a spare one from my 45 Honda's, pretty good shape, aluminum. Look at the side of the prop, it's stamped on there. If you need it, I'll send it to you, no charge.. When I go out to the shed, I'll look at what size mine is.

Charlie

rogerbum · Posted: Thu Jun 04, 2009 12:58 pm Post subject:

As already suggested, it could be the shift lever being misadjusted or not properly tightened. When I had the impellers changed on my twin Honda 40's a couple of years ago, the Lake Union SeaRay guys screwed up the adjustment on the shift linkage on one engine. It worked for a little while and then quit on me in the middle of a short trip. The symptoms were the same. So, if you don't feel it drop into gear, it's most likely the shift adjustment, if you do, it's most likely the spun prop.

Roger

gary allen · Posted: Thu Jun 04, 2009 1:30 pm Post subject:

Charlie and others,

Thanks for the great advice and for your offer, Charlie. I'm going to pull the boat out of the water on Saturday, and I'll see what I can figure out.

What a great group of folks!

Gary

Chuckpacific · Posted: Thu Jun 04, 2009 4:32 pm Post subject:

Amen, Roger, on the shifting rod....I experienced the same thing after having had my yearly maintenance done by a Honda dealer. Sea Wolf Joe had me up to speed in no time...it's just a matter of doing some simple adjustments and then joining the two parts of the shifting rod.

DaveS · Posted: Thu Jun 04, 2009 6:16 pm Post subject:

I had problems with the shift lever (and I'm referring to the "throttle controls at the helm). Several years ago I noticed that one of my two Johnson 50's would not exceed x RPMs when I throttled up. What it turned out to be was that one of the screws had loosened on one of the shift levers so that engine was not it gear. A simple tightening up of the screw after gaining access to it and all was well. The reason the engine wouldn't exceed x RPMs (I say "x" because I don't remember what it was), was because there is a limiter to prevent over revving the engine without a load on it.

Capital Sea · Posted: Thu Jun 04, 2009 6:47 pm Post subject:

Much has been said about bringing a spare prop on a longer trip. What other outboard components should one have along? My 22 is powered by a Honda 90. Does it have one of these rubber bushings?

starcrafttom · Posted: Thu Jun 04, 2009 7:33 pm Post subject:

The rubber bearing is part of the prop. You should have at least a spare prop with all the parts to change it. carter keys. nut etc..I would also carry a fuel filter, air filter, a spare fuel bulb, hose clamps for fuel line, spare water pump impeller, and of course a tool kit and duct tape.

gary allen · Posted: Fri Jun 05, 2009 12:37 am Post subject:

Well, I ended up being able to get out to the marina this evening, and, sure enough, it turned out that the shifting rod had come loose. Apparently when the mechanic at Guenther's Marine changed the impellers, he did not tighten it properly and it soon worked its way loose. Not a comforting thought as to his competence.

Thanks to all of you, especially Charile and Roger, I knew right where to look and was able to attach and tighen the adjusting nuts. It was shifting into gear again, and the prop performed well in a short run.

I learned something from the experence, and the quality of this forum was confirmed again.

Gary

Chester · Posted: Fri Jun 05, 2009 4:23 am Post subject:

The shift rod is simple when you know what to look at... When you don't know what it is or how it works , well, that's a different story.
One of the things Sportcraft Marine did to us was to leave one of the motors stuck in reverse. Not a pleasant situation, especially when it is the first time you put the boat in the water.
No one cares about your boat as much as you do. Knowledge is your friend. If you can find a mechanic and-or dealer that has pride in their work make friends with them and post their names. We need allies in the business.
BTW, we like the redundancy of multiple motors too.

Alyssa Jean · Posted: Fri Jun 05, 2009 9:55 am Post subject:

Swap props and see if the problem moves to the other engine.

Captains Cat · Posted: Fri Jun 05, 2009 8:57 pm Post subject:

David, he fixed it. It was the shift rod.

Charlie