TOPIC: '59 Fat Fifty possible lower unit issue UPDATE

So anyone have any ideas why I could be cruising along at 3/4 throttle, gear shift in full forward and have the engine high rev like it went into neutral, without the shifter being moved? Did that to me twice today, among other things, see my post in the main forum on being stupid. Also seemed like it wouldn't come out of forward after this happened either. Of course in all my excitement I may have been trying to change gears while the throttle was still too far forward. Still doesn't explain the simulated going into neutral isse.

Any ideas?

Bob

slop/adjustment in the shift linkage?

had a in/out of gear issue with my '58 fat fifty today too...

bob, i had the same experience the 2nd time i took the boat out 6yrs. ago. i was runnin along at close to wide open when all of a sudden it sounded like it popped out of gear and just revved. i was able to get back to the ramp only at a trolling speed, anything more and it would just rev. posted on the forum and found out it was a spun prop. theres a rubber doo-hickie in there that lets loose for some reason and has to be re-placed. cost me $50. ron

Choose one:

Cavitation
Bad probeller hub
Clutch adjustment
Worn clutch dog & gears
Worn shift rod bellcrank

Well tried to look at the boat issues but was getting carried away by all the damn mosquito's!!!!!!!!!! Unhooked the shift linkage and tried to shift gears. Went into forward and neutral easy enough but had to try a couple of time to get it to go into reverse. Tried that 5 or 6 times with the same outcome every time. tried spinning the prop while in neutral and it would only go about 1/3 of a turn the would become hard because it was trying to turn the motor over. Did that even if it was in forward, reverse or neutral. I'm guessing I'm going to have to drop the lower unit and split it to see what's going on. I was hoping to be able to take her out in rememberance of my sons birthday August 5th but I don't think that's going to happen now. I've got to move my daughter next weekend so don't know at this point.

I'm assuming that I should be able to spin the prop all the way around in neutral. I know should remember that but CRS is kicking in. So focused on the trailer and other crap I have going on it's slipped my mind.

Thoughts?

Bob

Bob,

Maybe I can makeup here for the not-so- great advice to mill those cylinder heads you tried.

On any outboard, it is important to have the engine running when you are trying to shift it. If you have the boat out of the water and the engine turned off, you can rotate the propeller to take the place of the engine running.

The reason for this, is to allow the clutch and gear faces to engage one another without damage. In this engine, there are only 2 tabs on the face of the clutch dog. When you move the shift lever, the shift yoke pushes the clutch to neutral - forward-reverse. In neutral, the clutch dog is disengaged from the forward & reverse gears - sort of floating between them on the prop shaft. Because the forward & reverse gears are on opposite sides of the pinion, they spin opposite directions. When the clutch dog is pushed against a gear, the "ears" of the dog slide into a machined circular slot on the gear hub. This slot has two "ramps" an it that are 180 degrees apart. The ears on the clutch dog are also 180 degrees apart. When the ears of the dog strike the ramps on the gears, you hear a tumping klunk as the surfaces strike eathother - then the dog locks into place. Take your right & left hand and make "crab legs with the fingers. Now make the fingers on the left hand fill the spaces between the fingers on the right. Not push them together so they lock. This how the clutch & gears work. The gears never stop turning when the engine is running. They stay in the same place on the shaft at all times. The clutch does all of the moving back & forth. Problem is, if the engine is not running, or prop not turned while trying to shift, the tabs on the dog may jam against the ramps on the gears. A slight turn of the prop in either direction will allow the shif to be completed. NEVER force the shift lever is it jams and will not go full into gear. Turn the prop till it drops into gear normally. Forcing the lever will bend or break the shifting mechanisim. Never people play around with the shift lever in your boat when it is parked. Kids LOVE to do this. A broken clutch is a big deal. Because the tabs on the clutch and the ramps on the gears are 180 degrees apart - it is normal to have the prop free spin up to a half turn or more when rotating it back and forth. This is normal. Mercury and later OMC engines have a clutch with a bunch of ramps that are close together, so they will not act like this. They either engage fully, or make a clicking sound as the prop is turned by hand.

Your engine has a clutch detend adjustment under the powerhead - on the right side of the motor, just inside from the shift lever. Be sure it is adequately oiled & greased. The cam may be out of adjustment, and the cable could also be out of whack. Adjust the cable and levers so it goes all the way into forward and neutral. It must click into neutral without making chattering sounds. If it can't be adjusted to stop the problem there is something that's worn & needs to be fixed.

Be warned, a "spun" prop hub can feel solid when turning it by hand. This is because the rubber in a spun hub gets smoking hot - and when the power is let off - the rubber fuses to the prop again. But it will break loose again when you ask a lot of it. You must compare the prop on it now with one that you know is good. Signs of a spun hub are the shear pin hole getting closer and closer to the propeller hub snout, and the hub sticking out of the rear (front) side of the prop where the gearcase is. They can be very tricky to diagnose if you don't have a good prop to compare. Once you know what a spun hub feels/acts/sounds like, it will be very evident what the problem is..

Thanks Bruce. I took the prop off to look at it. Thank goodness i kept the old ones for reference. i have a wine tasting to go to then I'll check it when I get back. From the initial looks, It looks fine and I don't see any rubber in it to spin. Looks to be a metal center hub press fit (keyed?) into the prop blades. If it's there it must be a very thin layer. I'll take pictures later when I get back home.

Bob

Wine tasting? That is more important than getting your boat fixed and on the water?

Skip, yeah have to do what the boss says and it was really good food to go with it so.....

Ok so here are some pics. The first two are the front of the props, new (black) and old (white). Look ok to me same orientation from the looks of it.



Now here they are from the back. Look a little different orientation wise but don't know if any tabs are suppose to line up with any notches or not.



So from what I can tell it's fine. Tried to turn the inner hub with channel locks just to see and wouldn't budge. I was king of hoping that was it, would suck sicne it's a enw prop with one 3/4 day usage but at least I would know it wasn't something in the nlower unit. Now I'm not sure what to think.

Bob

Hi Bob,
The rubber portion cannot really be seen once it is installed into the propeller casting (if in good condition). Although it is for a Mercury application, I am enclosing a picture of a hub assembly.
In the picture of your "new" propeller, is there any rubber showing (there looks like there may be)? As Bruce states, the hub would be quite bad to slip with the use of simple tools, as they will usually only slip with the load of pushing the boat.

Regards,
Joe
www.fergusonpoolemarine.com
This email address is being protected from spambots. You need JavaScript enabled to view it.

Take a laundry marker and draw a line from the hub to the bore of the prop. Let it dry. Re mount the prop & try the engine to see if the problem comes up again. If it does, remove the prop & see if the lines still are in the same place. If not, the hub is slipping.

The problem could also be cavitation. Try lowering the engine one slot on the tilt pin & see if the problem goes away. Be sure the engine is securely mounted to the transom and is not "walking" upward on the transom wall. These can become loose and fall off of the boat. On the big engines, OMC abandoned the thumb screw transom clamps in 1960

Thanks gentlemen, well marked the prop, put it back on and went to the ramp. Started the motor, lever was in neutral but lower unit wasn't! Thank god it was at idle. The damn thing was in reverse and stayed there when I shifted to neutral and forward. Took her back home and sure enough, took the shifter linkage access covers off and what did I find? Damn lower shift rod was out!!!!!!!!!!! Well that explains why she went into uncontrolled neutral twice and I could still limp back home. Caught just enough to get into forward. Also explains why it stuck in reverse after I tried shifting it a few times after getting home Sunday.

Removed the lower bolt, reconnected the rod and tightened back up. Should be good to go now for the rememberance run next weekend. Can't run her this weekend, have to move the daughter. Glad to no I didn't piss away money on a new prop, only to have spun it! Still keeping the old one on board as a precaution.

Now I think I should probably find a new bolt for that rod connector. Not sure why the other one let the rod drop out. It was tight. Maybe not big enough in diameter to keep the rod from slipping down. Was skipping over the tops of 1 1/2' waves coming back down the Potomac on Sunday so maybe a few things rattled loose. Gas line problem happened well before the wave skipping.

I think I also need to find a coupe shear pins just in case. Looked through the old tool box and almost every spare but no pins! Guess dad didn't plan for that OR used them up! Always good to have spares of as much as possible with these old beauties!

Thanks everyone! No on to the restarting problem.

Bob

Well had the same problem AGAIN!!!!!!!!! This is really getting old. Looks like the lower shift lever came out of the coupler again. I guess I'm going to have to get a new coupler and a couple of bolts to make sure it's all good to go. Unless the lower shifter lever is worn, but it looks good from what I can tell.

Is it possible to replace the connector through the window or does the lower have to be dropped?

Bob

Well the connector, bolts and star washers came in the end of last week and finally git it on today. Of course after having to drop the lower unit twice to get the connector and the lower bolt after it fell out trying to put it together! Can't use a magnet when it's aluminum so.......but it's done, Woo Hoo!! Now if I can just get her back in the water to giver a good run again. Unfortunately couldn't do it this weekend, 48 bags of mulch had to be put down!!!!!!!!!!! Yeah my back let me know about it. Heading to Pensacola this weekend for a week so won't get back in the water until I get back. Going to finally take some family time on the beach and see old friends.

Bob

Well I have another question relating to the lower unit. I had to drop it again today, well actually thought I had to but didn't really, but since it was off I checked the impeller, just fine and very flexible still.

Anyway the question is, should the drive shaft pull straight up and almost out of the lower unit? well when the water pump cover is off should it be able to almost come out? Memory is going to crap and I don't remember it being able to pull up like that when it's off.

Bob

with the water pump pulled apart you should be able to pull the drive shaft all the way out. That is if my mememory is right
Mike aka the pirate

Wheww, thanks Mike. I thought maybe I was loosing my mind!!!! It's been one of those weeks ya know!

Bob

Probally another 'correct me if I'm wrong' question. Reading through this post I cam to the spun hub replies. In the first pistures he shows a pin prop, in the answer by Ferguson Poole the pictures are of a splined prop. I thought the protection for a pin prop was the pin. Am I wrong for thinking that a pin drive prop also has a rubber bushing that might spin if the pin does not shear??

yes a pin prop has a rubber bushing. Now I have taken a spun prop and drilled down between each blade into the hub and then taped each hole and run a screw all the way into the hup. It works but not the right way to fix it. But sometimes you just don't have the money to fix it or buy a new prop.
Mike aka the pirate

Learn something new everyday.

Cool Mike thanks, always good to have a back up plan just in case.


Bob