1985 50hp Evinrude E50BELCOB - No Thrust

[zamgod]

Hi,
Returning from a fishing trip a couple of days ago and with no warning engine began to rev up with no forward motion. Tried reverse gear....no propulsion! Tried forward gear...no propulsion! Managed to get home with Aux' engine.
On the floating mooring, started the engine and water is circulating. Put it in forward gear....no prop movement! Put it in reverse gear....no prop movement! Stopped the engine.
Took the cover off and selector lever on powerhead is working with remote lever. Put it into forward gear and turned prop by hand, the prop turned the flywheel and hence the engine. Put it into reverse gear and turned the prop by hand, the prop turned the flywheel and hence the engine. Both cases needed a fair bit of strength to turn the engine...not me a friend!
Can anybody help me? I just can't see how it should work by hand but not with the engine.
Thanks.

 

[LongLine]

Re: 1985 50hp Evinrude E50BELCOB - No Thrust

Pull your prop off & examine it. Spun prop? fishing line wrapped around inside?

Tom B.
(LongLine)

 

[5150abf]

Re: 1985 50hp Evinrude E50BELCOB - No Thrust

The only thing I can think of that would cause that is you are missing teeth off a gear, as the engine turns the prop it hits the part with no teeth and stops turning the prop but by hand you engage the good teeth.

Turn it through several revolutions of the engine, easier if you remove the spark plugs, and see if find a bad spot.

Also draining the lower unit oil will tell you pretty quickly if you have a problem as you will see metal chunks in the oil, beyond that I don't know, very odd probelm.

 

[zamgod]

Re: 1985 50hp Evinrude E50BELCOB - No Thrust

Hi,
Thanks for the feedback.
I'll try the prop first, I can do that on the mooring.
As for draining the LU, that'll have to be done ashore.

 

[zamgod]

Re: 1985 50hp Evinrude E50BELCOB - No Thrust

Hi,
I finally managed to get the boat ashore, extreme weather conditions hampered retrieval.
I've disconnected the remote cable from the shift lever and tried to select the gears. The lever moves back and forth "engaging the gears", with some resistance until I turn the prop. But in gear the prop just rotates freely......not engaging!
Any suggestions of the likely cause would be much appreciated.
Thanks.

 

[zamgod]

Re: 1985 50hp Evinrude E50BELCOB - No Thrust

I?ve done the test for a spun propeller, the prop?s OK.

My next project was to remove the damaged gearbox. The shift rod retaining bolt is pretty inaccessible, fuel pipes to the pump and VRO hampered access. I removed the starter motor and got the bolt out relatively easy. Removed the six bolts holding the LU, a little jiggle, and out she came.


But taking the gearbox to pieces was a much more difficult operation! Lots of cursing! I didn't have the special tools necessary to perform the operation. However have a go Joe, the box is of no use as is!

The prop came off easy. The prop shaft bearing housing was difficult, it was seized solid. After a few unsuccessful attempts I made up a puller using three 'U' bolts with one leg shorter than the other, so it would fit around the flange legs. It broke the seal and when the housing reached the lip of the hub I changed from the ?U? bolts to a made up straight ?J? pullers centred on the end of the prop shaft. The housing gradually slid from the hub.



The two snap rings were equally as allusive, until I ground down a long nosed pliers so that the jaws would fit into the holes. Then a couple of copper tube extension arms and hey presto they came out. Followed by the retainer plate, thrust washer, thrust bearing and finally the reverse gear. The reverse gear looks in good condition, with little or no wear.


Part II to follow, since one can only use 5 photos per post.
Seems a bit restricting to me, as they say "a photo can replace a thousand words"!

 

[zamgod]

Re: 1985 50hp Evinrude E50BELCOB - No Thrust

Part II of the Saga.



I could see the pinion at the bottom of the drive shaft, but when I tried to unlock the nut, by holding the shaft wrapped in cloth with vice grips, the pinion was just wobbling. A long piece of bent wire in the back of the pinion and out it came, it had sheared off the end of the drive shaft. I then removed the drive shaft which was straight forward.
Not only had the pinion sheared off the shaft but the forward gear was also chewed up, as can be seen above. The clutch dogs and the reverse gear look good, thankful for small mercies.

To remove the prop shaft, forward gear, oil pump and clutch dog the shift rod has to be removed. Which is pretty straight-forward. Just remove the cover boot and a slight tap on the cover to break the seal and slide it up. Push the shift rod down to engage reverse gear and unscrew the shift rod, taking a note beforehand of the rod height above the casing. The photo below shows the prop shaft removed and the chewed gears.



The following photo shows the sheared drive shaft/pinion gear, shim and cover.



Now all I have to do is find some spares or a replacement gearbox. Seemingly, finding a replacement gearbox isn?t so easy because there are a number of drive shaft variants in these 80?s boxes. Mine is a long shaft, 20inch, but you need to count the splines on top of the shaft and also the height of the shaft relative to the casing mating surface. My shaft has a number stamped halfway up 391376. But the BRP part number is 391162. After a lot of research the Evinrude agent said that the 391376 number is a casting number and to ignore it!
After a lot of research I've finally managed to locate gears, pinion, clutch dog and sealing kit from Outboard Spares Unlimited here in the UK's.
I guess reassembly and refitting should be a ball of fun!!