1958 qd-19 Crankshaft and Driveshaft

[Cresliner2012]

I have been working on an old 1958 Johnson Seahorse 10hp motor. I was able too get about four days on a lake and then noticed alot of high reving of the engine. Almost as if it's sliping out from Reverse & forward gear. After taking the motor off of the long shaft I have noticed what looks like ware and tear on the grooved teeth that the crank and driveshaft fit together. Am wondering what the best way too take care of this problem. I am guessing their is no way too actual fix these parts and am looking at having too get a new outboard or find the same model with working parts. I am hoping this is the problem but am worried that maybe it could be something more simpler such as ajusting the forward and reverse linkage.

 

[Daviet]

Re: 1958 qd-19 Crankshaft and Driveshaft

Was it actually jumping in and out of gear, or did the engine just rev up and the boat slow down?

 

[HighTrim]

Re: 1958 qd-19 Crankshaft and Driveshaft

Post a pic of your driveshaft splines. Not your issue of over revving though. Rare they are damaged actually.

Likely a spun prop, or possibly cavitation. Try a replacement prop to determine if it is spun. If you do not have a spare, draw a line across the prop and hub and run it until is revs, if the line is now askew, the prop is spun and will need to be rehubbed or a new prop bought.

If that is not it we can look into cavitation issues.

 

[Cresliner2012]

Re: 1958 qd-19 Crankshaft and Driveshaft

The boat seemed too rev up really fast loosing power. With slowing down it would re engage and move the boat along. But again while listening too the motor a clicking sound seemed too come from the engine.

 

[Cresliner2012]

Re: 1958 qd-19 Crankshaft and Driveshaft

I am unable too get pictures at this time as my camera is making the pictures so large and are past the recomended upload size. The teeth from both the drive and crank shaft are still visible and am starting to wonder if this cavitation could be my problem. Could you explain more what this is. The motor it's self has been in storage for about 10 years. And as I mention was able too get the boat on the water four times before this problem started. Can striking say a floating piece of drift wood cause cavitation issues.

 

[Daviet]

Re: 1958 qd-19 Crankshaft and Driveshaft

Have you checked the shear pin, hitting a piece of driftwood could shear it.

 

[Cresliner2012]

Re: 1958 qd-19 Crankshaft and Driveshaft

I have a new shear pin that was put in this evening. Haven't had a chance too test the motor in a tank yet. Need a new gasket now since removing the actual engine from the entire lower unit.

 

[Cresliner2012]

Re: 1958 qd-19 Crankshaft and Driveshaft

Crankshaft and the drive shaft are fine. Their is no way this could be the problem. I have made sure that they interlock and they doo very well. I have been pointed into the direction of the clutch. This is the sliding type of clutch and have the understanding that they can ware down. Problem is as follows.

Engine will rev up fast with boat slowing down. Was able too get about 10 hours of time on the water before problem got worse. The prop is fine. And I do not think it has spun. (as i've been told can happen) Am wondering a good place too look for clutch gears for this 1958 johnson seahorse 10hp qd-19.

 

[Chinewalker]

Re: 1958 qd-19 Crankshaft and Driveshaft

The clutch dog does NOT give a smooth slow down when it is worn. Rather, it will act as if you hit a log with a loud THUNK! Check your prop's hub. It will do exactly as you've described. You usually cannot tell by simply looking at the prop. Mark the outer and inner hub with a Sharpie and run the motor, making it slip in the process. If the marks no longer align, it is the hub.

Can't be ventilation or cavitation if you ran it fine previously and didn't change anything in your set-up (motor angle or height).

Only way it could be the driveshaft/crankshaft connection is if the waterpump was serviced once upon a time without the splines being greased upon reassembly, resulting in the crankshaft splines rusting out.