50hp Johnson revs in forward

[pontoonsixpack]

While under power usualy higher speeds the engine will rev way up as if the prop is cavitating or wrapped in weeds. No weeds and it will be fine if I stop and put it in gear again. Other times if I sit at idle or stop the motor it will not go into forward unless I put it in reverse first. What spins here?

 

[HighTrim]

Re: 50hp Johnson revs in forward

Welcome to iboats. I would guess you spun your hub. Draw a line across the prop and hub with waterproof marker, run the motor in the water until you hear it revving, pull it out and inspect mark. If no longer lined up your hub is spun and will need to get it repacked or get a new prop.

 

[pontoonsixpack]

Re: 50hp Johnson revs in forward

First time boat owner and your assistance is greatly appreciated. Thanks for the suggestion that I spun the hub. Will have this checked out. Happy boating.

 

[Molaker]

Re: 50hp Johnson revs in forward

it will be fine if I stop and put it in gear again.

Does this mean you stop and take it out of gear then put back into gear or does it mean it is no longer in gear and you have to put it back into gear? HighTrim may well be correct in suggesting prop slip, but it could be the lower unit dogs slipping out of gear either because they are worn or the shift linkage/cable is not allowing it to go fully into gear.

Other times if I sit at idle or stop the motor it will not go into forward unless I put it in reverse first.

This statment leads me to believe the latter.

 

[pontoonsixpack]

Re: 50hp Johnson revs in forward

Molaker - The not going into forward gear is when I stop and go into neutral after running awhile. This does not happen all the time...probably 50% of the time I need to put it into reverse to go forward again. You mentioned the cable. When I put it in forward (without revers first) the engine revs up without prop spin. Everytime I reverse first no problem going forward. Will check the linkage, pull the prop, and have the lower checked out when I pull the boat out this fall. Still works but an annoyance the way it is.

 

[Molaker]

Re: 50hp Johnson revs in forward

It sounds as though your shift cable may not be the right length adjustment.

A simple test/check would be to disconnect the shift cable at the engine. Put your control box handle in the neutral position. Then manually shift your motor to the neutral position. The end of the now loose shift cable should line up closely with the shift linkage you just disconnected it from. If it does not, readjust the cable adjustment until it does and reconnect the cable.

It could still be the lower unit dogs or gears, but this is a no cost check that should be done before spending money on it.

 

[pontoonsixpack]

Re: 50hp Johnson revs in forward

Thanks, Free checks & suggestions for a quick adjustmant work for me. Do I need any special tools to do the cable and pull the prop? Misplaced my manual and the web hasnt been to helpful getting even a diagram to look at without paying for a new one.

 

[Molaker]

Re: 50hp Johnson revs in forward

No need to pull the prop to check if it is slipping. Just do as HighTrim suggested and mark the prop and the prop nut so that if it slips the next time you go cruising, the marks will be misaligned. Use an indelible marker or something to put a fairly deep scratch in it.

As for special tools to check the shift cable - none needed, just common tools. You have not said what year your motor is, so I cannot tell just how the cable connects to the shift linkage. However, most likely you will have to remove the engine cowling (cover) and disconnect the cable end from the shift linkage with a 3/8" socket or wrench. If in question, the shift cable is the one that moves first when you push the throttle towards forward or reverse. It will fit on a threaded stud with a 3/8" self-locking nut and flat washer, so take care not to drop them in the drink.

 

[pontoonsixpack]

Re: 50hp Johnson revs in forward

1999 50HP Johnson 2 stroke
Will take my tool box with me and give it look. As for the spun hub this may be a second problem unless this next statement makes sence and explains both my problems with this motor.

With engine off I put the shift lever all the way forward. Then went and hand turned the prop. It spun freely both directions???? Dont think it was in gear at this point.

 

[Molaker]

Re: 50hp Johnson revs in forward

Sure sounds like it's just not moving the shift linkage enough. It could yet be something bad in the lower unit, but making sure your shift cable is adjusted correctly would be the first step. At this point, I'm betting you can fix it with an adjustment.

 

[pontoonsixpack]

Re: 50hp Johnson revs in forward

Thanks for the advice and suggestions to fix this ol putt around. If I can make this quirk go away there will be a peace of mind we wont be stranded and the family can enjoy our time each weekend together more. Have been stranded...but thats another story. Happy Boating