2000 90HP johnson slips out of gear

[buckeyboy]

First off I would like to say hello to everone here this is my first post on the forum and I am looking for a bit of help.
I have a 90 hp johnson year 2000 outboard, when at high rpm running at almost top speed the motor will suddenly slip out of gear if I throttel down it goes back in. Also when crusing along then I slow down a knocking noise, I have done lots of reading here but still not sure. Clutch dogs? any input would be appriciated.

 

[ezeke]

Re: 2000 90HP johnson slips out of gear

Check for a spun prop first. The propeller should have inner and outer hub with rubber between which slips on impact or from age and heat.

Scribe a mark across the hub using the cotter pin as a pointer. If the pointer moves when running, either replace the propeller or have the hub rebuilt at a prop shop.

 

[buckeyboy]

Re: 2000 90HP johnson slips out of gear

Check for a spun prop first. The propeller should have inner and outer hub with rubber between which slips on impact or from age and heat.

Scribe a mark across the hub using the cotter pin as a pointer. If the pointer moves when running, either replace the propeller or have the hub rebuilt at a prop shop.

Thanks for the quick reply, I live in RI and cant get the boat in the water till spring time, is there any way to check it out of the water?

 

[ezeke]

Re: 2000 90HP johnson slips out of gear

Not really, though a propeller shop could probably tell.

Have you had the lower unit off recently or since the problem started?

 

[5150abf]

Re: 2000 90HP johnson slips out of gear

"jumps out of gear" and "knocking noise", sounds like it could be a clutch dog.

When was the last time you changed your lower unit oil?

Just draining the lower will tell you alot and I would start there.

Drain that(2 screws right side of lower unit) and post what comes out, look for metal shavings as it drains.

 

[tashasdaddy]

Re: 2000 90HP johnson slips out of gear

when you remove and replace the lower unit plugs, always replace the seals. also you control cable may have stretched, if original, and may need adjusting at the motor connection.

 

[buckeyboy]

Re: 2000 90HP johnson slips out of gear

Thanks for the additional replys, yes after this happened the first time I changed the lower unit oil. it was a little on the dark side and the was a small amount of filing stuck to one of the drain plugs.. the knocking concerns ne more because its constant when I slow down.

 

[tashasdaddy]

Re: 2000 90HP johnson slips out of gear

remove the shift cable at the motor. then shift it manually and see if it still does it. do you get any vibration, you did not have before? did you hit anything, is the prop damaged.

 

[tashasdaddy]

Re: 2000 90HP johnson slips out of gear

i realize you have to wait till you have water instead of ice. sorry for that!!! LOL.

 

[ezeke]

Re: 2000 90HP johnson slips out of gear

Just to be clear, you said that "if I throttle down it goes back in". That is not like a clutch dog problem, but like a prop that is starting to lose its grip on the bushing.

Or it could easily be that your cables or shift rod length are not set correctly.

 

[buckeyboy]

Re: 2000 90HP johnson slips out of gear

remove the shift cable at the motor. then shift it manually and see if it still does it. do you get any vibration, you did not have before? did you hit anything, is the prop damaged.

No I never hit anything. got the boat last season and it did it ever since. performance wise seems just fine hops up on plane very quickly. slips out once in a while and that clunking when I slow down..

 

[buckeyboy]

Re: 2000 90HP johnson slips out of gear

Just to be clear, you said that "if I throttle down it goes back in". That is not like a clutch dog problem, but like a prop that is starting to lose its grip on the bushing.

Or it could easily be that your cables or shift rod length are not set correctly.

basicly I have to shift into neutral then it will take right off again. also like a stated chattering noise there always when slowing down. dont want to get stuck out there..

 

[Cricket Too]

Re: 2000 90HP johnson slips out of gear

How fast are you pulling the throttle back when you slow down and put into Neutral in order to go again?

If you are at WOT or cruisng speed, and you pull the throttle back too fast, you will cause the engine to knock, you need to gradually slow it down when your running at that speed. That could be what you are hearing, unless you can definitely tell it's coming from your lower unit.

If it is coming from the L/U, then I would guess maybe the dog is trying to grab when the pressure comes off of it, but I'm not sure if a dog would actually do that. I don't think a spun hub would make any noise when slowing down.

 

[buckeyboy]

Re: 2000 90HP johnson slips out of gear

How fast are you pulling the throttle back when you slow down and put into Neutral in order to go again?

If you are at WOT or cruisng speed, and you pull the throttle back too fast, you will cause the engine to knock, you need to gradually slow it down when your running at that speed. That could be what you are hearing, unless you can definitely tell it's coming from your lower unit.

If it is coming from the L/U, then I would guess maybe the dog is trying to grab when the pressure comes off of it, but I'm not sure if a dog would actually do that. I don't think a spun hub would make any noise when slowing down.

dosent seem to matter how fast I pull back. Guess I will wait for spring to see whats going on figured if I could find out now it would be a good winter project to repair it. or have it repaired. I am not a outboard mechanic. But I am a mechanic so depending on the level of difficulty I was willing to see what I could do. I appriciate everones input.