Prop disengagesslipping

"hey there everyone. new to t

"hey there everyone. new to this forum and did a search but found nothing. anyway...

just bought my first boat a 1994 cajun ski/fish boat. i took it out for a test ride today. problem was that trying to gain speed wasn't happening. engine idles perfect, starts perfect. motor absoultley runs beautiful. when i accelerate it starts out fine, but as i increase the throttle the boat won't plane out and if it seems to die out. if i plane out it seems like the prop is disengaging/slipping. or seems like i'm hitting constant air pockets. now when the prop disengages i drop the throttle back it seems that the prop re-engages.

i talked to a few people and they said that it was a trim issue. which could be because it didn't seem to be working. but this boat should be screaming. it's a 120hp johnson outboard. any input would be greatly appreciated."

"Try this: Make a mark on the

"Try this: Make a mark on the hub,(the part the prop shaft comes thru), and thr prop itself..run the boat again until the problem happens..look and see if the marks are now different..If so, re-hub the prop(slipping under load), if not, cavatation problem...Tom"

thanks for the input. is ther

thanks for the input. is there anyway to check the hub w/o taking it back in the water. if i took the prop off he back would that show anything?

thanks

"ok. i did what someone on thi

"ok. i did what someone on this message board told me what to do. i put a 2x4 in between the prop to lock it in position. like so...
prop 1"">
here is the 2nd pic with me turning the flywheel with a socket and holding the flywheel in place
prop 2"">
to me this seems like there is a lot of play in that hub. seems like there is about an inch of play. but let me know what you think.

thanks"

Does it go back when you let t

Does it go back when you let the pressure off? If not the bush is shot. How hard did you have to pull on the wrench to turn the flywheel?

it does go back after i releas

it does go back after i release the pressure from the socket. i was pulling very hard. but like i said on my 1st post that it seems to disengege at WOT.

if i bought a hub kit is that something i could at home on a workbench??

thanks

not to sure about the movement

not to sure about the movement of an inch(prop in rel to hub under load)...maybe re-hub as sugested above...wat is the plates height relation to bottom of boat(r'nt u running the motor to high out the water?? will cause cavitation and feel like air pockets)

"Hey Bob...The cavation plate

"Hey Bob...The cavation plate is the long one just over the prop..it should line up with the bottom of the boat..if its above it, the the motor will cavatate...needs to be lowered...A hub replacement is not a home job...hub is pressed in..a dealer can tell you where it find a prop repair shop.....Tom"

"the cavation plate is in line

"the cavation plate is in line with the bottom of the boat. but if this plate was out of line would the shift gear feel like it is slipping out of gear??

like i said it only does this in very high rpm's. about 4500-5500 and if i back off the throttle it feels like it locks back in gear and i can move again. i will take a pic of the cavation plate and post it. it looks to be on line with the bottom of the boat, but you guys would know better.

i ordered a new prop anyway. they say you should always have 2 props so...

i removed the old prop and i did notice metal shavings. they looked like brass shavings and some balled up rubber on the prop near the spindle.

thanks for the info guys. keep it coming. i need to get to the bottom of this"

"I am very interesting in this

"I am very interesting in this topic! As I have the same problem with my 1972 100HP Johnson, Model 100ESL72R. It was going really fine. At one point, I tried to increase speed to past half of the throttle, it acted up as if the prop was not installed. The boat stays at one place and the motor is screaming as if no gear has been engaged. I have the lower unit out. I tried to pry on the squashy rubber in the prop thinking it was a messed up gasket. I gave up and about to throw the prop away and go for a new prop. Also:
I placed the gear in forward before disconnecting the shift rod. But I noticed that I can hold the vertical shaft and spin the prop clockwise. It will keep going with the click noise of each turn. I am watching this topic for more help to see if I have a gear or solenoid problem beside the prop. I don't want to change the prop and end up changing the entire lower unit which is a thousand bucks so I was told.
Help please, help! I don't want to be stucked in the Bay anymore. My wife and all my friends are really afraid to get on my boat now.
Thanks
Q."

"Bob.... Have the boat on a tr

"Bob.... Have the boat on a trailer and the engine in the normal vertical running position.

Now, standing back away from the rig somewhat viewing it from the side, The cavitation plate just above the propeller should be parallel with the bottom of the boat. Should that plate be at a slightly upward angle, as the boat travels forward, that would cause the back of the boat to raise allowing the propeller to draw air (cavitation, ventilation, whatever one wishes to call it).

Obviously the result would be a propeller that loses its grab on the water.

Draw a line, marking the propeller and its hub with magic marker. Now, run the rig to experience the problem you're having, after which check that line you drew. If the marks are still in line, the propeller is okay. If the marks have moved, the hub is slipping.

--------------------

Quang.... If memory serves me right, I believe that the clutch dog on that model has a beveled edge in one direction. Meaning that in gear, you could still turn the propeller in one direction but not the other direction. If so, when turning the propeller in the direction that it can be turned, it would feel like you were forcing a spring loaded ball up an incline, then suddenly have it drop off a slight vertical edge, over and over.

Do the marking test as mentioned above. Let us know what you find BUT not in this thread. see the following.

(MarineEngine.com - Properly Inserted Post)

Go back to the previous page and click on the "Start New Discussion" hyperlink that exists in the "Blue Border".

This will allow you to enter your question/post under your own title heading which will then appear at the top of the list.

As it now stands, your post is buried under the post of another member.

When time permits, visit my store at: http://stores.ebay.com/Evinrude-Johnson-Outboard-Parts-etc?refid=store"

thanks for the input joe. i t

thanks for the input joe. i trimmed the motor down to make the cavation plate horizontal. it appears to be inline w/ the bottom of the boat...pics to follow. a new clue was found. i found rubber pieces on the prop by the actual hub which were stuck to the metal on the inside of the prop. these pieces looked like they may have come from that rubber piece in the middle of the hub. is this a sign of hub damage??
also as i was reading ur post. u were saying something about the back of the boat rising. this definatly does NOT happen at all....if anything it seems to get sucked in the water more than it should.

thanks

"here are some pics of the cav

"here are some pics of the cavation plate
motor 1
motor 1"">
motor 2
motor 2"">
motor 3
motor 3"">

does the cavation plate look to be in the correct place??

thanks"

No!

No!

"From what you've said, th

"From what you've said, the propeller hub is slipping, a common problem. It can be re-hubbed at any reliable propeller repair shop at a fraction of the cost of a new propeller.

I assume by looking at the rig that the engine has performed properly in the past with you or a previous owner..... so in which case the installation of the engine would be fine.

Note that the slight downward angle of the cavitation plate would have a tendency to cause the stern to lower itself, especially at a high rpm.... a scenario that could easily be corrected via the PTT while underway.

When time permits, visit my eBay store at: http://stores.ebay.com/Evinrude-Johnson-Outboard-Parts-etc?refid=store"

"yeah, the people from whom i

"yeah, the people from whom i bought the boat from take it in to be serviced every year. they gave me all the receipts. the grease on the splines look fresh. but i ordered a new prop on monday and it will be here tomorrow, figured i could use a spare anyway. so i'll give it a whirl tomorrow after work
thanks for all your help guys. i'll post something tomorrow if the prop fixes the issue.

thanks again"

"ok....all i can say i WOW how

"ok....all i can say i WOW how stupid am I??

anyway.. got the new prop installed it, very easy. took the boat out and the same problem occured. so i'm like WTF now..and some other words in there. well, i was very pissed so i held the trim down as far as it would go even past the part where the metal to metal contact occured and.........voila the boat ran like a dream. so what was i doing wrong? apparently the trim wasn't down enough. the first time i took the boat out i thought i put the trim down all the way because when it hit the metal i thought that was it, but i had to go father down where it inserts into the plate thing.

so everything is fine. to my stupidity. but is there anyway to make the motor go down into the metal bracket "smoother". it seems when i hit that point it's very very tight. could i file/grind a little off so it goes a little smoother??

thanks for all the help guys"

What are you saying? Are you s

What are you saying? Are you saying that it goes down fast and then slows down for the final part?Then that is normal there is nothing wrong. It is much slower in the trim function.

"Coming down from the tilt pos

"Coming down from the tilt position, the drop is fairly fast, then the engine hits the trim rams and the drop speed slows. That is the foremost outer trim position.

You then have 15° of in trim until you hit the bottomed out position, the start position. From this point, you have the mentioned 15° of trim out available, after which the tilt function engages."

"exact tumondo joe. when it h

"exact tumondo joe. when it hits the trim rams the motor seems to go very, very slow the rest of the 15°. is this normal or not.

thanks"

It has been mentioned that the

It has been mentioned that the trim function is very slow!!