Another motor problem.

[Jeremy0407]

I was trying to find out what could be wrong with motor so I can fix it myself before paying those high prices for someone else to do it. It is 2005 Nitro 700LX with a 90 Mercury on it. The boat was running fine last week, after a day of fishing I trailered it and noticed all three of my blades were broke off. Do not recall hitting anything but I guess I did. That was my third prop so I decided to go with a stainless steel prop. I put it on earlier in the week and finally put it in the water Saturday. Everythings fine while at idle but when you put it in gear it starts vibrating a little bit. Give it just a little more gas and the vibration quits. Did not go fast in it at all because I did not want to worsen the situation. The only option I have heard so far is maybe a bent prop shaft. I will check that when I get home tonight. Any other suggestions.

[sac-a-lait]

all 3 blades of the prop are broken off? This has happened before? Man, you tough on them motors...Stainless stell might NOT be the way you want to go...I would rather a blade break than the lower unit....Either way, sounds like you bent something in the unit...

[ky-slabseeker]

Chances are good if you broke 3 blades off your prop you have bent your prop shaft. You can spin the new prop with your fingers and pretty well tell if the prop shaft is bent bad.I have a 75 hp merc on my boat and I went from alum to stainless and when I did I picked up a little bit of a noise at idle speed. It was told it was from the weight of the heavier prop.I have been running it for 6 years and no trouble so far.I would probally suggest that you let a mechanic take a look at it.Because if you have vibration you are gonna wear out seals, which in turn will destroy bearings and you will soon be replacing everything in your gearcase.... Good luck to ya....

[Castoff]

Inconceivable that the blades would be broken off and not notice a severe vibration, unless you were powering the boat onto the trailer . Or has anyone been following you very close but would doubt this since all three were broken off which indicates the shaft was rotating. Or kids gone bad? Buy a replacement prop and agree, have a mechanic check the shaft. Can get worse!

[ShilohRed]

Drain oil out of lower unit. Bet you will find pieces of metal coming out of it.
And if so look out ifs not cheap to rebuild one.
Last one I redid was $1500. And that was only parts.
Only thing is Theres no way to break off all three blades and not feel it. Unless your drinks were strong. LOL
Pete

[Shellback]

Stainless props aren't good for conditions where you might strike bottom. They definately will tear your lower unit up faster than an aluminum prop.