Loss of Power and Vibration

I recently bought a 2002 Tige 20i Direct Drive. Last month I made the mistake of running over a sand bar at the river and the prop (Acme 3 blade) didn't survive. So I switched over to my spare (Acme 4 blade). After doing this I noticed a slight vibration and loss of power, primarily during the hole shot when pulling a rider. This only lasted for a few seconds each time and everything else seemed to be fine. I thought the prop might be cavitating. I got my 3 blade fixed and put it back on. Now the problem is even worse. Not as bad as with the bent prop, but bad. I have a major loss of power and vibration every time that I accelerate with or without a rider. It happens during the hole shot and/or whenever I quickly accelerate at all speeds. It last anywhere from 3-4 seconds up to 30 seconds.

The props are straight and spin freely by hand. The drive shaft looks straight with no visible damage. The tracking fins do appear to be out of alignment. When looking from the back the front 2 are off center bent to the right. The third (rear) fin appears to be straight. Would this cause the problem I described? What else could it be?

Does anyone know how/where I can get it quickly diagnosed? I'm in San Diego and the boats at Martinez Lake/Colorado River (Yuma, Az.) The boat is new to me, so I don't have a mechanic yet. Can you recommend one that does not have a huge waiting list at this time of year? Thanks.

the shaft could be bent inside the strut. a very minor bent will cause a vibration. If i were you i will stop using it, you can force your transmission/engine. Hope u find a mechanic quick

On a previous boat I had bent the tracking fins pretty bad and it didn't cause any noticable problems.

On the other hand, a bend in the prop shaft that is not noticable to the eye can cause major problems.

Your best bet is to take the boat to a repair shop that can do this kind of work. Note that not all shops can, and the quality of work varies a lot.

There are at least two diagnostic functions that should be done:
1) Check for a bent shaft
2) Check the alignment of the shaft to the motor.

I've seen some talk on other posts (regarding similar symptoms) about checking for low transmisson fluid levels...any thoughts on this?

From what you said happened and what it's doing, have the prop shaft checked before you do more damage.

have you thought about a brand new prop? when i was having a vibration problem, i spent a lot of time checking my shaft and had a mechanic use a micrometer. a new prop fixed it. if you have access to a prop shop, ask if you can try one and bring it back if it doesn't fix the problem.

About 20% of props cannot be fixed, even when they look and spec out right. Under load they flex in unpredictable ways due to metal fatigue. I would have the boat checked for shaft alignment and put on a brand new Acme. The tracking fins would not be the cause of your issue, but quirky handling and lower top end.

I was originally thinking prop too, especially with the rebuilt 3 blade but now that I have had similar symptoms with 2 different props I had just about ruled that out unless somebody can tell me that cavitation is common with the 4 blades, there would be no other way to explain why it was performing this way.

By the way if it is the drive shaft...does anybody have any idea how much that's gonna cost me (ball park)? and how long it will take to replace (if I can get an appointment)?

if its's just the shaft it won't be much...but you could have bent the strut as well..it's hard to nail down a price...labor is going to get you on this one. anywhere from 200-300 or upwards of 600-700 is my guess. Stop driving on it and get it to a mechanic.....the more you drive with the vibration the more possible damage you can be causing. my advice take it to a good mechanic.....they can have it fixed by the weekend....take it to most dealers this time of the year and you'll be waiting 3-6 weeks.

have you tried to turn the prop by hand. Spray the strut bearign with a hose first and try and tunr the prop by hand...if it moves fairly easy your shaft is fine...if it's tuff to turn...shaft is more than likely bent. you can soemtimes eye the strut for straightness. either way have it checked.

Thanks for all the help. I'm off to the river tomorrow to take a closer look at the boat and try to figure out what I'm dealing with. Either way I've got a service appointment at Corona Watersports on 08/04...I hope this one does'nt break the bank!!

similar thing happened to me about a month ago. got to close to shore and hit bottom. killed the engine immediately. after pushing back out, bad vibration and no power. trailered the boat and prop was twisted pretty good. took to prop guy who stated he may be able to rework prop but looked like shaft was out of alignment. took to dealers recomended shop and they said needed new strut, shaft and something else down there. 2000 bucks. suggested i contact insurance. didn't even think about it, but thats why we have it right. had shop fax insurance estimate and they cut a check for 2000. total is actually 2200, responsible for 200 deductible. not bad for new strut, shaft and new acme prop. still getting old one reworked for spare. took 3 weeks to get boat in shop but took it in monday and got call about 20 minutes ago, it's ready. just in time for another hot weekend. I'm a first time boat owner and everyone said it's a well, but i love it. good luck and just my .02, but get it fixed right and contact insurance.