fountain 47 props touching each other when running ?
 

This is my thought... had a friend running at 1000 island poker run this w-end. slight shock in the steering was felt, that's about it, rpm went up... stopped and 1 drive was torn off...

feels like port drive prop hit center drive prop. snapped the drive shaft joints, then drive shaft spinning would hit the drive housing causing it to break then drive came off hold only by shifter cable and bellows...

would the center drive be able to spin the prop on stbd drive gear case?

if trimmed too high, maybe, that is the only real problem I can find...

did someone else ever experienced this problem?

some more

last

look at the skegs... not even broken, that's why the overtrim idea is the one held... do you guys have trim limit switch on your triples ?

WOW!!! :eek: Sure lucky it did'nt sink.
can't wait to here what caused that to happen.

If u trim them completley diferent ,,they will actually touch ...but the 380 tabs...should not be on there in the first place or cut of at the inside corner to clear while steering !!!!!

My guess is either trimed wrong and touched then ripped off, or ripped off , then touched !!!!????:party-smiley-004:

Maybe overtrimming could have snapped the U-joint and at high rpm broke the gimbal THEN causing the drive to drop down and hit the center drive.


BTW: I cracked a XR case by overtrimming but luckily it came apart at only 2,000 rpms while coming off plane....didn't do that much damage!!

U joint

that was also my thought at first, but when I saw the center drive spun the prop on the stbd drive gear case (look at picture) I then thought the same thing happened to port drive on the center or vice versa...

Anyway, we'll fix it and will run this w-end!

hoew do you explain the center drive prop hitting the stdb drive gear case?

the center drive sits lower than the port. When the gimbal snapped the drive got tossed around L-R by the water pressure rushing by and dropped in the process. That prop kept spinning for a few seconds until hitting things stopped its momentum.


at least my theory.........even after taking it apart you might never know.

Very simple......it the drives are not brought up even or not even at a turn that will happen. I went through two sets of props on my triple because of that mistake, I made with trim. Also notice how much lower the center drive is vs. the outside. If the center is to high it brings the outside drives closer. Notice the tie bar. Tom

Yeah, that is weird...

I know on my 47' you can not turn the wheel all the way to either direction with the drives trimmed up. The center one will hit the outer.

Yep, operator error. Trimmed center drive too high. Were his drive indicator cables hooked up and functioning? Maybe he was trying to shoot a rooster tail or something. Mechanical drive indicators would have told him where the middle was (too high) in relation to the other two.... I'm sure nobody's madder than he is!

Just a wild guess/question but if the inner port tie bar failed somehow? wouldnt that cause the port drive to kick back and forth freely hitting the center drive pushing it full right and cause that to hit starb on the lower part of the case?

I did some test. when trimmed abovethe ''trim limit switch'' level that the boat don't have, even trimmed all equal, the center touch either the port or stbd drive when turning, and pretty bad depending on how far you turn.

when trimming only the center drive, you would not believe how much both outside drives turn in toward the center drive !

to avoid this problem, you first have to make sure they are all trimmed equally, and second, make sure they don't go too high.

when drives are trimmed normally, if you lower the tabs and turn up to a certain degree, the props can hit the tabs...

Pretty tricky when you don't know about this... until you find out ! I would install shorter tabs out of the factory to avoid this problem... looks like they don't...

You would have to drop the tabs all the way down. No reason to do that on a 47' but it can be done.

so post #10 was dead on......hhhhmmmm I learned this the hard way as well...