How do I change the sponson mount bracket on yamaha waverunner?

I have the same problem on my 2000 Yamaha 1200 XL one of my sponson’s bolts broke off.
However I didn’t understand your response on how you said you fixed it. Could you please explain it a little better? How did you get the threaded rod in their? The bolt plate is inside the hull and Inside a sealed double walled chamber so you can’t get to it. Where did you drill the 1/2” hole, from the inside hull or the outside hull?
On mine of the four bolts that hold it in place it was the larger front one that originality sheared off. I took it to several boat repair shops, but no one was willing to work on it. So I tried fixing it myself. I bought a new sponson and filled the hollow interior with bondo and that gave me a completely flat surface to epoxy it onto the boat hull. I then bolted it on using only the three remaining bolts and I just left off the front bolt. Well it didn’t work. Actually I made a bad situation worse, because after just a short little test ride it sheared two more bolts off before I stopped.
Now I don’t know what to do I’m now missing three of the four bolts that would normally hold the sponson onto the hull. And there’s no way I can see to get to them other than tearing the whole wave runner apart. This is a really annoying problem because other than that one missing sponson the rest of the wave runner is in perfect condition and it runs great. And I can’t really use it because it’s pulls hard to one side without it.

Greg
August 2010

Did this work for you? I have the same problem on an xl800 ....

Phil
May 2010

Since no one answered I assume no one knows how. So this is what I did. Used a 6 mm hex coupling nut to add a new piece of threaded rod. Had to use a 1/2 inch hole saw to enlarge hole in the hull and siliconed it after tightening down the hex nut.

OldDusty
February 2010