Just finished replacing the steering assembly, it all fits and it's good as new and most of the steering slop is gone, which was the original reason why I wanted to replace it. Also 270degrees is 100% the same one as the OEM one.
After opening the old assembly, I found you can potentially fix the loose steering without buying a new one. Read below.
I purchased this
Seastar jetboat 270 degree steering assembly from eBay.
When it came, I found out right away that it was not identical to what I have. The one purchased above had threads on the shaft where the one from Yamaha slotted into the tilt steering without threads.
Being lazy to return, I decided to swap the shaft with the old one. Which I found was pretty straight forward. Oh also the picture below is the NEW shaft with the OLD steering assembly because I already finished installing. But I figure I should take some pictures to explain what I did.. maybe it will help someone later on.
1. I found out the reason why my steering is so loose is because the white hold down thingy was worn out. It's there to keep the gears pushed against each other. You can probably replace it or put a washer there to act like a spacer. This is one of the many areas that cause the steering to feel loose.
2. Because I did not pay attention, I bought the wrong one with the wrong shaft. So I ended up just swapping the old one in. There is a snapring here. Just get it out enough to slide it down a bit. No need to remove it completely.
3. once you get the snapring off. You can push the shaft in a little to reveal this other locking ring. I used a pair of pliers to push this off. Pretty sure there is a tool for this but I don't have it. Once that's off you can slide the whole shaft out. Also, where the shaft inserts into this gear is where another cause loose steering can be. The slot the shaft goes in is not 100% tight. If you put some aluminum tape or something similar you can probably make this area extra tight. Not necessary though, but it will further tighten the wheel. Both the new and old shaft had the same tolerance. To assembly just do the reverse. Make sure it's all centered.
The other area where the steering wheel is loose is due to the tilt steering because it wears down. I'll probably replace that or figure out how to tighten it up.
You can probably just buy the correct replacement but the one I got was 150 bucks. 100 or more cheaper than the Yamaha one. Also because I wasn't paying attention. Not sure if they sell the Yamaha one cheaper elsewhere.
Hope this helps someone in the future. I figure someone will want to see pictures of the inside.
