My 2024 255XD Build/Mods

[Igetwet]

Any updates on this?

 

[F.M.]

Any updates on this?

Tuning on the cones? Washer setup?

 

[Igetwet]

Yes

 

[F.M.]

Yes

No shims port, 5mm starboard side.

 

[F.M.]

Welp.... I apparently still have quite a bit of cavitation I need to get rid of. The last two outings with 5-6 people in the boat and 2 adult size children on a double tube, it is really struggling to hook up. So much so that after a few seconds of cavitation, the boat drops rpms down to 5k and won't go above that unless you go all the way back to neutral and try again. Ended up having to move people around to distribute weight just right to get on plane. Kind of tells me that for a "surf" boat, Yamaha propped this thing all wrong. Maybe instead of being capable of 55mph plus speeds, it should be able to get a boat load of people up on plane. I can't imagine trying to surf with full ballasts and more than 2 people on board.

So I reached out to David at Leading Edge. Super friendly and eager to help whether I was ready to purchase from him or not. I highly recommend contacting him if you ever have any impeller questions at all. Ran thru my current list of mods with him and told him about the results @jacoviii has reported with the 12/18 vs the 12/20 options, with and without his L13 cones installed. He said that he could pitch two impellers for me that would designed to specifically work with the L13 cones I have already. Sounded pretty confident that he could get rid of my cavitation issues and add at least 2mph to the top end. So, we'll see, they should be here next week.

 

[jacoviii]

I'm excited to here your results.
If he can nail down a better top end and with the twins. this 100% game changer. But some have reported needing a second re-pitching after testing. So dont give up them each boat is different.
I liked my stock cones best so far while using the twins. I felt like the pumps were stuffed while also using the L13.. At that point you have to open up the outlet nozzles. But it was easier to remove the L13. I had a quicker throttle response with stock cones. So if he was on the fence at all about using L13..... He might be right.
When running twins and L13, 0 to 36mph fine . But 40 to 54mph climb felt slower. But if you don't spend much time on the top end. I think twins plus L13 is ok.
For anyone moving forward on this similar route. Do the twins first. Either off the shelf or from leading edge. The L13 helped but not the fix for surf plus max ballast.

 

[FSH 210 Sport]

Welp.... I apparently still have quite a bit of cavitation I need to get rid of. The last two outings with 5-6 people in the boat and 2 adult size children on a double tube, it is really struggling to hook up. So much so that after a few seconds of cavitation, the boat drops rpms down to 5k and won't go above that unless you go all the way back to neutral and try again. Ended up having to move people around to distribute weight just right to get on plane. Kind of tells me that for a "surf" boat, Yamaha propped this thing all wrong. Maybe instead of being capable of 55mph plus speeds, it should be able to get a boat load of people up on plane. I can't imagine trying to surf with full ballasts and more than 2 people on board.

So I reached out to David at Leading Edge. Super friendly and eager to help whether I was ready to purchase from him or not. I highly recommend contacting him if you ever have any impeller questions at all. Ran thru my current list of mods with him and told him about the results @jacoviii has reported with the 12/18 vs the 12/20 options, with and without his L13 cones installed. He said that he could pitch two impellers for me that would designed to specifically work with the L13 cones I have already. Sounded pretty confident that he could get rid of my cavitation issues and add at least 2mph to the top end. So, we'll see, they should be here next week.

So are you buying a set of twin screws? Buying a set of standard impellers?
I’ve spoken to him as well.. he’s very impressed with the twin screw impellers.

 

[F.M.]

So are you buying a set of twin screws? Buying a set of standard impellers?
I’ve spoken to him as well.. he’s very impressed with the twin screw impellers.

Twin screw.

 

[F.M.]

Got them installed finally. Only had about 20 minutes to spend in the water this morning, gotta go help my daughter move this afternoon.

Initial results seem to be spot on with @jacoviii has posted. Not surprised since we’re running the same boat at pretty much the same elevation with almost the same mods.

Cavitation is still slightly present at hard acceleration from idle, but I would wager to say reduced by 85-90%. If cruising on plane, hard acceleration is amazing up to 47-48 then slowly creeps up to 55. Hook up while cornering is a 200% improvement. Feels like a different boat in the turns. Top speed was 55 with half tank of fuel and just me onboard, which is only down 1mph from 56. 7700rpms port and strbd, which is down from 7800-7900 I was getting before. Gonna take the L13s off and go back to stock cones and give it another try again tomorrow. Hoping to get rpms back up closer to 7900 and get my 1mph back.

 

[Igetwet]

What are these “twin screw” impellers?

 

[FSH 210 Sport]

Got them installed finally. Only had about 20 minutes to spend in the water this morning, gotta go help my daughter move this afternoon.

Initial results seem to be spot on with @jacoviii has posted. Not surprised since we’re running the same boat at pretty much the same elevation with almost the same mods.

Cavitation is still slightly present at hard acceleration from idle, but I would wager to say reduced by 85-90%. If cruising on plane, hard acceleration is amazing up to 47-48 then slowly creeps up to 55. Hook up while cornering is a 200% improvement. Feels like a different boat in the turns. Top speed was 55 with half tank of fuel and just me onboard, which is only down 1mph from 56. 7700rpms port and strbd, which is down from 7800-7900 I was getting before. Gonna take the L13s off and go back to stock cones and give it another try again tomorrow. Hoping to get rpms back up closer to 7900 and get my 1mph back.

Which pitch did you get?

What was the temp ?

 

[F.M.]

What are these “twin screw” impellers?

Easiest way to explain it is two differently pitched impellers stacked on top of each other.

 

[F.M.]

Which pitch did you get?

What was the temp ?

The box said 12/18, but they were supposed to be custom pitched to get rid of most of my cavitation while not losing top end. So I think they did job. Still waiting on David to get man to me on specifics.

Air temp was about 78 this morning while I was out. Water temp was 89 off I remember correctly.