- Location
- Camano Island
I finally got my 760 conversion (61X) out on the water today. Here's what I think:
:Banane01:
I have no idea which impeller came with my 650 hull - never felt the need for a different one, so left it in the hull. I have an "I" prop, and a freeride prop. Both will get tested later whne I get my project hull in the water.
Here's my current setup:
760 resleeved 61X. Performance ported (according to NW Sleeves specs). I didn't increase the port heights any further.
Wiseco pistons.
Single 44 SBN. 32PSI popoff, 120 Pilot - .8 turns out LS, 150 Main - 2 turns out HS. I left the 44 unbored because I wanted the most bottom end torque I could get.
R&D girdled head with 35cc domes (haven't measured compression since installing these).
Factory B - Mod pipe. Bottom and top screws adjusted out.
OEM reeds (I know I should put something less damaging in - they're brand new, so I should be OK this season I'd think).
Lightened OEM flywheel.
Stock 650 CDI - I have a modified CDI to install into my other hull. I'm going to leave the 650 CDI in place since I'm just intending to break this engine in and get it all dialed in while I complete my other hull. Then the stock 650 is going back into this hull & the 760 will get transferred over to the "new" repaired/reinforced hull.
Out of the hole performance is great! The ski feels much lighter and I could launch respectably off the smallest waves!
I still need to iron out some carb issues, but I'm quite happy with performance so far. I dialed in the LS mixture screw and idle speed by nosing in to the dock (used the dock to resist against the jet thrust). I took her easy for the first hour or so (actually pretty much all day) - varying the RPM's, but after she was all warmed up (and cooled off) a couple times, I opened her up a little.
She's a bit squirelly (sp?). I swapped ends out of a couple turns, and kicked the back end loose easily. I'm running a Riva Groovy ride plate, so going back to a shorter plate (maybe a D cut plate) might keep the back end down.
I have to relearn how to balance with this setup. I found myself porpoising, just like I was a newbie again. Going to a shorter plate won't help this any...
Towards the end of the day, Gasgas, JeffP, and I were chasing each other around the lake. I took off on a couple high speed runs, and was quite impressed. I have a deep scoop intake grate. I think a toploader might have helped keep the ski hooked up a little better here (because I had to play with throttle position to keep her hooked up). When it did hook up, I felt like I was rocketing across the water.
I'm curious to see what the other guys thought when they were chasing after me...?:sneaky:
:Banane01:
I have no idea which impeller came with my 650 hull - never felt the need for a different one, so left it in the hull. I have an "I" prop, and a freeride prop. Both will get tested later whne I get my project hull in the water.
Here's my current setup:
760 resleeved 61X. Performance ported (according to NW Sleeves specs). I didn't increase the port heights any further.
Wiseco pistons.
Single 44 SBN. 32PSI popoff, 120 Pilot - .8 turns out LS, 150 Main - 2 turns out HS. I left the 44 unbored because I wanted the most bottom end torque I could get.
R&D girdled head with 35cc domes (haven't measured compression since installing these).
Factory B - Mod pipe. Bottom and top screws adjusted out.
OEM reeds (I know I should put something less damaging in - they're brand new, so I should be OK this season I'd think).
Lightened OEM flywheel.
Stock 650 CDI - I have a modified CDI to install into my other hull. I'm going to leave the 650 CDI in place since I'm just intending to break this engine in and get it all dialed in while I complete my other hull. Then the stock 650 is going back into this hull & the 760 will get transferred over to the "new" repaired/reinforced hull.
Out of the hole performance is great! The ski feels much lighter and I could launch respectably off the smallest waves!
I still need to iron out some carb issues, but I'm quite happy with performance so far. I dialed in the LS mixture screw and idle speed by nosing in to the dock (used the dock to resist against the jet thrust). I took her easy for the first hour or so (actually pretty much all day) - varying the RPM's, but after she was all warmed up (and cooled off) a couple times, I opened her up a little.
She's a bit squirelly (sp?). I swapped ends out of a couple turns, and kicked the back end loose easily. I'm running a Riva Groovy ride plate, so going back to a shorter plate (maybe a D cut plate) might keep the back end down.
I have to relearn how to balance with this setup. I found myself porpoising, just like I was a newbie again. Going to a shorter plate won't help this any...
Towards the end of the day, Gasgas, JeffP, and I were chasing each other around the lake. I took off on a couple high speed runs, and was quite impressed. I have a deep scoop intake grate. I think a toploader might have helped keep the ski hooked up a little better here (because I had to play with throttle position to keep her hooked up). When it did hook up, I felt like I was rocketing across the water.
I'm curious to see what the other guys thought when they were chasing after me...?:sneaky: