Freestyle Looking for 62t 760 freestyle specifics 64x Decking Porting

Ride report. Holy crap. This thing is is a different ski. Bottom end is violent. I love it I cant wait to get my new prop on it. It hits so hard it's got me trying to get further over the nose to keep the ski hooked up and that's with my super short pole. It's great gobs of power everywhere. With one exception. When it runs out a few rpm's it starts to stutter/bog. You can let off and give it a second and it will come alive again. Keep it out of the high speed circuit and I pulls like a beast. The Ada head doesn't get so hot that it would instantly burn you but you definitely can't hold you hand on it for 2 seconds. I guess what I'm saying is I don't think it's getting too hot. Also you can lay your hand on the pipe past the water jacket and its bearable. So a quick run down on the specs again are 760 64x 200 psi both cylinders, .060 squish, 100LL av gas, riva freeride pipe, msd enhance 0 degrees static timing, vforce3 reeds, stock dual 44 carbs, 32 psi pop off. 135 main 115 pilots, low speed screw out 1.5 turns and the high speed out 1 turn. I love the way this thing comes on the power and I tried turning the highs out a little it seemed to soften the bottom some and still brought on the stutter when the carb came into the high speed circuit. I then went in a half turn and it seemed to take a tad longer before it started stuttering. So I closed the high speed jet all the way and maybe it got a little better. It was cold and I didnt want to burn up my motor the first trip out so here I am asking for help from all the carb tuning gurus. Oh yea and the water coming out of the pisser was hot but I could hold my hand in it.
 
Ride report. Holy crap. This thing is is a different ski. Bottom end is violent. I love it I cant wait to get my new prop on it. It hits so hard it's got me trying to get further over the nose to keep the ski hooked up and that's with my super short pole. It's great gobs of power everywhere. With one exception. When it runs out a few rpm's it starts to stutter/bog. You can let off and give it a second and it will come alive again. Keep it out of the high speed circuit and I pulls like a beast. The Ada head doesn't get so hot that it would instantly burn you but you definitely can't hold you hand on it for 2 seconds. I guess what I'm saying is I don't think it's getting too hot. Also you can lay your hand on the pipe past the water jacket and its bearable. So a quick run down on the specs again are 760 64x 200 psi both cylinders, .060 squish, 100LL av gas, riva freeride pipe, msd enhance 0 degrees static timing, vforce3 reeds, stock dual 44 carbs, 32 psi pop off. 135 main 115 pilots, low speed screw out 1.5 turns and the high speed out 1 turn. I love the way this thing comes on the power and I tried turning the highs out a little it seemed to soften the bottom some and still brought on the stutter when the carb came into the high speed circuit. I then went in a half turn and it seemed to take a tad longer before it started stuttering. So I closed the high speed jet all the way and maybe it got a little better. It was cold and I didnt want to burn up my motor the first trip out so here I am asking for help from all the carb tuning gurus. Oh yea and the water coming out of the pisser was hot but I could hold my hand in it.

I don't think you want your head that hot, what do your plugs and wash look like? How hot are the plugs after a high speed run? They shouldn't feel like lava.

Your making a poop ton of heat with that drypipe. I would dual cool that beast. Tap the top boss on the manifold and run the front of the head to a pisser. Use restrictors (before the pissers) in the winter to keep temps up if needed, it also keeps both cylinders at a closer temp.


This is a good tuning guide.

http://www.x-h2o.com/index.php?threads/carb-tuning-101-info-from-watcon.58480/
 
Well after a little research. I found a couple other setups like mine all were running a smaller main jet. Stock were 130 front and 132.5 rear. (This is also what factory pipe suggests) I have 135s installed. I think I'm just to fat. So this will be the first thing I change. Not ruling out the air box, but I am only running one screen and like the security of a cover to keep water out. Also how long does the motor need to run to get a carbon pattern on the piston tops?
 
i think cpt might be able to point you in the right direction on jetting.....shouldnt take to long for the carbon to show up....maybe 5 gallons...??
 
i think cpt might be able to point you in the right direction on jetting.....shouldnt take to long for the carbon to show up....maybe 5 gallons...??

Yea Chuck said he thought I might be rich. I might have burnt about a gallon so I'm going to change the Jets and run a little more fuel through it. I just wanna be cautious.
 
I suggest you make a quick run without the airbox to feel the difference, even a stock WB760 with a Riva drypipe has to change to filters or else it stutters.
 
Well I did what you said I made a quick run with out the air box today. By the way im only running one screen in the air box. And had no change. Still studders when I get in to the last 20 percent of the throttle. I think I'm rich but I think I will change out the 135s for some 140s just to see. My 130 and 132.5s will be here in a few days. What are others running on their 760s? I'm just curious.
 
Ok, what plug gap are you using? High combustion turbulence(more throttle = more turbulence) can blow out spark on gaps that are too big. With that compression, I would think .020. If that is not the problem then jet down.
 

davidescu_radu

sea riders
Yes - reverse jetting seem to be working better on the 760 set up(i have such on my rickter)
So increase low jet like 125 and decrease high to 110 and work with very low popoff - like waxhead said.
 
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