Tweet
Took this piston out of my 97 GSX last year after the PTO piston deto again, this is a shot of the Mag piston. Just wondering if it looks lean or rich. This piston had roughly 20 hours on it.
Thanks Chris
Thanks Chris
Attached Files
-
Factory Pipe Spec 2 <br />愛&D Rec Head<br />意ovi 44XR Carburetors<br />FLY Flame Arrestors<br />感rimer Kit/Premix (40/1)<br />愛+D Aquavein Intake <br />Galindo Grips<br />愛+D 85/88 mm Hydro-force Nozzle<br />惹olas XO (16.5/24) Impeller<br />媲each House Sponsons<br />廈ydro-Turf Mats<br />嫂WD Bow Spray Deflector<br />廉armin Etrex GPS (61.5 MPH) -
Re: Piston Was Rich or Lean????
Looks pretty goo. I like to see a little more wash/color personally, but if it was critically lean you would have seen damage long before 20 hours.SBT Tech Support is here to help with your problems.
We try to answer each question quickly and accurately.
Please do not use Private Messaging for Tech Support, use the forums. -
Re: Piston Was Rich or Lean????
Thanks TS, this piston was from when I was running novi 44 with a 115 main, however my plugs had no color to them so I am now using 127.5. Do you think this is too much of a jump. I am still trying to get the jetting right. Many others are using alot lower main jets.
Thanks ChrisFactory Pipe Spec 2 <br />愛&D Rec Head<br />意ovi 44XR Carburetors<br />FLY Flame Arrestors<br />感rimer Kit/Premix (40/1)<br />愛+D Aquavein Intake <br />Galindo Grips<br />愛+D 85/88 mm Hydro-force Nozzle<br />惹olas XO (16.5/24) Impeller<br />媲each House Sponsons<br />廈ydro-Turf Mats<br />嫂WD Bow Spray Deflector<br />廉armin Etrex GPS (61.5 MPH)Comment
-
Re: Piston Was Rich or Lean????
Chris,
TS cannot answer your high speed jetting question without knowing your low speed jet size too.
When jetting carbs, you must retain an overall jetting number. On a 787 motor with your mods, it is usually around 240 - 245 total jetting.
So, if you had 125 low speed jets, you would need at least 115 main jets.
Remember, when running your motor above 1/3rd throttle, it is pulling fuel from both jets in each carb, not just the high speed jet.
I think your piston pictures look very dry and ready for some bad things to happen to them. Unless you washed them before you took those pictures, there is no sign whatsoever of oil and any moisture from piston wash. That indicates alot of heat, burning away all the oil deposits. You do need a larger total jetting number.Bill O'Neal <br>
WCM
<a href="http://www.watercraftmagic.com"Comment
-
Re: Piston Was Rich or Lean????
Hey Bill, The pics where taken about 9 months after I removed the piston so that is why they look dry. I am currently running 130 pilots and 127.5 mains, so by your recommended total jetting I am pretty rich??? Any advie would be helpfull. Another question would be what hard jetting would you recommend for the Spec 2 pipe as far as midpipe and waterbox??? I don't have a stinger but I will be usinf a FCV on the waterbox. Me ECWI has a 120 jet in it but it is before the ECWI not tapped into the fitting.
Any advise would be great. I would love to finally get my ski up and running right.
Thanks ChrisFactory Pipe Spec 2 <br />愛&D Rec Head<br />意ovi 44XR Carburetors<br />FLY Flame Arrestors<br />感rimer Kit/Premix (40/1)<br />愛+D Aquavein Intake <br />Galindo Grips<br />愛+D 85/88 mm Hydro-force Nozzle<br />惹olas XO (16.5/24) Impeller<br />媲each House Sponsons<br />廈ydro-Turf Mats<br />嫂WD Bow Spray Deflector<br />廉armin Etrex GPS (61.5 MPH)Comment
-
Re: Piston Was Rich or Lean????
My SS 787 with Novi 44's has 140 pilots and 120 mains, for a total jetting number of 260 ( ported motor likes alot of fuel at 7750 rpm).
Put a 120 main jet at the midpipe fitting and a 140 in the top of the waterbox.Bill O'Neal <br>
WCM
<a href="http://www.watercraftmagic.com"Comment
Comment