07-03-2011, 10:51 AM #1
93 sl650 wash/lean 780 air box ????
O.K took ski out for first real run after updates and it has no top end and running on lean side.Turned out mains and better but still lean.Question is I put a 780 air box on it with the sides cut, basicly a open element now.Would this be causing my lean cond. I searched and found that polaris updated mains to 105 on there replacement open elements is that something I should be leaning towards I'm running stock 77.5's now.Thanks, Nate
07-03-2011, 11:50 PM #2
- Join Date
- Oct 2006
- Cleveland OH
The stock 650 FA is very restrictive. Using the 780 FA with the open element will prob need more fuel like the OP Vortex FA's.
Ken at OP said you should only need to turn the highs out about 1/2 turn with the Vortex (very similar in air flow as the 780 FA)
Unfortunately Polaris recommends the larger main jets.
So, it's kinda unknown which to use.
I'd try the 1/2 turn out first and watch your wash CLOSELY!!!!
If it doesn't get better, then you WILL need larger jets.
07-04-2011, 09:06 AM #3
I've went over a half turn and its better but still lean no top end. Ordered 105's pop off tester ,tach.and bought 2 more vac. gauges to check sinc. This ski is going to run yet or its going to a real mech. if I can't get it figured out.thanks,Nate
07-05-2011, 11:47 AM #4
anybody else have idea's thoughts.....jumping from 77's to 105 mains seems alot....
07-05-2011, 01:19 PM #5
Hmm. I put Ocean Pro Vortex F/A's on my '94 SLT750. I have the carbs right about 1/2 turn out beyond stock settings with stock #90 jets and my wash seems just fine. I checked this weekend and my CEN was too rich and PTO was slightly lean. I made some slight adjustments that should put me right at perfect wash patterns.
I have a set of #100's that I'm guessing would put me just right with stock settings if I were to install them.
Jumping from 77 to 105 is pretty steep indeed. I think I have an extra set of #90's. If you want to try those I can drop them in the mail for you to test. If they work out we talk about a swap later.
07-05-2011, 03:17 PM #6
- Join Date
- Aug 2006
- Pittsfield, MA
07-06-2011, 11:49 AM #7
thanks for offer KJ but guy I sold ski to gave me a friday deadline or he wants $$$ back if I don't get it nailed down. And thanks Polaris nut I have seen info. when I did search / in one of your earlier posts. Guess I'll just drop the 105's in and see what happens at fact. settings for the 77's ???? !!!! thanks again, Nate
07-08-2011, 09:03 AM #8
Well testing on trailer the 105's seem to run better but my tto tach. leaves me confused on my rpm's by ear it does not seem correct I had a pop off of 16psi across the board.My carb's have 1.5 needle and seat,seems to me I read that they should be 2.0's somewhere. Also noticed after running on trailer that my mag diaprham is leaking fuel so I guess carb's will be coming back off again.Do you guys see fuel smoke in carbs after shut down. I noticed center and pto where doing this last nite. Nate
07-08-2011, 01:06 PM #9
Vapor coming out the carbs isn't uncommon.
These fuji motors are spec'd to have 2.0 needles and seats. Pop-off of 10-18 is the spec on the 750's.
The only place I see a 77.5 jet spec for the 650 is pilot jet. The factory manual calls for a #77.5 or #75 for the pilot and a #90 or #95 for pretty much all years of the 650 model.
On my '94 SLT750 I have the stock #75 pilot and #90 main jets with 2.0 needles and 16PSI pop-off. With the Ocean Pro F/A's I gave the highs an extra 1/2 turn and my wash is just right.
Are you revving this up on the trailer? That's a bad idea. Plus running without water should be minimal.
07-08-2011, 01:32 PM #10
running it on trailer at ramp in water............just like being tied to dock or tree..... 1993 sl650 77.5 mains/ high spd and 77.5 pilot /low spd clymers as far as needle and seat it currently has 1.5's. Now with 105mains/high spd set at fact. setting it runs better but I now have a fuel leak diaphram so with the carb's back off was wondering if I should change 1.5's out to 2.0's and what spring to run....Nate
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