96 Polaris 780 SLX carb settings

[daddio101]

Hoping for some help understanding the proper carb settings for above machine.

The manual I have lists highspeed screw settings as follows;

Font. 11/8
Center. 7/8
Rear. 11/4

Slow speed: all 3 set to 1 3/8 turn.

I understand the slow speed setting but have no idea what the settings mean for the high speed.

Any ideas?

Thanks!!

 

[bently]

Re: 96 Polaris 780 SLX carb settings

The settings are in turns out from the setted postion. 11/8 is 1-1/8 turns out from setted for example. They are just starting points and plug checks will be needed to fin tune the mixture. You are looking for a rusty brown color on your plugs, black is rich and has too much fuel, white is lean and not enough fuel. By turning the screw clock wise will lessen fuel and counter clockwise adds fuel. The center carb getts some of the fuel oil mixture from first and last cyclinder and is why the difference in screw turns. The front cyclinder will run hotter then the other two because of how the water exits the top of the cyclinders thru the cooling rail. There is a modification to correct this if you are interested.

 

[Froeman]

Re: 96 Polaris 780 SLX carb settings

I have a '96 SLX. I recall reading that you need to test the top end by riding at WOT then killing the engine, then looking at the colour of the spark plugs... that will tell you how the high speed screws need to be adjusted. Correct? Assume adjust 1/8 turn at a time?

Please post link to the cooling rail mod.

Thanks!

 

[bently]

Re: 96 Polaris 780 SLX carb settings

yes, small adjustments, here is the cooling rail mod. You can also put the water outlet in the front of the cooling rail at the mag cyclingder, that is where I put mine and corrected my cooling problem.

http://www.greenhulk.net/forums/sho...=269729&highlight=cooling+rail+mod#post269729

 

[Froeman]

Re: 96 Polaris 780 SLX carb settings

Thanks - I see the motor in the pics is a 650. Does the 780 have the same issues? I don't think I'll muck around with this because I've never experienced any issues. I think my mag cyl is a bit warmer but it has never been an issue (that I know of). I do know my plugs are wet and black when I remove them so my ski is prob running a bit rich. Might lean it out for more speed,.. Or might just leave it to be safe... Any opinions about this??

 

[bently]

Re: 96 Polaris 780 SLX carb settings

All of the Polaris engines cool the same way water is pushed up thru the jugs and out the cooling rail attached to the heads. The cooling rail has the exit at the rear or PTO cylinder. The water that exits the PTO cylinder has an easier rout to exit, that being said the Mag cylinder has the most resistance to push water out thru the cooling rail. That is why you can add the exit fitting and tube to aid in getting the hotter water out of that cylinder. It will allow you to even out the carb settings for the ski.