Polaris 440 Loading up

T

tutone

Member
I have a 2000 Polaris 440 XC SP that loads up when sitting at idle or running at low speeds.

What can I do to correct this?

I currently have 290s in, Air Screw set to 1.25 and what I believe to be a stock Pilot.

It runs great after burning out the fuel.......

Thanks!

Tutone
 
M

mride460

New member
snowbuff said:
Try setting air screws to 1.75. 1.5 should be min. But, I would try 1.75 and go from there.
Click to expand...


20zwtmo.gif
 
V

vic_junior

Member
Has is recently loaded up due to jetting changes? If yes, then it could just be your jetting being to rich. If no, then I would look at your floats and inlet valve/needle and seat. Make sure these are clean as a whistle. The smallest amount of debris around in the inlet valve could cause it to stick open and cause fuel to keep flowing into the motor even at Idle. Take carbs off and give them a good cleaning and make sure your floats are operating properly and are measured at the correct setting.

Could also be a leak in one of your fuel pump diaphragm's. The smallest hole in one of these could also cause your motor to load up at idle.
 
Last edited:
T

trailshredder

Member
vic_junior said:
Has is recently loaded up due to jetting changes? If yes, then it could just be your jetting being to rich. If no, then I would look at your floats and inlet valve/needle and seat. Make sure these are clean as a whistle. The smallest amount of debris around in the inlet valve could cause it to stick open and cause fuel to keep flowing into the motor even at Idle. Take carbs off and give them a good cleaning and make sure your floats are operating properly and are measured at the correct setting.

Could also be a leak in one of your fuel pump diaphragm's. The smallest hole in one of these could also cause your motor to load up at idle.
Click to expand...

Main jet has nothing to do with idle. He said the pilots were stock.......go with the air screw adjustment.
 
J

jimfsr

New member
enrichener circut... make sure it is seating properly, thats unmetered fuel at idle if it hangs open even a little bit.
 
T

tutone

Member
Needle and Seat

Thanks for all the information guys.

I have the carbs apart now and when comparing to a parts fische it looks like I am missing a washer that sits at the bottom of the removable seat.

Anybody know anything about these washers?

Thanks,

Tutone
 

Attachments

  • 440Carb.JPG
    440Carb.JPG
    34.5 KB · Views: 27
J

jimfsr

New member
It is a phenalic material. like a fiber washer, seals the seat to the carb body. Could be your problem, but I doubt it. You can try it and see. Might be able to buy it seperately, but it should come with a needle/ seat kit from mikuni.
 
T

tutone

Member
Washers

I actually picked up a couple of the washers yesterday, they seem to be brass.

they appear to not do a whole lot............

I will hopefully be putting it all back in tonight, I will let you know how it goes.

Tutone
 
T

tutone

Member
Better, but not quite there

Well, I have the air screws at 2 right now. The loading up issue is way better. I started at 1.75 and it was somewhat better.

I let the machine idle (after warmup) for 5-10 minutes and then took off. Still a small amount of gurgle on take off but seemed to burn off pretty quick. It might not be a loading up issue, I can let it sit for 30 seconds and get the same results. What do you think?

I am going to try 2.25 to see if it gets better.
 
N

nickelbagforme

New member
tutone said:
I have a 2000 Polaris 440 XC SP that loads up when sitting at idle or running at low speeds.

What can I do to correct this?

I currently have 290s in, Air Screw set to 1.25 and what I believe to be a stock Pilot.

It runs great after burning out the fuel.......

Thanks!

Tutone
Click to expand...
When's the last time you cleaned your valves, I had the same stutter on my 02' 500, cleaned the valves and all was good. Dirty valves can effect both low or top end.

If this is something that came on and was good before and the air screw, pilot and mains weren't touched, why would they need to be changed/adjusted.

Dirt .....
 
T

tutone

Member
Exhaust Valves

I am pretty sure that I cleaned them last winter (late). I will check them again.
I bought this sled 2 seasons ago. The stumble, loading was always there but just got bad last year. after cleaning the carbs, putting in those washers, and adjusting the air screws it has gotten considerably better.

I wish it ran as well as it does when its cold (the motor)! Snappy!

Thanks!

Tutone
 
X

xcr440

Well-known member
The jetting on that sled must be good for the cold, they are usually jetted for colder temps, -10 to 10 above, anything warmer, will seem like its loading up, because its getting more fuel than needed for the warmer temps.

You could always jet it per conditions.
 
S

snowbuff

New member
Did you make sure your choke plungers are seating all the way? You should be able to grab the lever and pull it out about 1/8" before resistance. If you can move it more than that, the plungers may be sticking a bit, causing a false "choke" condition. Also, you may want to pull the pilot jets again and clean or replace them. If they get anything in them, they will cause problems. If you cleaned them late last year, chances are they need it again. Then re-check with air screws at 1.5 not 1.25.

Also, pull and check the reeds.
 
You must log in or register to reply here.
Top