1995 Polaris magnum 425 will not run with airbox hooked up

[Kurt Reiser]

Frank there is a vacuum line coming from the oil reservoir going to the airbox then the two vacuum lines that go onto the carburetor they are all clear. Which direction but I want to go with the needle up or down

Edited February 27, 2019 by Kurt Reiser

[Frank Angerano]

Ok the reason I’m asking:

1. I’m wondering if there is a problem with the vacuum where as soon as you hook the air box up the vacuum lines are drawing all the air from the air box starving the air flow into tye carburetor. Why? No clue! Just wondering if that’s what’s going on. May sound stupid but you never know   

Try to move the needle on the carburetor and see how that goes.  Make sure you remember where the clip was on the needle before you move it. 

  If that’s not the fix then disconnect all hoses going to the air box, reconnect to the carb and try to run the bike and see what happens.   

Side note. That clip and spring set up in the carburetor can be tedious. Parts can fly off and never to be found again. Work in an area that will prevent that from happening.  

[Kurt Reiser]

Sorry to ask this again should I move the needle up or down?

[Frank Angerano]

Never be sorry to ask.  Better safe then sorry.  Moving the clip to the top notch lessens the amount of fuel coming in. Moving the clip to the bottom of the needle allows more fuel to flow.  

Where is it at now ? (The clip)

[JacobSlabach]

haha yeah make sure you are where you wont lose parts.  I almost lost the c-clamp off my sportsman carb yesterday....and I was in my workshop lol

[Frank Angerano]

Any progress? 

[Kurt Reiser]

 Just got finished raise the needle did nothing

[JacobSlabach]

hmm  could you upload some pics of the bike (like the carb, air box etc?)

[Frank Angerano]

Hoses connected  to the air box like the vacuum etc ? Did you try to disconnect them lines and reconnect to the carb and see how that is ?

[Kurt Reiser]

I just got called into work I will load pictures tomorrow when I go back to my garage thanks a lot guys

[davefrombc]

Did you check the carb to see if it  had  both the  air screw  and the fuel  screw? I can't see the  air box being a problem  unless either the  main  duct to  atmospheric air  is severely  restricted or the air filter  plugged.  The amount of air a vent or vacuum line connected to the  box would affect would be absolutely minimal .

When  you  move the  clip on the  slide needle , you  should only try one  notch at a time up  or  down at a time  from the original  setting .

[Frank Angerano]

I agree with the air and vent/vac  lines having minimal impact on the air box and it’s baffling.  I’m just trying to look at everything.   @Kurt Reiser has said he’s checked for any obstruction on all openings air filter etc so how can this be? Very strange.  

[davefrombc]

That's why I suspect a  plugged passage or the carb has both an idle air screw like most  carbs , but may also  have a fuel mix screw ..  The ones I see illustrated like the one in the video  I  posted are  not the thumbscrew  type but look  more like a  regular  plug screw ( for want of a better term )

 

[Frank Angerano]

Agreed.  

[JacobSlabach]

10 hours ago, davefrombc said:

Did you check the carb to see if it  had  both the  air screw  and the fuel  screw? I can't see the  air box being a problem  unless either the  main  duct to  atmospheric air  is severely  restricted or the air filter  plugged.  The amount of air a vent or vacuum line connected to the  box would affect would be absolutely minimal .

When  you  move the  clip on the  slide needle , you  should only try one  notch at a time up  or  down at a time  from the original  setting .

I agree👍  Although....  I moved my needle on my sportsman's carb up two notches...  problem solved.  no more adjustment needed- the bike runs perfect.  Its got to be something big that we are just missing to be causing the bike to just not run....  Are you sure its starving for air and not fuel?  I mean it seems pretty obvious to me that its air...  but I wouldnt just rule out the fuel till you're sure.

[Kurt Reiser]

Frank I was having problems signing in for some reason I’m very illiterate when it comes to these computers what I said was I don’t think it would be a carburetor problem both carburetors are doing the exact same thing. there is  only one screw on the bottom of the carburetor I’m not quite sure if you asked that question it seems like it’s something very simple because the bike runs great as long as you don’t hook up anything to the back of the carburetor it’s bizarre There are no obstructions in the airbox there are no obstructions in any of the vacuum lines I will check the cam and check the valves check the plug have move the needle up-and-down one groove at a time.Sorry if I sound repetitive I’m just getting so frustrated

Edited March 1, 2019 by Kurt Reiser

[JacobSlabach]

If its worth it to you, I would love to take a look at your bike if you brought it down to me-  I cant come to you because I'm under-aged and cant drive yet😣

im in christiansburg VA.  If you are interested, massage me privately and I can send you my address.

but if you want to figure this thing out on your own, I totally understand!  I'm just really curios as to what the issue turns out to be.

[Frank Angerano]

@Kurt Reiser I can’t begin to tell you how many times I’ve looked at something over and over just to find I did miss something. So being repetitive is not a bad thing.  

Edited March 1, 2019 by Frank Angerano

[Kurt Reiser]

Frank I’m not sure if it was you somebody asked for pictures of the carburetor I believe here they are