425 Magnum main jet - Polaris ATV Forum
Polaris Magnum Discussions for the Polaris Magnum

 
LinkBack Thread Tools Display Modes
post #1 of 10 (permalink) Old 10-25-2010, 05:18 PM Thread Starter
Junior Member
 
Slow Poke's Avatar
 
Join Date: Jun 2010
Location: N Texas
Posts: 24
425 Magnum main jet

I have a 97 425 Magnum with a Supertrapp exhaust. I bought it this way, and it has always popped sporadically on decel, and feels a little anemic on top end. I'm thinking the main jet needs to be changed to account for the increased exhaust flow. What do you think? Anyone know what the stock jet size would be? Can I pull the jet without removing the carb?


Thank you for any help you can give.

Poke
Slow Poke is offline  
Sponsored Links
Advertisement
 
post #2 of 10 (permalink) Old 10-25-2010, 05:40 PM
Extreme ATV Enthusiast
 
mechanike's Avatar
 
Join Date: Jul 2010
Location: cary illinois
Posts: 280
you probably can use a 165 main,better too rich than too lean, plan on opening up your airbox? i have pic's of what i did with a permanent coffee filter.you probably have a 155 in there now.mines abit rich but screams so i will wait to i come aross a 165.aint paying no $5 shipping for no damn $3 jet you can put in an envelope.how many discs do you have in your exhaust?i have 9 and its perfect,,,,,,,,,,,,,,,,,,,,,

01SCRAM500/1-1/2" SPACERS/KENDA KLAWS/DOUGAS RIMS/GEN4 BUMPERS/CARBMOD/UNI/OWN AIRBOXMOD/Aaen/SUPERTRAPP/PILOT LITES/MASTERLOCK WINCH/POLARIS SPEEDO/97 TRAILBLZER 250/HIGH COMP/SHRIMPLITES/PAINTED BLUE/400CC CARB/MOOSE/Aaen PIPE/FMF SILENCER.
mechanike is offline  
post #3 of 10 (permalink) Old 10-25-2010, 05:51 PM Thread Starter
Junior Member
 
Slow Poke's Avatar
 
Join Date: Jun 2010
Location: N Texas
Posts: 24
I have 4 or 5 discs. 9 has to be pretty loud! I wasn't planning to do anything to the airbox, but I'm open to suggestions. I just replaced the filter stand for the 3rd time. Not real happy with that. 155-165 is a pretty big jump in main jet size. Is there a 160?

Can I change the main without pulling the carb?

Poke
Slow Poke is offline  
Sponsored Links
Advertisement
 
post #4 of 10 (permalink) Old 10-25-2010, 06:04 PM
Extreme ATV Enthusiast
 
mechanike's Avatar
 
Join Date: Jul 2010
Location: cary illinois
Posts: 280
yeh forgot you have a 425 which i heard is a 500 with a smaller bore.you might also only have a 152.5 which makes a 160 good,i was told that anything less than 7 discs is the same restriction for a 500 as stock,425 i don't know,,,,,the 9 discs sound good and throaty,with the air box,carb mod.i go 7 more mph in exactly the same distance so somethings working right.

01SCRAM500/1-1/2" SPACERS/KENDA KLAWS/DOUGAS RIMS/GEN4 BUMPERS/CARBMOD/UNI/OWN AIRBOXMOD/Aaen/SUPERTRAPP/PILOT LITES/MASTERLOCK WINCH/POLARIS SPEEDO/97 TRAILBLZER 250/HIGH COMP/SHRIMPLITES/PAINTED BLUE/400CC CARB/MOOSE/Aaen PIPE/FMF SILENCER.
mechanike is offline  
post #5 of 10 (permalink) Old 10-25-2010, 06:14 PM Thread Starter
Junior Member
 
Slow Poke's Avatar
 
Join Date: Jun 2010
Location: N Texas
Posts: 24
Mikuni carb? Where can I get a main jet?

Poke
Slow Poke is offline  
post #6 of 10 (permalink) Old 10-25-2010, 06:58 PM Thread Starter
Junior Member
 
Slow Poke's Avatar
 
Join Date: Jun 2010
Location: N Texas
Posts: 24
Well, I'm pretty sure the main jet is a 140. Who sells main jets? I think I will try a 145 and 147.5 to start. I will probably add some discs to the supertrapp, too. I'll let you know what happens.

Poke
Slow Poke is offline  
post #7 of 10 (permalink) Old 10-27-2010, 10:59 AM
Extreme ATV Enthusiast
 
mechanike's Avatar
 
Join Date: Jul 2010
Location: cary illinois
Posts: 280
hey, did you call the dealer to find out??i can send you a new 155 for free once you find out,if you open up your resrictive air box this might be ok,,,,ask around.you should be at the same elevation as me and my 500 comes stock at 155,,,,,,,,,ask them if you use a big round mikuni jet.

01SCRAM500/1-1/2" SPACERS/KENDA KLAWS/DOUGAS RIMS/GEN4 BUMPERS/CARBMOD/UNI/OWN AIRBOXMOD/Aaen/SUPERTRAPP/PILOT LITES/MASTERLOCK WINCH/POLARIS SPEEDO/97 TRAILBLZER 250/HIGH COMP/SHRIMPLITES/PAINTED BLUE/400CC CARB/MOOSE/Aaen PIPE/FMF SILENCER.

Last edited by mechanike; 10-27-2010 at 11:04 AM.
mechanike is offline  
post #8 of 10 (permalink) Old 11-05-2010, 08:35 AM
Extreme ATV Enthusiast
 
atvjunkie821's Avatar
 
Join Date: Dec 2009
Location: Middle Tn
Posts: 483
Check out this link on your 425. I have done a lot of testing on mine with a wideband O2 tuner. If you have the 140 jet it is way too lean even for factory. Run at lest a 155.
425 Magnum jet upsize

95 Magnum 425 4x4 , 518HO carb & air box, 12inch rear wheel conversion.

02 Magnum 500 RMK

If it ain't broke, I can't afford it!
atvjunkie821 is offline  
post #9 of 10 (permalink) Old 11-05-2010, 01:04 PM
Extreme ATV Enthusiast
 
mechanike's Avatar
 
Join Date: Jul 2010
Location: cary illinois
Posts: 280
there is someone on e-bay that only charges $2 shipping for up to 10 jets!!thats where i'll be,,,,,,,,,,,,,,

01SCRAM500/1-1/2" SPACERS/KENDA KLAWS/DOUGAS RIMS/GEN4 BUMPERS/CARBMOD/UNI/OWN AIRBOXMOD/Aaen/SUPERTRAPP/PILOT LITES/MASTERLOCK WINCH/POLARIS SPEEDO/97 TRAILBLZER 250/HIGH COMP/SHRIMPLITES/PAINTED BLUE/400CC CARB/MOOSE/Aaen PIPE/FMF SILENCER.
mechanike is offline  
post #10 of 10 (permalink) Old 01-31-2011, 03:45 PM
Extreme ATV Enthusiast
 
Beenthere's Avatar
 
Join Date: Jan 2010
Location: Maine
Posts: 238
I went from a 140 main to a 160 main and had to tune the carbs a little bit to make it work for me. It matters at what elevation that you are riding at. I'm at about 220' above sea level and I don't think I get much above 3000' where I do my riding.

95 Magnum 425 4X4
It is better to look foolish, than to open your mouth and remove all doubt!
Beenthere is offline  
Reply

  Lower Navigation
Go Back   Polaris ATV Forum > Polaris Model Specific Discussions > Polaris Magnum

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Polaris ATV Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Similar Threads
Thread Thread Starter Forum Replies Last Post
Carb Main Jet E clip location Nandy Polaris Sportsman 1 09-06-2010 07:52 AM
Main seal failure 46 pete ATV General Discussion 1 08-03-2010 02:51 PM
98 Xplorer will not run after main bearing replacement Palmetto Polaris ATV Repair and Maintenance 7 05-30-2010 01:46 PM
"98" Xplorer Main Bearings Palmetto Polaris ATV Repair and Maintenance 4 04-28-2010 11:31 AM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome