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Polaris magnum 425 cam shaft spec.

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Old 08-20-2015, 04:12 PM
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Default Polaris magnum 425 cam shaft spec.

Hi everyone, my Polaris magnum is really gutless new air filter, carb cleaned, jetted, adjusted.
I have the valve cover pulled and inspecting cam looks to be fine but would like to measure it does anyone know the specs.. aka lobe height.
Thanks Rob
 
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Old 08-20-2015, 04:41 PM
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Intake and exhaust lobe height: 1.2884 - 1.2924 (32.726 mm - 32.826 mm)
Lobe limit: 1.2766 (32.426 mm)
 
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Old 08-20-2015, 04:45 PM
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Originally Posted by old polaris tech
Intake and exhaust lobe height: 1.2884 - 1.2924 (32.726 mm - 32.826 mm)
Lobe limit: 1.2766 (32.426 mm)
Thanks,OPT
I'll let you know what I find
 
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Old 08-20-2015, 07:15 PM
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I measured the lobes exhaust 1.281 intake1.279 can't figure it out unless this machine is just slow get on a steep hill and you have it floored (thumbed) and it barely goes up..
When I rev it in neutral it takes it a bit to fully rev, but it will not get that high of rmp range while riding unless going down a hill, it always starts right up runs good just gutless..
 
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Old 08-21-2015, 05:20 AM
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May not be engine related. Pull the black wire from the reverse limiter module,if that doesn't help may be a belt or clutch problem limiting engine rpm. Worn ramp buttons in the driven clutch can also cause problems like this along with the old plastic limiter collars on the drive clutch spiders if they happen to back off. Don't know what year model you have on this.
 
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Old 08-21-2015, 07:57 AM
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It's a 96 magnum 425 4x4
Were is the reverse limiter so I can try and find the black wire?
Another thing I noticed was a bunch of oil build up in the bottom of the air box, I don't know if that's related to anything just thought I would throw it out there.
Thanks OPT
 
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Old 08-21-2015, 08:33 AM
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Limiter right below the ign coil #27. Just pull the black wire to defeat it and see if it helps. Dirt Cheap Yamaha, Polaris, Suzuki & Kawasaki OEM Parts & Accessories – Cycle Parts Warehouse You don't have the plastic limiter nut on this clutch,but still may be clutch or belt related if you can't get the rpms up. Make sure the air filter is clean,plus not a bad idea to recheck that you have the e clip properly on the carb slide needle. Should be on the 3rd notch from the top,plus has a white plastic collar on top of the needle assy that the diaphragm spring holds down. If installed wrong this can cause problems.Items 1- 4. Dirt Cheap Yamaha, Polaris, Suzuki & Kawasaki OEM Parts & Accessories – Cycle Parts Warehouse
 
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Old 08-24-2015, 03:24 PM
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Been real busy but today checked it out rev limiter already disconnected..
So no change there.
Took diaphragm cover off e clip on slide needle was 3rd bitch from bottom started running a little better when revving rode it a minute now I go to start it and it doesn't want to run unless I turn the choke on and stay on the throttle, how many turns out should air adjustment screw be on bottom of carb, and now I'll probably have top re-jet as well now..
Thanks Rob
 
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Old 08-24-2015, 05:19 PM
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Been real busy but today checked it out rev limiter already disconnected..
So no change there.
Took diaphragm cover off e clip on slide needle was 3rd notch from bottom started running a little better when revving rode it a minute now I go to start it and it doesn't want to run unless I turn the choke on and stay on the throttle, how many turns out should air adjustment screw be on bottom of carb, and now I'll probably have top re-jet as well now..
Thanks Rob
 
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Old 08-24-2015, 05:39 PM
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If the block off plug has been removed on the fuel(idle jet) screw,from a lightly seated position turn the fuel screw out 2 turns. As engine warms up you need to be able to use a small screw driver or carb adjuster to fine tune the idle. Most usually end up around 2 1/2 turns out,but depend on engine condition,jetting, etc. Stock should have a 140 main jet,40 pilot jet.
 


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