You can run either BKR5 or BkR6 with no problems.Sooty plugs are because it's running rich,too much fuel. If it's just leaking at the gasket on the fuel valve you can replace it,if the fuel valve is leaking,replace both! Item 22 and 23. Dirt Cheap Yamaha, Honda, Arctic Cat & Polaris OEM Parts & Accessories – Cycle Parts Warehouse
Carb kits are available on Ebay if you need one.http://www.ebay.com/itm/NEW-SHINDY-CARBURETOR-CARB-REBUILD-REPAIR-KIT-FOR-POLARIS-425-MAGNUM-1995-98-/290892668459?pt=Motors_ATV_Parts_Accessories&hash=item43ba8dde2b&vxp=mtr The foam behind the yellow prefilter is mainly for support for the air tube and holds the prefilter in place. Make sure the prefilter and main air filter are clean and the support foam isn't blocking the prefilter area..http://www.cyclepartswarehouse.com/f...1996&fveh=5413
The little rubber grommets on the carb brace are just rubber nutserts. You can get them at any hardware store.
As far as the fan not coming on,turn the key on and jump the two spade connectors on the fan sensor at the top of the radiator. If the fan comes on,this eliminates the fan motor as a problem and the sensor usually has shorted out because of heat. #13.http://www.cyclepartswarehouse.com/f...1996&fveh=5413 You can pay $36 for this sensor or get one at Napa or Auzone cheaper. Just take it out and match it up.Here's one similar.http://www.autozone.com/autozone/par...equestid=88134

 

old polaris tech, do you have an email or PM's you help through?

My dad has a '95 magnum 425 4x4 and its making a noise in the engine, I was thinking cam chain but seems tight, I've had the top cover of the engine and head side cover off and didn't see anything out of the normal. Its like a knocking sound, hardly noticeable when cold, gets louder when warmed up. Doesn't have that many miles on it, maybe around 1800. Ever see crank or rod bearings go bad in a 425?

 

Only time I've seen a rod go out on a 425 or a 500 was one(500) that the oil hadn't been changed in years and was thick as Stp. Noise could also be radiating from front clutch area. If guide buttons are worn too much,will have a slapping noise sounding like engine related. Look through this service manual,can help you with service and repairs.http://gh-ftp.com/ORV%20Manuals/Pola...0All%20Models/

 

The radiator fan is "activated" by the thermal switch in the upper (back) part of your radiator. You can check the fan itself by "bypassing" this switch and just feeding 12 volts to the fan. To do this, you probably will need to remove the fuel tank so you can reach down inside (behind the radiator) and unplug the thermal switch wire. Then you need to feed 12 volts to the wires that go down to the fan - if the fan is good, it will come on right away

 

OPT - I have a "stumper" that is making me pull my hair out! I have a 95 Magnum 425 that is blowing the coolant out the top of my water/antifreeze overflow bottle when the coolant starts to circulate. Thermostat is good, radiator is clear, radiator cap is good, water pump circulates. I don't think it is a blown head gasket as no white smoke, no water in oil. Bike runs fine - but once the coolant starts to circulate and I "gas it" the coolant mixtures blows right out the top of the reservoir cap (like a geyser). About the only thing I can thing of IS the head gasket, but no "usual symptoms" of that. What else do you think could be the cause???

 

Trapped air in the cooling system is the major cause of coolant blowing out the reservoir bottle. If you're sure the cap's good,no mud behind the radiator,fan's kicking on,jack the front end up with the tires off the ground. Let the fan cycle on and off several times as you add coolant to the radiator.You can squeeze the hoses to help aid in air removal.Both hoses should feel warm to indicate coolant is moving through the engine. Once you're sure all the air is purged,replace the cap and see how it does. If it still shoots out the over flow,I'd check the water pump impeller for any damaged/melted vanes or in rare cases the impeller can just sit there and not spin if the nut backs off.

 

old polaris tech, I've always ran polaris engine oil in my two Magnum 425's. As they are getting older, the machines get used some but its very short distances and start/stopped quite often (they get less than 50 miles a year, no riding trips, just utility work), it seems like the oil smells like gas. What other cheaper oil do you recommend to substitute? Does it need to be synthetic?

 

If oil smells like gas,change it and the filter and I'd go through the carb and install a new carb kit! Short trips are bad on oil,but should have gas in it!! Polaris has opened up the door to just about all possibilities on synthetic oil use. You can go with Mobil1,Amsoil,etc 0w40 synthetic oil,5w40 Rotella T6 or other brands,10w40 rated oil,even 5w50 in extreme hot weather. Doesn't have to be Polaris oil,just a good grade of synthetic suitable for your riding area,along with temperature range. My opinion,0w40,5w40 or even 5w50 in the hotter southern states can just about be used year round. Comes down to your choice really...http://polarislubricants.com/atv.asp Plus some other good reading is from Bob The Oil Guy. http://www.bobistheoilguy.com/viscosity-charts/