Hey guys, I recently acquired a 97 trailboss 250 for free. Long story short I ended up with a dime sized hole in the piston, so I'm doing a top end rebuild. While I'm at it, there are a few.mods I would like to do. The airbox is pretty screwed up, so I want to ditch it and use a clamp on k&n or foam type clamp on with an outerwears. I can only seem to find stock replacements. Does anyone have a part number to a clamp on filter that would work? I know I will have to play with the jetting, so my.next question is where can I get the carb jets, and what number would be a good place to start? I want to do a carb rebuild anyways. I also read about the slider mod, would that be a good thing to do as well? Also while I'm doing the rebuild, and intake mods, id like to do a clutch kit as well. Who makes a good clutch kit? My main usage will be woods, and dirt roads, so id like something that would be "sporty"

 

Carb kits are everywhere for the Trail Boss plus K&L Supply or many local dealers carry different size Mikuni jets. Other can tell you on clutch kits, carb slide mods if they've done so,etc.http://www.ebay.com/itm/Moose-Racing-Carb-Rebuild-Kit-For-Polaris-Trail-Blazer-Boss-/230954045375?pt=Motors_ATV_Parts_Accessories&hash=item35c5ef0fbf&vxp=mtr

 

I'm just having a hard time finding a part number or.correct size for a clamp on filter. So the ebay jet kit cones with more then one size jets?

 

carb kits comes with just "standard" oem jets. Just check any cycle shop close by,most like we did carried boxes full of different size Mikuni and Keihin pilot and main jets. Simple piece of cloth or string around the back of the carb and you can tell the diameter. Around 2 1/4" to 2 1/2 " but don't hold me to it. http://www.unifilter.com/clamp_on.html

 

Anyone recall what carb i should have , and how to tell? I'm very familiar with vehicle carb tuning, I don't see how a at would be much different. On at v's you still tune by the plug right?

 

28 mm Mikuni. Stock jetting is a 145 main jet, 40 pilot jet.

 

So I don't have to start another thread, how can I check to see if my.oil pump is.working?

 

Bleed the 10mm screw on top of the oil pump to remove any possible trapped air. You have to have the engine running and at an idle. Pull the oil pump arm all the way up with your hand and oil should slowly drip from the small tube leading from the pump leading to the cylinder base.Best if the small line is clear or replaced it to where you can see it pumping..If in doubt,just premix the first tank of gas 50-1. It will smoke a little extra if the oil pump is working but it's ok.

 

Where exactly is the pump located? I'm going to start on pulling the head today to see what I'm working with

 

Do a compression check before you pull the head! If it's over 120 psi work on the other things. Pump's located at the right rear of the engine,can't miss it! Hit the throttle and you'll see the pump arm move up from the split throttle/pump cable. Bleed screw's on the top of the pump.