so i had my carb rebuilt and "set" last week put a new fuel filter on too..
i still keeps pouring out of the overflow on the carb bowl while the engine is running, but, at times it doesnt...so, i took it in to the shop and had them look at it again and what do ya know it stopped leaking when i got there(bogged out twice on the way there with fuel pouring out of the bowl)

they seem to think its fuel pump related, and ive been noticing while running the fuel filter(i have it before the pump) is completely empty, sometimes full, sometimes half full..

so the question is, can a failing pump sometimes not suck enough fuel, and sometimes pump too much and pump it into the carb so hard it floods it

 

Possible a fuel pump can be intermittent if enough dirt/trash is in it. Oem pump is around $48,the repair kit around $35 which is kinda stupid to rebuild one. Plus now with all the after market pumps,you can get them for 13 bucks on ebay. Cheap enough to get one and see it solves your problem.http://www.ebay.com/itm/Polaris-Scrambler-Predator-500-Fuel-Pump-Assembly-Replaces-2520227-/191193192549?hash=item2c84009865&vxp=mtr

 

do u think the fuel pump could be related to the fuel coming out of the carb..like sometimes could it give it too much pressure and over flow it?

 

Possible.. Fuel pumps are really just plastic and rubber valves that have a lot of places for dirt to collect. If you're sure the carb has been rebuilt properly,then get a cheap fuel pump to see if it solves the problem. If it doesn't then you need whoever rebuilt your carb to check it out again or do it yourself. Normally the float level(if adjusted properly) shuts off the needle no matter what the pressure is from the pump.. Here's the fuel system section from the manual that you can check settings on your BST34/40 carbs if you want to do it yourself.https://www.google.com/url?sa=t&rct=...,d.aWw&cad=rja
Plus here's what the pump internals look like.Dirt Cheap Yamaha, Polaris, Suzuki & Kawasaki OEM Parts & Accessories – Cycle Parts Warehouse
Plus always check for any damaged/kinked fuel lines along with the vacuum line from the carb to the fuel pump.
PLUS the BST40 carb is a hard carb to adjust the float level properly without a little dribbling through the overflow! Look at this post on it,shows how to really set one properly..Used on a Ktm,but basically the same carb. http://www.advrider.com/forums/showthread.php?t=347184

 

hmm, welp gonna take apart the pumpand see whats going on in there...thanks opt!

 

Will warn you though,a little drip every now and then from the over flow tube especially at an idle is a common problem on the BST40 carbs,whether it's on a Scrambler or a Sportsman.Hard to stop this even if the float level is set to spec. Pouring out fuel isn't normal though!

 

well i took the pump apart and it was a little dirty but diaphragms looked fine, cleaned it and slapped it back together and at idle it was dripping..it drips a drip like every second maybe even 2 or 3 drips a second...so i turned it of for a minute, started it back up and no drip...its hit or miss

 

The float tab must rest on the small spring pin of the needle with no pressure on it.. At least according to the manual its sets this way,but imo the design if the float itself sucks!I really think some of the problem on carb dripping is that fuel could pass by the seat o-ring into the bowl. The carb bowl is what puts pressure on the seat body and o-ring,holding it down and in place,doesn't screw in or push in and held in place by a plate like the old dependable BST34 carb was.. Try to adjust like this and see if it helps. Shows this setting in the "BST40 bible" post also.