I'm working on a 2007 Polaris 330 2x2 for my Boss he is the original owner

Symptoms
engine will only idle with a bit of choke, when I close the choke the engine will start to die. I can however keep it running, but with some throttle movement, but if I give it WOT the rpms start to drop off, and the engine will quit, then fart! through the carb. I can restart it, but only either giving throttle or opening the choke some, but it will run just not as it should. It has little to no power when trying to move it

I pulled the plug, and it is blackish, possibly a rich fuel condition

The gas is fresh, fuel pump is working...

I would appreciate any direction in finding the issue with this ATV.

In my experiences over the years with a rich condition, points to a fuel float, needle possibly bad, needle seat worn out...maybe I forgot something...

thanks for any help

 

I'd install a new carb kit rather than just tearing one apart and trying to clean one. Having to have the choke on is usually a tell tale sign of either a pilot jet stopped up or a needle and seat sticking because of trash,bits of deteriorated fuel hose blocking up things. Plus no sense in having to go back in again if cleaning it doesn't help.http://www.ebay.com/itm/CARB-REBUILD-KIT-POLARIS-TRAILBOSS-330-2003-2004-2005-2006-2007-REPAIR-2X4-2WD-/270462316796?pt=Motors_ATV_Parts_Accessories&hash=item3ef8cf70fc&vxp=mtr

 

I agree OPT...I will get him to order the kit, thanks!

 

OPT
the link you provided is the kit that needs to be ordered for this 07 Polaris Trailboss 330? gust want to double check

and is there any other things I need to check? how about the ignition pickup coil at the flywheel, any instructions on how to check the air gap?
When the pull rope broke last time it bent back the ignition pickup coil, and the engine wouldn't fire using the electric starter. I replaced the rope again and just set the air gap using a piece of parts box, like I do when I work on small engines.

what about the fuel pump?
thanks for any help

 

Kits fits 2003-2007 models from the description. Have around .040 clearance between the face of the pick up coil and the raised portion on the flywheel. Just pull the fuel line off the carb and crank the engine over,fuel should pulse through the line.

 

thanks for the info...I'll post back my findings once I get my boss to order that kit

 

Okay, I got the carb removed. It is a MIKUNI 32F10C E6Z2 Is this called a MIKUNI 32mm? cause if it is, google don't bring it up..

thanks for the help I appreciate it
here is a couple of pics of it

 

This is just part of the serial number or series,but the carb is a BST34 Mikuni. This carb was used on the 4 stroke 325,330,400,425 and early 500 engines. Later model 500,600/700 models used the BST40. Plus here's a pdf section on this carb from the service manual that can help with rebuilding it.http://www.google.com/url?sa=t&rct=j...,d.aWw&cad=rja

 

I don't know how you do it OPT, seem to have all the right info, and answers..thanks! This will help me more than you know...

 

Thanks for the help!