Dong Fang 250 RTD

[Postigo]

http://https://www.dropbox.com/sh/rs...VK4lf_VCa?dl=0
Hi, I’m the new owner of a DF250RTD.I did the catalytic converter delete, did the jetting with a 105 main leaving the 40 pilot jet and factory sprockets (17X38)
I’m having a hard time going past 66mph and also not able to reach more that 6,500 rpm’s. I have read that some of you with similar setup are able to reach 75 plus.
I think my problems can be related to factory fuel filter and/or factory air filter. Any suggestions will be greatly appreciated. Here is a link with some pics of the motorcycle and air filter setup.

[TominMO]

For sure a factory filter, or more accurately a factory airbox, could be holding you back. Usually it's the airbox intake that is the first thing to open up. The pleated paper filter unit itself is probably less of a restriction. They typically have a lot more air flow capability than the diameter of the intake on the carb or throttle body itself allows.

Can you mod the airbox cover in some way to increase flow? Either by cutting or drilling holes.

Also of course check that you have a clean fuel filter. Back when I had carby cars, I always carried a spare fuel filter and the few tools needed to change it out. Saved my butt a couple of times, on road trips between cities no less.

[Postigo]

Originally Posted by TominMO

For sure a factory filter, or more accurately a factory airbox, could be holding you back. Usually it's the airbox intake that is the first thing to open up. The pleated paper filter unit itself is probably less of a restriction. They typically have a lot more air flow capability than the diameter of the intake on the carb or throttle body itself allows.

Can you mod the airbox cover in some way to increase flow? Either by cutting or drilling holes.

Also of course check that you have a clean fuel filter. Back when I had carby cars, I always carried a spare fuel filter and the few tools needed to change it out. Saved my butt a couple of times, on road trips between cities no less.

I will try to modify the air box and I will definitely remove the fuel filter. Thanks