Dong Fang DF 250 RTB Bobber Information

**drgnsghost** · 04-11-2014, 10:13 PM

Hello all! New guy here. New to bikes, not mechanically inclined by any means, fresh motorcycle license, and trying to ride a DF250 RTB with an exhaust pipe that gets so hot it turns cherry red just sitting in idle for 5 minutes. Now that we have that out of the way. :)

I picked up this badboy from a local seller 3 days ago. Bike came with a 2 and half gallon HD tank, but no other mod. Been reading this forum ever since. It's amazing all the common problems and great solutions everyone posts. Hoping someone can point me in the right direction, (also hoping that direction won't be to an exit door). I've tried for several hours to rotate what i believe are the air and fuel mix screws. No matter how i turned them, the idle seems extremely high. I know many have mentioned a leaner idle, but i seem to be having the opposite problem. What worries me the most is how hot the exhaust pipe gets, mainly section immediately coming out of engine nearest to front tire. Can someone help with locating a manual or pointing out the parts from the pictures i've taken so far?

I appreciate any help. Thank you.

20140411_150005.jpg 20140411_150017.jpg 20140411_150038.jpg

**Nick Papageorgio** · 04-11-2014, 10:19 PM

Mine was delivered with an EXTREMELY high idle. Turns out it was the cable adjustment at the throttle grip.

**drgnsghost** · 04-11-2014, 10:27 PM

Thanks Nick
Sorry to reuse same picture.
That's exactly the problem i think i'm having. So I tried adjusting the two nuts that hold the throttle cable. (not sure i'm saying/describing this correctly).
Is there somewhere else i should be adjusting the throttle?

After that i've been messing around with those screws based on my lack of mechanical knowledge and the related problems others have mentioned on this forum.

Also, found this info, but no idea what it means.

note JD630
him - HAVE A HUGE PROBLEM!!!!!!
Filled up the tank and started. Holy s--t full RPM, couldn't get to the kill switch fast enough.
me - pulled the needle seat didnt ya :P
wide open throttle is caused by re-inserting the carb tube (with needle in it) so dont seat fully . I did that myself
look at it the cutout has to be facing the rear wheel , and it will let it seat deeper , stopping that WOT on start

is that what u did ?

him - yes

that solve u problem ? if not idle screw is under moving throttle on carb (side facing out) thru the pivot the cable rides on

20140411_150005.jpg

**Nick Papageorgio** · 04-12-2014, 12:23 AM

Mine was the adjustment up on the twist grip.

**drgnsghost** · 04-12-2014, 12:52 AM

Got it. I'll look into how to get adjust it. Hope this will take care of things for a while.

**drgnsghost** · 04-13-2014, 02:48 AM

Had an afternoon of one step forward and two steps back. Looked into the throttle cable adjustment from the twist grip. No real change there, i ended up leaving the screws in their original location. The step forward was when i realized I wasn't giving the screw on the right side of the carb enough counter clock wise turns. The screw was originally all the way closed, or all the way turned clock wise. When i gave it more counter clock wise turns, the idle wasn't as high and exhaust wasn't turning cherry red anymore. Wasn't long before the muffler was backfiring though. Had some spots of black smoke followed by engine cutting off. I messed with it for at least an additional hour before i called it quits for the day. Was afraid to break the darn thing. I did also set the screw on the front part of carb all the way closed, then gave it two counter clock wise turns to open. Glad i'm not burning up the exhaust anymore, but not sure i'm on the better side of things either.

Additionally, i'm rereading this entire post in hopes of findings answers i missed before. Really wouldn't want to get so discouraged that i end up selling this bike.

**Babyswiss** · 04-13-2014, 09:08 PM

drgnsghost: Not to sound like a jerk, but didn't you test drive or run the bike before you bought it at a dealer? If you just recently picked it up wouldn't they be able or willing to "tune" it in for you?

**barnone** · 04-13-2014, 11:37 PM

Originally Posted by drgnsghost

Hello all! New guy here. New to bikes, not mechanically inclined by any means, fresh motorcycle license, and trying to ride a DF250 RTB with an exhaust pipe that gets so hot it turns cherry red just sitting in idle for 5 minutes. Now that we have that out of the way. :)

I picked up this badboy from a local seller 3 days ago. Bike came with a 2 and half gallon HD tank, but no other mod. Been reading this forum ever since. It's amazing all the common problems and great solutions everyone posts. Hoping someone can point me in the right direction, (also hoping that direction won't be to an exit door). I've tried for several hours to rotate what i believe are the air and fuel mix screws. No matter how i turned them, the idle seems extremely high. I know many have mentioned a leaner idle, but i seem to be having the opposite problem. What worries me the most is how hot the exhaust pipe gets, mainly section immediately coming out of engine nearest to front tire. Can someone help with locating a manual or pointing out the parts from the pictures i've taken so far?

I appreciate any help. Thank you.

20140411_150005.jpg 20140411_150017.jpg 20140411_150038.jpg

Top left is idle speed on carb but as other have mentioned you need some slack in the throttle cable first.

The air mix screw is correct.

Other is the float bowl drain screw.

**barnone** · 04-14-2014, 12:01 AM

Originally Posted by drgnsghost

Had an afternoon of one step forward and two steps back. Looked into the throttle cable adjustment from the twist grip. No real change there, i ended up leaving the screws in their original location. The step forward was when i realized I wasn't giving the screw on the right side of the carb enough counter clock wise turns. The screw was originally all the way closed, or all the way turned clock wise. When i gave it more counter clock wise turns, the idle wasn't as high and exhaust wasn't turning cherry red anymore. Wasn't long before the muffler was backfiring though. Had some spots of black smoke followed by engine cutting off. I messed with it for at least an additional hour before i called it quits for the day. Was afraid to break the darn thing. I did also set the screw on the front part of carb all the way closed, then gave it two counter clock wise turns to open. Glad i'm not burning up the exhaust anymore, but not sure i'm on the better side of things either.

Additionally, i'm rereading this entire post in hopes of findings answers i missed before. Really wouldn't want to get so discouraged that i end up selling this bike.

This should be a minor problem that any decent motorcycle shop should be able to fix in a very little time. The DF is about as simple a bike to work as any. However most shops will not work on Chinese bike like they would not work on Japanese bikes back in the day.

I usually say that a new biker should stay away from a Chinese bike unless they have access to a good dealer shop or an experienced friend that can help them.

As Babyswiss says you should take your DF back to the shop you bought it from and have them correct this problem. Should only take a little time to do it.

Carb info at
http://wem.walbro.com/distributors/s...CAEBURETOR.pdf
The DF has a PZ 30 which is just a bigger version of the PZ 26.

**GonzoX** · 04-14-2014, 03:58 AM

Originally Posted by Nick Papageorgio

Mine was the adjustment up on the twist grip.

Mine was cable catching on my steering shaft. Brother fixed that with a cheap nylon tie down cable that one would use on a trash bag. Go figure, but it worked. Every time I turned left my throttle would go to 100%. Not a good thing to happen in heavy traffic LOL. He was the biker. I only have one year under my belt. so Im learing.