Dong Fang DF 250 RTB Bobber Information

**igouge** · 10-21-2013, 07:01 PM

Originally Posted by GonzoX

This may have been answered but you could do what I did. Take the part number right off the DF schemattic, even with the chinese symbols and paste them into google search and you might be surprised at what you will find. I got a new exact replacement oil dip stick this way and even the seller said it was NOT for my bike, it was for a Honda LOL. They tried to talk me out of the purchase but it was an exact replacement.

Just food for thought.

OK, will do. -and ditto on the Honda parts, the engine is a near exact clone of a Honda CG125 with a larger jug and head. The sprockets are Honda Rebel (dimensions) and the rest of the bike looks like off-the shelf generic stuff I see on all the other Chinese bikes that cross reference many different models. I have a CCW Heist as well, and already did my homework on mechanical parts availability when I got that previous to the DF. Anyone notice that the DF container that holds all the electronics is actually an air filter housing for some other vehicle (hense the two large hose fittings/clamps?).

**igouge** · 10-21-2013, 07:03 PM

I know this is an odd question...but do we really believe this bike is 420lbs dry weight? I only ask since that what all the sites list it as, and yet Tha Heist weighs in at only 253lbs? A 167lb diff on a 250cc bike is huge! I'm looking at both of them side by side and tho the Heist is a tad lower in profile and a few inches shorter...I can't see that much weight difference between the two. I'm not comparing for the sake of comparing - my intention is to take one of these bikes and convert it to a flat track / board track racer and since I'm gonna ditch one of the frames I'd rather it be the heavier of the two... 420lbs can't be right...

**barnone** · 10-21-2013, 08:27 PM

Originally Posted by igouge

I know this is an odd question...but do we really believe this bike is 420lbs dry weight? I only ask since that what all the sites list it as, and yet Tha Heist weighs in at only 253lbs? A 167lb diff on a 250cc bike is huge! I'm looking at both of them side by side and tho the Heist is a tad lower in profile and a few inches shorter...I can't see that much weight difference between the two. I'm not comparing for the sake of comparing - my intention is to take one of these bikes and convert it to a flat track / board track racer and since I'm gonna ditch one of the frames I'd rather it be the heavier of the two... 420lbs can't be right...

I would not pay much attention to the drop shippers information on the DF nor would I pay much attention to the information from CCW. They still claim the 167fmm to be 250 cc.
The DF should weight about the same as the Heist. Have you weighed your Heist?

EDIT: I just weighed my DF with a digital bathroom scale weighting one wheel at a time and got the following:
front end 139 lbs
rear end 157 lbs
total 296 lbs
less 2 gals of gas 16 lbs, larger seat maybe 3 lbs, and top box and rear rack approx 15 lbs
So dry weight with oil but no gas of a stock 2012 DF is approximately 270 lbs.

Weight your Heist and also your DF and check my values.

**ben2go** · 10-22-2013, 12:00 AM

My GS5 weighs in at 425lbs dry and I have added weight to it with modifications,so knew the DF was a lot less.Thanks for the confirmation Vince.

**barnone** · 10-22-2013, 01:10 AM

Originally Posted by ben2go

My GS5 weighs in at 425lbs dry and I have added weight to it with modifications,so knew the DF was a lot less.Thanks for the confirmation Vince.

Remember that I was using a bathroom scale so my number can be off a bit.

I was looking at the specs from some of the drop shippers and noticed 17 HP at 8,000 RPM. I wish.
One has the fuel at 3.8 gallons and another at 1.8 gallons. I put 2 gallons in the empty tank of my 2012 DF.
What a bunch of bozos the drop shippers are.

I weighed my Ural at the rock pit and it was 940 lbs. I do have quit a bit of stuff in the trunk but still...
I also weighed myself at the rock pit and came in at 220 lbs so it is right on. Maybe I'll stop there tomorrow and weigh the DF to verify the weight.

**axa** · 10-23-2013, 11:50 PM

Just got back from biz trip to japan. boy was i itching to jump a plane to shanghai and bring a new engine back with me...
Well now i feel its just to cool in the North East to ride. I feel robbed of the end of the riding season.

I did get to pick up a variety 5 pack of genuine keihin jets from 105 to 120 and a 45 pilot for just a few bucks in one of the many Ueno bike places.
They were out of 42 which brings me to this question, why do we upgrade theses pilots, even in the summer i find 2 or 2.5 turns on the mix leaves me rich enough at idle.
I dont suspect it getting any worse in the winter...
Do you guys live further north? or in the mountains? i just dont see the need.
if anything i should turn in my mix screw to help prevent the stall on acceleration.

So I guess the head work can soon start.
i 'polished' my nasty intake manifold to a nice sleek finish and put it back between carb and head.
Also 'ported' the stock air filter, pulled it apart, ripped off the joining rubber grommet, cut it open and to 38mm.
After it dries i see if i can take off a bit more, the intake itself is 42mm so...
You will see it is reduced the way it currently joined together, and not very aerodynamic.

Then just watched the bike idle while PMS begins to set in.

**barnone** · 10-24-2013, 12:26 AM

axa,
And the head work is?
Did you take a photo of your "nasty intake manifold to a nice sleek finish" ?

**axa** · 10-24-2013, 03:13 AM

Originally Posted by barnone

axa,
And the head work is?
Did you take a photo of your "nasty intake manifold to a nice sleek finish" ?

and i thought i was bogarting this thread with my plans...
here are a couple of the links

http://www.mychinamoto.com/forums/sh...ll=1#post64034

http://www.mychinamoto.com/forums/sh...ll=1#post64034

well i suppose i can summarize it for you.
- clean up the intake, i saw sand and split casting marks.
- polish the exhaust, easy enough. open the port match the exhaust, replace the paper coil exhaust gasket with one new appropriate size.
- power ringz the valves as linked above.
- increase comp ratio, hone/deck head as needed. believe i wrote about my process already
- hone the cylinder, if/as needed.

then rejet with my new keihins as needed

all while still looking for a new engine..

ya i posted the bumpy intake already, that pic really doesnt do justice. it must have reduced the diameter at that point a mm or so. post the new later.

dont get me wrong, i dont really believe all this will do much of anything, but i find it interesting. id like to prove what it won't do, cuz if one read the heist thread, they would think these bikes will do 90 after the secret mystical 'weaver' mods.

**axa** · 10-25-2013, 06:56 AM

so i went to rejet today... it turns out my report of recent lean running, needing to close off the choke about 25%, was due to a partially clogged main jet.
This happened right when i drilled out and tapped the carb directly to the head, so at first I wrongly concluded removing the intake manifold must have been allowing extra air, but that didn't explain the lack of power.
So after 'polishing' the manifold smooth i put it back and the problem persisted.
Had to be a gas supply issue and it was.
Lesson learned. check the obvious first, but it was just a nasty coincidence after doing the carb work.

anyway, running a 115 jet now, curious to see how that goes... i did enlarge the stock filter port, smoothed the manifold, lets see if the autumn air can compensate

**barnone** · 10-28-2013, 09:25 PM

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I put this cross up because there are a lot of crashes at this place. A guy hit the tree next to the cross several weeks ago and he died. The orange paint on the tree was painted by NC Highway Patrol as part of the crash investigation.