Re: Dong Fang DF 250 RTB Bobber Information
Thanks to Gardo and Barnone for keeping us informed of their adventures with this Dong Fang bobber, sounds like a good bike for the price. I like the less raked out front end and the seat looks like it's right off of an old BMW R27, very unique looks. I'm looking for a replacement for my ancient 2stroke scrambler, I'll be watching the Dong Fang with much interest!:thumbsup:
Re: Dong Fang DF 250 RTB Bobber Information
Gordo,
The popping is from a too lean condition which is a common problem with EPA bikes.
From post #168
Results: The bike pulls better and revs higher. Was stumbling at high RPM before change.
Stock main is a 88. I used a 100 for the first try. Also have a 105 and a 110 maybe to try.
Stock pilot (low speed) is a 40.
Jets from http://www.jetsrus.com/a_jets_by_car...4-36_main.html
Also I installed two washers under the needle that helps the mid range.
Three washers were too much.
Bike pulls much better now and almost no popping.
Still waiting for the 14 tooth front sprocket which should fix the getting across the intersection without shifting to second gear issue. If the sprocket is too big then smaller rear is the cure as suggested by Aboshi.
The above is about what I had to do to my other bikes to solve the lean and gearing issues.
Re: Dong Fang DF 250 RTB Bobber Information
Here are a fe more things I am going to order today.
set of 10 jets http://cgi.ebay.com/ebaymotors/ws/eB...#ht_2600wt_935
Also you guys might want to get a new CDI to hep with the mid/top end:
http://cgi.ebay.com/ebaymotors/Racin...#ht_1358wt_897
or
http://cgi.ebay.com/ebaymotors/Racin...#ht_1358wt_897
Also you should remove the crap sparkplug it came with and go get a NGK
It sounds like we should have a 105-110 main jet in there, but might not if the CDI and NGK help out.
I was also thinking of a better coil as well, either one of the cheap chinese ones on ebay or a very good one from http://www.nologyhotwires.com/
from nology search for 152-001-060T we would need the single spark plug wire one for $69.99
Im not sure if the chinese coils would be any better then the stock on that comes with the bike to begin with, so I would say stick with nology if your going to do this upgrade. I also found twin tec coild pretty cheap http://www.jpcycles.com/product/382-...utm_medium=cse
All single fire coils should work for any of these single cylinder clones. And I'm sure it would be a very big improvement in the performance for these engines when using the aftermarket CDI.
Re: Dong Fang DF 250 RTB Bobber Information
Quote:
Originally Posted by
Aboshi
Aboshi,
Good stuff on tuning.
I swapped out the plug back when I got the bike for a NGK.
Do you have access to a dyno for tuning? I would like to see what each change does as far as rear wheel HP improvements.
How did you come up with the 105 or 110 main jet? I am currently running a 100 over the stock 88 and it took out the stumbling at high RPM. I have a 105 and 110 that I could try. I really ought to take the bike over to a local shop that has a dyno to try out these changes.
Think I will order the CDI after I check the one on the bike and compare the plugs.
Thanks
Re: Dong Fang DF 250 RTB Bobber Information
I can ask a friend to see if he will let me use the one at the shop he works at on the weekends but I wouldn't hold my breath. If I was down in FL it would be a different story...
As for the jetting if your stumbling is gone with the 100 then you should be fine.
Every motor will react different when it comes to jetting, especially with temperature/altitude/humidity
I forgot to ask a while ago about the transmission on these bikes.
Is is 1 down 4 up or is it 5 down like on most china clones?
I ask because I cant stand the 5 down shifting It confuses the hell out of me and just doesn't feel right what so ever.
Re: Dong Fang DF 250 RTB Bobber Information
Trans is 1 down and then 4 up.
Re: Dong Fang DF 250 RTB Bobber Information
That makes me very happy!
I have to call countyimports today and see if they have my tracking #
Their email server sux badly and I get the emails a day or two later, and trying to contact them I am on hold for 20-40 mins...
I placed the order on the 3rd so I should have heard something by now as far as tracking because I saw they charged my card a few days ago.
Re: Dong Fang DF 250 RTB Bobber Information
Aboshi - how did it go any tracking info yet?
Re: Dong Fang DF 250 RTB Bobber Information
Hi, I am just joining today after reading this thread. I am very serious about trying to get this bobber. I need to sell my snowmobile and trailer first though. This will be my first bike and I am really only getting one for the gas mileage and cruising here and there. Has anybody got it up to 55, and what to get for mileage doing cruising. Thanks, anyone want a snowmobile and trailer lol.
Re: Dong Fang DF 250 RTB Bobber Information
Quote:
Originally Posted by
bckcntryslddr
Hi, I am just joining today after reading this thread. I am very serious about trying to get this bobber. I need to sell my snowmobile and trailer first though. This will be my first bike and I am really only getting one for the gas mileage and cruising here and there. Has anybody got it up to 55, and what to get for mileage doing cruising. Thanks, anyone want a snowmobile and trailer lol.
bckcntryclddr welcome to the boards - tell us a bit about yourself.
barnone could probably give a better estimate on the gas mileage.
I would suggest checking out your local DMV website about registering a vehicle with an MSO/MCO, since you are in NH the live free or die state it may be easier than NJ, the live under our bureaucracy and drown state.
Again welcome aboard and where were you in Dec 2010 when we were buried under 30 inches of snow LOL