Dong Fang DF 250 RTB Bobber Information

**4950cycle** · 09-22-2013, 03:41 AM

axa, I find my shifter a bit bulky too. And quit capitulating. Your getting it all over the carpet .

**4950cycle** · 09-22-2013, 04:00 AM

And Barnone, This is kinda weird. I have the same miles on my bobber as you do. And just finished putting two 4 inch baffles welded together in exhaust pipe. I bought the two 4 inch versions of your one. I was thinking if I got the big one it would rob power or be to quiet. I was wrong the 4 incher did very little. So I cut the bell off the other 4 incher and welded it to the end of the other unmolested 4 inch baffle with my Harbor freight sputter bug. It made about a 7-8 inch baffle that took enough of the bark out of the exhaust note. And just like you again, I noticed almost no power loss. Maybe,maybe a pinch of midrange ? But relatively neglegable considering the less obnocksious ride

**axa** · 09-22-2013, 11:13 AM

Originally Posted by Bobthebobber

Took a ride down to one of the local parks here in RI with a beach front today. Enjoyed the nice weather for sure. She has about 380 miles now.

Funny story... There was a guy in a smart car revving his engine at me at a red light. I thought this was pretty funny.. so I actually just full throttle shifted through the first 4 gears.. until I looked over and he was about 100 feet in front of me...

In case you didn't know.. the Smart-car is the slowest accelerating car available in America as of 2012... not good not good lol. I love this bike.. but man it's embarrassing when people are honking at you for only being able to do 40 miles an hour up an incline on a 50 mph road lol. Today on my ride I had to pull off to the right of the road and turn my flashers on and allow cars to pass.. as the limit goes up to 55 on about a 1 mile stretch of hill... I wont be going that way again.. good thing I had a bandanna over my face.. because it was beat red :p

That's not a funny story, its turning out to be a tragedy that is played over and over again.
I feel your pain bro. I intentionally avoid roads like this.

This engine is coming out, one way or another, its just a matter of time.

**barnone** · 09-22-2013, 03:28 PM

Originally Posted by axa

This engine is coming out, one way or another, its just a matter of time.

That CG350 you found is looking good but at 2400 Turkish Lira ($1100 USD) it is kinda steep. We need to find the manufacturer of that engine, I bet it is Chinese.

**Bobthebobber** · 09-22-2013, 11:42 PM

Originally Posted by barnone

That CG350 you found is looking good but at 2400 Turkish Lira ($1100 USD) it is kinda steep. We need to find the manufacturer of that engine, I bet it is Chinese.

]

find a used honda XL250 motor. Its the same as the older honda xr250 motors but it's preset for electrical.. as the xl250 was a dual sport dirtbike.

my old xr250 could cruise upwards of 80 mph with stock gearing and a 20 year old motor with nothing but oil changes for maintenance.

If i remember correctly the engine was a 4 valve and put out around 25 hp at the wheel. The XL250 was a BIG deal when it first came out in the late 70's. I actually saw one on the freeway a few weeks ago doing about 75-80 mph in the high speed lane.

**Bobthebobber** · 09-23-2013, 12:11 AM

Originally Posted by Bobthebobber

]

find a used honda XL250 motor. Its the same as the older honda xr250 motors but it's preset for electrical.. as the xl250 was a dual sport dirtbike.

my old xr250 could cruise upwards of 80 mph with stock gearing and a 20 year old motor with nothing but oil changes for maintenance.

If i remember correctly the engine was a 4 valve and put out around 25 hp at the wheel. The XL250 was a BIG deal when it first came out in the late 70's. I actually saw one on the freeway a few weeks ago doing about 75-80 mph in the high speed lane.

Some of the Xl's came with a 6 speed tranny also.. since it was used on the road and not just the dirt. I think my xr250 had a 48 tooth rear (not sure what the front was) and I was able to do over 80. So if we tuned that motor for the street and put on say a 35 or 40 tooth.. you could do 90 possibly on a flat road.

**ProDigit** · 09-23-2013, 12:35 AM

To see 90MPH out of a 250cc could only happen if it's a short throw parallel twin engine (or more) with a red line on the 11k RPMs.

Ain't no way a regular 250 can pull 90! Heck, my 750 only pulls 103MPH, and that's 3x the displacement!

**Bobthebobber** · 09-23-2013, 03:12 AM

Originally Posted by ProDigit

To see 90MPH out of a 250cc could only happen if it's a short throw parallel twin engine (or more) with a red line on the 11k RPMs.

Ain't no way a regular 250 can pull 90! Heck, my 750 only pulls 103MPH, and that's 3x the displacement!

my 87 xr250 did 87-88mph gps confirmed

my 89 ninja250 did 120

and its not always about displacement.. I had a pocket bike that was registered and i would commute to work with it on the freeway.