Dong Fang DF 250 RTB Bobber Information

Bobthebobber,
I wired the halo light to be on all the time. About a week or so after installing the halo led headlight, the headlight stop working. Then a week after the halo part went out too. Since then, I haven't troubleshoot the problem. Everything seem fine in the beginning, headlight and halo worked fine. I think (wild guess) that the headlight went out the day I used the honk for the very first time. That's when I noticed I didn't have lights. A week later, I figured I press on the honk again, hoping it will magically trigger the headlight to come back on, but no luck. A day after, I noticed that the halo part was out too. I check the bulb and it looked fine.
I haven't and I am not gonna troubleshoot the problem as I have no knowledge about electrical. Plus I don't have that much time. I think I read somewhere that the headlight are interconnected with the honk wire, think I saw that in the diagram in the manual. Anyways, the way I'm going about this problem was to just order a new wire harness that will be wire to directly to the headlight. This wire hardness comes with the proper relay and resistor. I'm waiting for the harness to arrived from china. After installing the harness I'll let you know how it goes. I'm just hoping it works..........
And that is a badass filter you found... I'm gonna order one to try

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Originally Posted by axa

whats wrong with the setup you have in this pic above?

This is what i do with the stock filter, fixed my top end WOT issue and leaves me a bit of extra air without leaning it out according to the sparkplug.
But yet i still have enough airflow that i can apply a bit of choke with no apparent problems...

Does it give you too much air? The stock filter is apparently restrictive enough to prevent this...

By the way, you'll be able to butt that p-trap right up against the carb and minimize the size of the couple to about an inch, then the rubber black is at a minimum.
That said, the black on our matte bikes don't look so bad
check it out:

Attachment 13241

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did you cut down the longer side of the trap or the shorter side? How much did you take off?

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Originally Posted by Chi town

Bobthebobber,
I wired the halo light to be on all the time. About a week or so after installing the halo led headlight, the headlight stop working. Then a week after the halo part went out too. Since then, I haven't troubleshoot the problem. Everything seem fine in the beginning, headlight and halo worked fine. I think (wild guess) that the headlight went out the day I used the honk for the very first time. That's when I noticed I didn't have lights. A week later, I figured I press on the honk again, hoping it will magically trigger the headlight to come back on, but no luck. A day after, I noticed that the halo part was out too. I check the bulb and it looked fine.
I haven't and I am not gonna troubleshoot the problem as I have no knowledge about electrical. Plus I don't have that much time. I think I read somewhere that the headlight are interconnected with the honk wire, think I saw that in the diagram in the manual. Anyways, the way I'm going about this problem was to just order a new wire harness that will be wire to directly to the headlight. This wire hardness comes with the proper relay and resistor. I'm waiting for the harness to arrived from china. After installing the harness I'll let you know how it goes. I'm just hoping it works..........
And that is a badass filter you found... I'm gonna order one to try

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Thanks my light came in the mail today. For those with the stock light I found an easy method to be able to see at night. Put your light in lowbeam. Then hold down the "flash switch." While you are holding it down, put a small finishing nail or screw in behind it in the space that opens when it is pressed. This will now allow the switch to release and it will remain on until you pull the screw or nail out... this is a good fast method so you can see better at night.. and not have to rewire anything.

I will attempt this new light tomorrow and see what happens. Chi where did you order the harness from?

I also noticed today that my rear sprocket does not seem to be true. It seems to be warpped and I can see this very clearly when I look down at it while riding. The tire is aligned perfect using a scientific ruler on the axle bolts... maybe my rim is bent.. also the front rim doesnt seem to be 100% true either but it rides fine. The rear might be an issue though... Ill have to mess with it

Quote:

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Originally Posted by Bobthebobber

did you cut down the longer side of the trap or the shorter side? How much did you take off?

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The longer side, making it more symmetric. about an inch or so. eyeball it.
Otherwise i found when you mount it, using the only end that would fit in between the carb and frame, it left the filter end too close to the engine fins. personal preference i suppose.

Bob the bobber,
Here's the site that I ordered from.
http://www.sourcingmap.com/car-motor...-p-283757.html
I'm not even sure if this will solve my headlight problem as I don't know what caused the light to go out. I just figure this way is cheaper and easier for me instead of trying to troubleshoot the problem. I figure if its the relay that is blown, upgrading to a bigger relay will require new socket anyways. so to save me time, I find it easier to just add a new harness with the correct relay and resistor for the h4 bulb.

If you increased the wattage of the headlight,their is a good chance you smoked the handlebar switch(with its tiny wires).
I do not think the Dong Fang uses a headlight relay from the factory.

This is the proper way (if your electric system can supply it) to get large wattage feed to the headlight :Wiring Kits

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Originally Posted by Bobthebobber

I also noticed today that my rear sprocket does not seem to be true. It seems to be warpped and I can see this very clearly when I look down at it while riding. The tire is aligned perfect using a scientific ruler on the axle bolts... maybe my rim is bent.. also the front rim doesnt seem to be 100% true either but it rides fine. The rear might be an issue though... Ill have to mess with it

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Attachment 13242

You could put the wheel in one of the truing/balancing stands like mine from Harbor Freight to see what is out of alignment. You could also just build the stand out of wood to do the test.
Move the straw to check sprocket and wheel run out.
Both the wheels on my DF tested true but needed a little balancing. My Ural wheels were out of alignment but a spoke torque wrench trued them up easy peasy.

o.k. folks, I am having a bit of an issue with these cush bushings. If anyone can assist it would be great. The two part numbers I have found so far are 41241-KB4-003 and 41241-307-010 . trouble is i do not know which is correct or if either one is correct. They both seem to use the same wheel bolts 90128-382-670 but it is the size themselves i am having a problem making sure they are correct. I hate to be a bother with anyone about this, but if anyone can run it around and come up with something please let me know. Thanks.

well i pulled the trigger on the cush bushings ,lets hope they are correct. i purchased 41241-307-010. will keep you posted.

How much different are the Dongfang RTB and RTC engine and transmission wise, and/or gear/sprocket wise?

And what about performance comparisons?

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Originally Posted by bowtiewagon

well i pulled the trigger on the cush bushings ,lets hope they are correct. i purchased 41241-307-010. will keep you posted.

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Think you mentioned visiting a honda dealer...
Would they not pull the honda part so you could measure it against yours?
Did they not have it in stock?

Only trouble is ur the first to 10k and and i bet the first to need a drive bushing swap

Don't forget to post the winning part #...

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Originally Posted by ProDigit

How much different are the Dongfang RTB and RTC engine and transmission wise, and/or gear/sprocket wise?

And what about performance comparisons?

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They are the same.All the mod info is in this thread.

I drilled out the cat tonight..it looked to be more of an aluminum baffle than catalyst material.

I went to lowes and bought a 1 inch bi-carb hole saw.. the deepest one i could find.. and two 10 inch extensions and attached them together..

It took me about an hour.. because the drill bit fell off the extension and got stuck in the pipe... (silly me for not tightening down the set screw enough)

It was pretty diffiuclt because the holesaw bit was not deep enough.. even though it was the longest one.. so you really have to keep working at it from different angles until you can grind it all out. It seems where the exhaust comes in from the inside of the pipe... it runs out of a tiny 1 inch pipe as you can see way down at the end in the picture... the outside of this pipe is quite deceiving..

Anyway the sound is the same.. no real changes.. seems to pop a little more... which I like anyway.. but I didnt ride it much.. ill keep you updated.

I have not attached my ram air pipe yet.

http://i924.photobucket.com/albums/a...ps3f9f928f.jpg

Quote:

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Originally Posted by Bobthebobber

I drilled out the cat tonight..it looked to be more of an aluminum baffle than catalyst material.

I went to lowes and bought a 1 inch bi-carb hole saw.. the deepest one i could find.. and two 10 inch extensions and attached them together..

It took me about an hour.. because the drill bit fell off the extension and got stuck in the pipe... (silly me for not tightening down the set screw enough)

It was pretty diffiuclt because the holesaw bit was not deep enough.. even though it was the longest one.. so you really have to keep working at it from different angles until you can grind it all out. It seems where the exhaust comes in from the inside of the pipe... it runs out of a tiny 1 inch pipe as you can see way down at the end in the picture... the outside of this pipe is quite deceiving..

Anyway the sound is the same.. no real changes.. seems to pop a little more... which I like anyway.. but I didnt ride it much.. ill keep you updated.

I have not attached my ram air pipe yet.

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I too had a hell of a time drilling out the cat for similar reasons.

Also I didn't notice a hell of alot after drilling out the cat, but that might be because just the day before i installed the reverse ram which solved the top end WOT sputter by itself.

Since you didn't install the reverse ram yet, it would be interesting to know if just drilling out the cat by itself will allow enough airflow to stop the top end WOT sputter.
Or did you deal with that issue already?

And I didn't really notice the exhaust being any hotter before, or cooler after...

Are there true 250cc BBK kits for this 229cc engine? Or is the engine on itself a 200cc engine with 229cc BBK?

Quote:

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Originally Posted by axa

I too had a hell of a time drilling out the cat for similar reasons.

Also I didn't notice a hell of alot after drilling out the cat, but that might be because just the day before i installed the reverse ram which solved the top end WOT sputter by itself.

Since you didn't install the reverse ram yet, it would be interesting to know if just drilling out the cat by itself will allow enough airflow to stop the top end WOT sputter.
Or did you deal with that issue already?

And I didn't really notice the exhaust being any hotter before, or cooler after...

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My top end sputter already sorted itself out prior to the exhaust. With a motor this small though.. every little thing helps

I waxed my exhaust to make it shine. The spot on the pipe where the "cat" was would always just turn dull again.. Ill rewax it tomorrow and see if it keeps a shine now.. that will be a good indicator if that "hot spot/shoe melter" is gone

I did test the exhaust pipe with my infrared thermometer and the area where the catalytic converter was definitely hotter. That is why your auto's cat has a heat shield.

All these mods we make to our 229cc motors probably help some but none are that big of an improvement.
The best I got out of my 2010 DF was 68 MPH GPS. I'm at 65 MPH indicated with my 2012 DF now.

"Change your CG250 67mm air cooled engine (167FMM)to 70mm bore,Kit include piston kit and gasket" at
http://www.chinese-parts-canada.com/...bore_kits.html
might help some but I don't know if it is worth the money.

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Originally Posted by ProDigit

Are there true 250cc BBK kits for this 229cc engine? Or is the engine on itself a 200cc engine with 229cc BBK?

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its a Honda clone CG 125 big bore kitted to the 229 , U might try measuring a Honda 250 motor to see if a direct swap is doable , ive been meaning to but every time I start to get to that point life punches me squarely in the wallet

From a 125 to a 229??? Are you sure that's right?
That'll be 80+% more displacement; those engines will be worn out in no time, and no wonder they vibrate so much!
I doubt that the counter balance is made to handle those extra cc's !

Is there something simple that can be done to reduce vibrations?

I rather have a 250cc with a 229cc small bore kit (if that existed), than having a 125cc engine with a 229cc bbk.

The MC-05-127 I have now, with a step through semi-manual gearbox, is a 110cc engine with an extra 17cc's, and it's pulling the clutch to where it slips.

Combination of cat removal and ram air yields no noticeable improvements

http://i924.photobucket.com/albums/a...ps2d2c0fed.jpg

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Originally Posted by Bobthebobber

Combination of cat removal and ram air yields no noticeable improvements

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Interesting, but i bet you can apply a bit of choke at speed with no impact...
If so, I would then postulate that you can bump your main jet up quite a bit, and them maybe even your needle
Try it, it's the last step in this evolution

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Originally Posted by DanDaMan

its a Honda clone CG 125 big bore kitted to the 229 , U might try measuring a Honda 250 motor to see if a direct swap is doable , ive been meaning to but every time I start to get to that point life punches me squarely in the wallet

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I think a Honda Rebel 234cc engine would be doable. The engine mounts might have to be fabricated and dual exhaust. Drive gear should be OK.

Another use for the DF engine... http://www.theblackdouglas.co.uk/

bob r u stock geared ? if so I bet your rpm limited , nope I c your running the 35 , hmm

get running 90% full throttle top gear hit engine cutoff switch , roll to side of road pull and look at sparkplug tip , your shooting for tan , if its white or black u need to jet

Quote:

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Originally Posted by axa

Think you mentioned visiting a honda dealer...
Would they not pull the honda part so you could measure it against yours?
Did they not have it in stock?

Only trouble is ur the first to 10k and and i bet the first to need a drive bushing swap

Don't forget to post the winning part #...

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I called two dealers around town, both told me thye had to order them and then if they were not the right ones, 15% restock fee. I found a set of them online with diminesions, and went out and measured mine. Same O.D. for the one part number, the other two were smaller O.D. so I went with the 41241-307-010. once here will keep you posted.

Quote:

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Originally Posted by DanDaMan

bob r u stock geared ? if so I bet your rpm limited , nope I c your running the 35 , hmm

get running 90% full throttle top gear hit engine cutoff switch , roll to side of road pull and look at sparkplug tip , your shooting for tan , if its white or black u need to jet

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You could also test with the choke. If the choke is a slider you can set the choke at the perfect A/F mixture. If it is a switch, it's less of a possibility. But with the choke you can find the sweet spot of the AF mixture, and ride on it like that.

I currently do it on my MC-05-127, which has a choke lever on the left on the handlebar.
By sometimes cutting some air, performance increases (true, upjetting, and your performance increases even more; until you upjet too much from the ideal mixture).

The ideal mixture is slightly lean (with slight pops on the exhaust at decel).

I've enjoyed my Bobber for the past 2 years and was out with a friend enjoying the Natchez Trace when I heard a mechanical clank and my engine shut down. After a 3 hour wait on the road for my friend to get her truck to bring me home, I pulled the spark plug. To my suprise the sparkplug tip is damaged. I haven't pulled the cylinder head yet, but I'd like to know if anybody has found a parts supplier for the engine before I try to tear it down.

Per requests, here are photos of the spark plug. It's an NGK plug I had replaced for the original plug.
Attachment 13262Attachment 13263

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Originally Posted by 85highwall

I've enjoyed my Bobber for the past 2 years and was out with a friend enjoying the Natchez Trace when I heard a mechanical clank and my engine shut down. After a 3 hour wait on the road for my friend to get her truck to bring me home, I pulled the spark plug. To my suprise the sparkplug tip is damaged. I haven't pulled the cylinder head yet, but I'd like to know if anybody has found a parts supplier for the engine before I try to tear it down.

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please do us a favor and take a nice clear picture of your spark plug tip and post it here.

it would go a long way in schooling many of us if the damage was due to poor running conditions/neglect/bad jetting, or just the fat chance your spark plug just fell apart and jambed itself in the mechanisms.

was it the original spark plug?
or was it changed at some point? when?

There will be follow up question from a few of us for sure, but before the speculation starts, I hope to get the true story from the source.
thanks

Quote:

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Originally Posted by 85highwall

I've enjoyed my Bobber for the past 2 years and was out with a friend enjoying the Natchez Trace when I heard a mechanical clank and my engine shut down. After a 3 hour wait on the road for my friend to get her truck to bring me home, I pulled the spark plug. To my suprise the sparkplug tip is damaged. I haven't pulled the cylinder head yet, but I'd like to know if anybody has found a parts supplier for the engine before I try to tear it down.

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You might try this place out http://www.chinesemotoparts.com/inde...094246275aad57

Here is another http://www.ebay.com/itm/New-Zongshen...-/250654515200