Dong Fang DF 250 RTB Bobber Information

[Bobthebobber]

Combination of cat removal and ram air yields no noticeable improvements

[axa]

Combination of cat removal and ram air yields no noticeable improvements

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

[SR.MAILMAN]

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

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/

[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

[bowtiewagon]

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 #...

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.

[ProDigit]

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

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).

[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.

Per requests, here are photos of the spark plug. It's an NGK plug I had replaced for the original plug.
DSCN0593.jpgDSCN0594.jpg

[axa]

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.

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

[Bob form NV]

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.

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

[Bob form NV]

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