Re: Dong Fang DF 250 RTB Bobber Information
Quote:
Originally Posted by
barnone
What kind of MPG are you getting?
Not sure what my mpg is, but Im going to be able to begin to make observations on it now that i don't need to let it sit and run idle.
but thats a number with limited use until we know typically how far into a tank the petcock is.
that said, I forgot to calculate the return trip back from last fill up, so my number is about 105 indicated until a refill is needed.
I drive in limited suburban traffic with very little sitting and moderate amount of stop and go. but that's all very subjective.
Re: Dong Fang DF 250 RTB Bobber Information
I pay 3 bucks for gas , drive 37 miles turn around n ride back n have a bit more gas than I started with , all highway miles cruising at about 5000-5300 rpm 70 mph or so indicated
its basically a "neat looking" moped
2 Attachment(s)
Re: Dong Fang DF 250 RTB Bobber Information
Quote:
Originally Posted by
axa
Not sure what my mpg is, but Im going to be able to begin to make observations on it now that i don't need to let it sit and run idle.
but thats a number with limited use until we know typically how far into a tank the petcock is.
that said, I forgot to calculate the return trip back from last fill up, so my number is about 105 indicated until a refill is needed.
I drive in limited suburban traffic with very little sitting and moderate amount of stop and go. but that's all very subjective.
axa,
Normally the "reserve" position on the petcock on a motorcycle does not have much of a tube sticking up in the tank like the "on" position has so you should be able to use almost all the fuel in the tank.
Attachment 13070
Photo of a typical petcock showing the "on" position's long tube and the "reserve" position's lack of a tube.
This one is a vacuum operated petcock but the manual ones like the DF's have a similar setup for the fuel inlets.
I have not had the petcock out of the 2012 DF tank but every other one that I have out on many bikes including my long gone 2010 DF did not have much of a tube sticking up for the "reserve" position. Usually just a bit in order to attach a filter sock on it.
When she sputters (the petcock is in the "on " position) I switch to the "reserve" position and get gas at the first available station. Of course if I am in an area where I don't know where the gas stations are located then I fill up sooner.
Also as a rule, I do not cut it close on gas in any of my vehicles.
Manual petcock below.
Re: Dong Fang DF 250 RTB Bobber Information
Quote:
Originally Posted by
barnone
axa,
Normally the "reserve" position on the petcock on a motorcycle does not have much of a tube sticking up in the tank like the "on" position has so you should be able to use almost all the fuel in the tank.
Photo of a typical petcock showing the "on" position's long tube and the "reserve" position's lack of a tube.
This one is a vacuum operated petcock but the manual ones like the DF's have a similar setup for the fuel inlets.
I have not had the petcock out of the 2012 DF tank but every other one that I have out on many bikes including my long gone 2010 DF did not have much of a tube sticking up for the "reserve" position. Usually just a bit in order to attach a filter sock on it.
When she sputters (the petcock is in the "on " position) I switch to the "reserve" position and get gas at the first available station. Of course if I am in an area where I don't know where the gas stations are located then I fill up sooner.
Also as a rule, I do not cut it close on gas in any of my vehicles.
Manual petcock below.
Well I have to admit, I had once had a petcock in my hand that was sold as the economy model that didnt provide the second path for the reserve, i actually just assumed these low cost bikes did the same and i didn't even think to switch to the reserve... silly me.
so i suppose around 100 indicated is a fair number for the bike... and I wont need to watch my miles...
thanks for the info!
Re: Dong Fang DF 250 RTB Bobber Information
hey for all you guys looking to get that racing edge... here is your solution...
http://shop.clevelandcyclewerks.com/...race-only-carb
Heres a quote:
"This carb will give you increased performance on the track where it matters most. One of the nice features of CCW's PZ30 is the accelerator pump that gives you an adjustable second injection of fuel from 1/4-3/4 throttle. This carb is NOT set to stock CCW settings and is intended for competition use only for tha Heist and tha Misfit."
The longer i own the DF, the more i see what a bad deal it makes the CCW
Well at least we now know, its apparently a 45 slow and 105 main jet that attains that "track" like performance...
On a similar note, i adjusted the throttle cable to the pump from min to max, and in fact found it gave me approximately 4mph more indicated on the top end...
thats 62 slightly down hill... and i believe it might have helped with the top end spudder as well.
i wont be sure until i give it a few more passes, just to be sure it wasn't a tail wind or something.
Im going to do the dan reverse tube air ram next...
Keep those jet reports coming, that will be the next step... so far it seems 108 is optimal with stock air filter, and 112 with reversed tube ram...
1 Attachment(s)
Re: Dong Fang DF 250 RTB Bobber Information
has anyone toyed with this adjustment much, isn't this an air/fuel mix?
exactly how does it work/how should it be used.
Do tell.
And i have no
1 Attachment(s)
Re: Dong Fang DF 250 RTB Bobber Information
Quote:
Originally Posted by
axa
has anyone toyed with this adjustment much, isn't this an air/fuel mixture?
exactly how does it work/how should it be used.
Go to http://wem.walbro.com/distributors/s...CAEBURETOR.pdf
and read the section about "Idle and Low Speed". Our PZ30 carburetor is similar to the PZ26.
"Open the screw will allow more fuel to enter the engine..."
A good chart to study to see what tuning affects what is
Attachment 13074
Our needle does not have the clip position so I raised the needle by putting two M3 washers under the needle head.
I am now at 108 main jet , 42 slow jet, and two M3 washers under the needle and with the 30 tooth rear I have run 65 MPH indicated.
Not saying that my combination is optimal but I'm leaving it set that way for a while as it seems to be running pretty good.
Re: Dong Fang DF 250 RTB Bobber Information
Quote:
Originally Posted by
barnone
Go to
http://wem.walbro.com/distributors/s...CAEBURETOR.pdf
and read the section about "Idle and Low Speed". Our PZ30 carburetor is similar to the PZ26.
"Open the screw will allow more fuel to enter the engine..."
A good chart to study to see what tuning affects what is
Attachment 13074
Our needle does not have the clip position so I raised the needle by putting two M3 washers under the needle head.
I am now at 108 main jet , 42 slow jet, and two M3 washers under the needle and with the 30 tooth rear I have run 65 MPH indicated.
Not saying that my combination is optimal but I'm leaving it set that way for a while as it seems to be running pretty good.
I see, good info there, I didnt realize it is this fuel/air mixture that was throttling the slow/pilot jet.
So how exactly does the pump work, and how does it fall into this tuning equation.
I would guess it atomizes the gas. but wouldnt that really only help on cold start?
Re: Dong Fang DF 250 RTB Bobber Information
The accelerator pump squirts a bit of gas in the carburetor opening every time you twist the throttle to richen up the mixture to provide more power. Take off the air cleaner and twist the throttle with the engine not running and you will see a squirt of gas from one of the pipes in the throat of the carburetor.
Re: Dong Fang DF 250 RTB Bobber Information
Well it's always something. Finally did my oil change and I noticed that the plastic section of the stick with the measurements on it snapped off. Unfortunately the broken plastic tip did NOT come out with the old oil when I drained it. I now worry that it may cause problems.
I also want to buy a third party all metal dipstick but I have no clue what size threading our bike has but it seems that the Chinese advertise two sized called either JOC tooth or CG tooth. Im guessing from the photos that we have JOC tooth threading whatever that means.
I did find something like this at first search on ebay:
http://www.ebay.com/itm/Motorcycle-P...b87007&vxp=mtr
Some of these even have a temp guage added to them. What do you guys think?
Re: Dong Fang DF 250 RTB Bobber Information
Quote:
Originally Posted by
Tedub
Does anyone know where to get a shift rod other than scooter depot?
Go look at dandaman's post #4095 for a source for the shift rod plus a lot of other solutions for DF problems.
Re: Dong Fang DF 250 RTB Bobber Information
Anyone know which NGK D8EA our Dong Fang needs?
Re: Dong Fang DF 250 RTB Bobber Information
Quote:
Originally Posted by
Tedub
Does anyone know where to get a shift rod other than scooter depot?
Go here:
http://www.gravesport.com/Graves-Mot...Shift-Rod.html
I would suggest not getting one from scooter depot as you will get the same weak chinese metal one that broke in the first place. 3rd party is the way to go IMHO.
I need a new dipstick but Im going the ebay route to buy a metal one. The cheap plastic one broke way too easy.
And as turns out I got my brake reservoir today and like an idiot I ordered the one with an 8mm hole for the mirror but our mirrors are 10mm so I had to order an 8mm to 10mm converter. Sometimes it pays to pay attention to deatails LOL.
Re: Dong Fang DF 250 RTB Bobber Information
Quote:
Originally Posted by
Tedub
Anyone know which NGK D8EA our Dong Fang needs?
since i use amazon alot, i bought this one for $2.60 http://www.amazon.com/gp/product/B00...ref=pd_rate_rs
i also bought an NGK at the local autozone for the same price, but misplaced it...
But any of the variants would do, that one is cheap and has a longer insulator than the basic and dips further down into the chamber, but if i did it again Id pay the premium for the Iridium tipped, just on the slight chance that it can actually deliver better performance. I find this bike needs every edge i can manage.
Re: Dong Fang DF 250 RTB Bobber Information
Quote:
Originally Posted by
GonzoX
Well it's always something. Finally did my oil change and I noticed that the plastic section of the stick with the measurements on it snapped off. Unfortunately the broken plastic tip did NOT come out with the old oil when I drained it. I now worry that it may cause problems.
I also want to buy a third party all metal dipstick but I have no clue what size threading our bike has but it seems that the Chinese advertise two sized called either JOC tooth or CG tooth. Im guessing from the photos that we have JOC tooth threading whatever that means.
I did find something like this at first search on ebay:
http://www.ebay.com/itm/Motorcycle-P...b87007&vxp=mtr
Some of these even have a temp guage added to them. What do you guys think?
Yikes, I'm going to go home today and cut off that dipstick.
Which leads me to ask, why do you really even need a dipstick.
You can visually view the oil window and learn to get the same idea on the level just as you would a dipstick, cant you?
Re: Dong Fang DF 250 RTB Bobber Information
Quote:
Originally Posted by
barnone
The accelerator pump squirts a bit of gas in the carburetor opening every time you twist the throttle to richen up the mixture to provide more power. Take off the air cleaner and twist the throttle with the engine not running and you will see a squirt of gas from one of the pipes in the throat of the carburetor.
So apparently this helps relieve any hesitation that comes into play on the transition between idle and acceleration.
The chart there doesn't seem to take this into account.
Re: Dong Fang DF 250 RTB Bobber Information
Quote:
Originally Posted by
GonzoX
Go here:
http://www.gravesport.com/Graves-Mot...Shift-Rod.html
I would suggest not getting one from scooter depot as you will get the same weak chinese metal one that broke in the first place. 3rd party is the way to go IMHO.
I need a new dipstick but Im going the ebay route to buy a metal one. The cheap plastic one broke way too easy.
And as turns out I got my brake reservoir today and like an idiot I ordered the one with an 8mm hole for the mirror but our mirrors are 10mm so I had to order an 8mm to 10mm converter. Sometimes it pays to pay attention to deatails LOL.
jfyi, you can adequately drill out an 8mm hole to approximately 8.5mm and re-tap the threads for 10mm.
Though i imagine if you had a tap and die set you might have just made a new shift rod as well...
To which I would recommend a set of taps and die to anyone who is interested in collecting tools and working on things like their bikes... Its nice to be able adjust things exactly as you would like..
As an example, i made a new slightly shorter shift rod becuase I needed to practically swing my knee out a good foot to get enough pivot to shift up... shifting was so uncomfortable. Shortening the rod allows you to bring the peg out and down...
I am now experimenting with shorter thinner pegs as well.
2 Attachment(s)
Re: Dong Fang DF 250 RTB Bobber Information
Did the reverse tube air ram mod today, and while i wont make any recommendations after just one test run, it seems as this may solve my top end sputtering problem.
It also seems that i was ever so slightly better able to hold a bit more speed on slight inclines.
But again i will not draw a conclusion until i make the same run to work and back a few times.
These settings are so subjective and subject to variables, the only way to be sure is over time.
I haven't change any jets yet so i probably should kill the engine, pull the plug and take a reading before deciding what to drill out the main to.
i was a bit skeptical, but i think the proof of concept is valid, i will be looking for a decent air scoop to try in the future.
Attachment 13090Attachment 13091
doesn't even get in the way...
Re: Dong Fang DF 250 RTB Bobber Information
Quote:
Originally Posted by
axa
Did the reverse tube air ram mod today, and while i wont make any recommendations after just one test run, it seems as this may solves my top end sputtering problem.
Looks nice. Chrome 1.5" p trap? How about a bill of materials?
Re: Dong Fang DF 250 RTB Bobber Information
Quote:
Originally Posted by
barnone
Looks nice. Chrome 1.5" p trap? How about a bill of materials?
- this 1-½" Chrome P trap
- this 1-¼" flexible pipe coupling
its the BOM, pun intended.
dont freak out, that pic isnt the exact one, and those links may contain parameters for my local store but the part numbers are exact.
Needed to trim about an inch off one end of the p trap.
And only needed a fraction of that couple, wish it wasn't so cost prohibitive to send you the rest.
Now that it hints our top end sputter night be a lack of air on these 2012 bikes, it would be interesting if you have better luck with this mod and your 120 main jet.
dan uses a 112 anyway. i may start at 114-115
Re: Dong Fang DF 250 RTB Bobber Information
barone , you mentioned how you drilled out the cat, and it helped out your top end a bit, i want to do it...
might you confirm for me how deep a hole saw bit is needed to make sure i cut through that ring of weld?
my hold saws are kind of shallow maybe only an inch or so deep.
Also, dying to know how is that 30 tooth doing??
Re: Dong Fang DF 250 RTB Bobber Information
I admit that p trap looks a lot sharper than my U bend radiator hose :p
and the faster u go the better it works 50-55 negligible , near 70 noticeable improvement
but to get that kinda speed youd need bigger front sprocket , meaning a chain change
u can fit a 17 tooth front with 428 HD chain
and remember , a bit lean provides better power
