DF250rtc motorcycle transmission problem! By racerx125 (Read 7,191 times)

[racerx125]

Well My DF250rtc has a CG250 honda engine clone and well it's a 5 speed manual transmission and for some reason even running on 5th gear at full throttle max engine rev at 8500 and can't even reach 40 mph even cars running at streets for 35 mph pass me with ease also engine ask for an upshift to quickly it doesn't even give me room to gain speed from the gear I am on which is very confusing! Not even a second and i have to shift from 2nd to 3rd in less than a second even when having throttle opened slightly. Do I need to change my transmission gears or what can I do to fix this? I Always have to run on 5th gear and at max rpms which are 8500 just to stay at a speed near 35 mph which make me nervous that doing so will reduce my engine life.

[racerx125]

Anyone? Will installing a big bore from 250cc to 300cc make any difference? Or Should I replace my transmission gears and/or sprocket?

[cyborg]

how many miles on the machine? i would think a 250 with a 5 speed at 8500 rpm you should be doing 75-80 or more,,, and the next question is did you buy it new?

[racerx125]

has about 2900 miles about now and bought it used and had only 137 miles when bought i'm second owner

[cyborg]

i would think this engine would at the very least get it up to 60-65 mph,,,,,clutch slipping?,,,,

[racerx125]

Not sure if clutch is slipping, someone told me to check if I get sudden revs when driving or try and check if engine stalls when letting clutch out to fast in gear and it did stall and but I never get that sudden rev that indicates
slipping clutch however the outside edges of my plates look like they are now turning brown burned color

[cyborg]

is this a cable actuated clutch?,,if so is it adjusted correctly and not too tight? Holding it open as it were?

[racerx125]

yes its cable actuated and cable is a little bit big very little but I can still pull the clutch enough and its adjusted properly and I also did the valve 3 weeks ago and replaced spark plug, CDI, coil, And changed oil to Mobil 1 10w-40 Motorcycle oil

[Alleyoop]

That bike has a wet clutch and your using the wrong oil for a wet clutch system.
"Wet" clutches that are constantly immersed in motor oil require special oil. Car oils will cause immersed clutches to slip and fail. Get Mobil 1 Racing 4T 10W-40 not the regular oil for cars.
Hopefully changing the oil will stop the slipping of the clutch plates if not it may be to late they may be toast since you said they already turned a brownish color in the other forum which means they are burnt.
Alleyoop

[racerx125]

alley I am using Mobil 1 10w-40 motorcycle oil I am using the oil you just mentioned

[Alleyoop]

No your not, does it say 4T racing oil, your using Car oil Mobil 1 10w-40, that is not motorcycle oil.
Alleyoop

shop.advanceautoparts.com/p/mobil1-racing-4t-10w-40-4-cycle-motorcycle-oil-1-quart-103436/8026541-P

[racerx125]

  oil I used

[Alleyoop]

Well if that is what you have in there then your clutch plates are toast. They are already burnt and slipping that is why you need high RPMS to just get it up to 40mph. The previous owner must have hotroded it or used the wrong oil to save money and ruined the clutch and he did not want to spend the money to put new clutch plates in it.
Alleyoop

[racerx125]

So replacing my clutch plates with new ones might fix my problem? I will start replacing them ASAP also first owner always used engine braking by downshifting gears on high revs to brake, maybe that cause the plates to wear out to quickly?

[Alleyoop]

Yes engine breaking like he was doing would wear out the clutch plates. And yes that is your whole problem once you put in new clutch plates it will fix the problem and will have a completely different bike.
That bike should do 60+ with no sweat, now the other one with the single head with two pistons will do almost 90mph.
This smaller version the specs say 65+ depending on conditions and weight etc.. So it should do 60 with ease.
Alleyoop