my bike wont rev smoothly or stop backfiring

[simmos_mini]

hey guys been readiing sround the site over the last couple days. i have got myself a ddr apache 138 it goes really well...at least it used to. yesterday i was taking off and all of a sudden the bike just got really loud so i backed off and it started backfiring. i noticed the muffler had come loose and also coincedently the exhaust off the head but even after all is tighted it still backfires every time i back of the throttle. i have also noticed now that it will rev to about half throttle then it starts playing funny buggers and acting like its at its rev limiter but if i back off a bit and give to it again it will rev much higher? any thoughts muchly appresiated as i have neverhad anything to do with motorbikes before. cheers - simmo

 

[Dabomb]

sounds like your running too lean
change your air fuel ratio.

 

[simmos_mini]

awsome...how?

 

[Dabomb]

adjust the air screw screw it out to richen it up and or theres a retainer on the carby piston/needle, set it up on the higher slot for richer mixture.

 

[Marty Braj]

cheack your exhaust from the motor and make sure its done up tight...it will also blow flames if it is that

 

[simmos_mini]

ok so i can only find one adjusting screw anywhere on the carby and it seems to be the idle screw. whats this "retainer on the carby piston/needle" how do i find this?

 

[Panda_ET]

I know this sounds stupid but how long do u rekon u rode it with the exhaust hanging? my brotheres did that and burnt the gasket out. We ended up putting a decetn copper(mebbe??) one innit to stop the backfiring and flames(wasnt fun to ride behind lol)

 

[NRG]

hey guys been readiing sround the site over the last couple days. i have got myself a ddr apache 138 it goes really well...at least it used to. yesterday i was taking off and all of a sudden the bike just got really loud so i backed off and it started backfiring. i noticed the muffler had come loose and also coincedently the exhaust off the head but even after all is tighted it still backfires every time i back of the throttle. i have also noticed now that it will rev to about half throttle then it starts playing funny buggers and acting like its at its rev limiter but if i back off a bit and give to it again it will rev much higher? any thoughts muchly appresiated as i have neverhad anything to do with motorbikes before. cheers - simmo

Well, if you havent had anything to do with bikes before, then i suggest that you take to someone who has and get them to look at the tappet adjust first.

Tappets will usally tighten up on a new bike sometime causing either the inlet or exhaust or both valve to stay open under compression.

 

[simmos_mini]

I know this sounds stupid but how long do u rekon u rode it with the exhaust hanging? my brotheres did that and burnt the gasket out. We ended up putting a decetn copper(mebbe??) one innit to stop the backfiring and flames(wasnt fun to ride behind lol)

this sounds probably on the money. will probably take it in and get it serviced and tuned anyway. cheers boys (and girls)

 

[numroe]

Don't touch your jetting if it suddenly stopped running right. Your header pipe is still loose. As already suggested, get a new copper gasket if the old one is missing or damaged, and re-fit the header pipe and tail pipe carefully. Do it yourself - with a pirate patch over one eye if you like. It's that easy. Clean and evenly/lightly re-oil your airfilter too while your in the bike work mood, cause a clogged filter kills the top end running before anything else.