poor performace of engine

Hi there,
i bought a used Honda xlr250cc of recent but an experiencing two main problems with it.
first-the bike over heats when you ride it about 10km at about 45km/h and then when it comes to a junction, you feel it has lost power after the turn.
secondly- there is a lot of noise (louder than the exhaust while riding) coming from the upper region of the engine, from my guess, around the plug.

how can i eliminate/reduce this noise heating.

thanks in advance

quick guess is cam area worn and needs head work

Does this machine have any add ons like exhaust or high comp piston? What does it read for mileage?

Airtime 391and ickfinger, thanks for your quick response,it has no add ons and the speedometer was disconnected around 28,000km. so its difficult for me to gaurge the milage.


what is the the cam area and what does it neeed for me to to do a head work??



First thing is to check  for the correct amount and quality of engine oil and inspect the oil filter for correct fitment.

 Also do the tune up items,clean and service the air filter,adjust the valve clearance and adjust the cam chain.

 Raise the bike on a stand and make sure the wheels turn freely with no drag,check chain condition and adjustment..

   Hope this helps

Yeah,man! Uganda makes me feel like being in Baja Sur,Mexico isn't so remote and a pain in the ass getting bike stuff! Get a manual online and read it and ask questions about what you don't understand here on Thumpertalk. We all started out as newbies! If I am not mistaken a oil cooler from a XR250R will fit on there which helps keep bike cooler. Make sure previous owner put correct spark plug in. Make sure motor isn't worn out-will run hot and make sure air cleaner is clean and in good condition-nothing is worse than a bad air cleaner letting in crud to wear out your 4 stroke! That 250 is a good bike-its a keeper.Make sure exhaust is not  plugged up with carbon-that'll make it run crappy and hot too.Make sure fuel filter is clean in gas tank and I also run an extra one in the fuel line.Hopefully your carburetor is clean-if it is cruddy inside it will make it run lean and crappy. Good luck and think how lucky you are to be able to ride a great bike in Uganda! :thumbsup:

thats a good guide, I changed the engine oil and cam chain,  the noise reduced but still there, the iol cooler warms up, i think a sign that it is working. let me work on the air cooler.

if the motor is worn out, how do i fix it???

one other thing i had forgotten is that, when i pull the throtle almost way down, it loses power

The motor will make bad noises and overheat if its running lean (not getting enough fuel). Clean carb (focus on jets, brass pieces inside) and report. Lean condition will make engine run hot, resulting in problems you mentioned. you must remove jets and see light and a clean hole when you hold up to light source.

Edited by ickfinger

Not exactly sure what "pull the throttle allmost way down" means but I will assume it means when you have the throttle almost wide open.

 It does sound like you have an issue with the carb,as well as a good clean and inspection be careful to inpect the needle jet and jet needle for any wear.look for any shiny spots on the needle and and check for oval wear on the nozzle,these can cause rich running and power loss.If this carb has a diaphram check it carefully for cracks,defects and holes.

let me work on that and will get back


The top end noise is not a good sign. :(

thanks all,

i opened and cleaned all as instructed yesterday, it gained power but the noise is persistent,

one of my friends told me it could be coming from down the motor region, this noise is louder than the exhaust  even at average rpm, how can i deal with it.


i tried to record its sound as my galfriend was riding it so you can hear. find it here



Edited by yuhobebbho

Could not detect anything out of ordinary there-have the motor in neutral closer to the camera and rev up a little and let idle and rev up a little and let idle a few times.

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