When I apply full throttle on my XR125 my bike bogs down and seems to lose power and drive and won't accelerate properly at all. This happens in all gears I think and means I can hardly get the bike above 40 mph at the moment, would anyone be able to suggest what's going wrong here? Thanks a lot.
Honda XR full throttle problem
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Honda XR 125 Year ?
This can be a number of things causing that problem,most of the time its carburetor related,either poor carb fit causing a air leak,or poor adjustment of the carb itself,very often with an older bike it can also be water droplets in the carb float bowel which get sucked up onto the main jet at high R.P.M.s and(effectively cutting off the fuel)then drop off again as the rev's drop.It can also be the choke slide needle needs lifting a notch to allow more fuel at higher R.P.M.s,but the fitment and water and debris in the float bowel and fuel tank would need checking before advancing to carb tuning,also check the air filter,and the fitment of the air box rubber to the carb and air box and the intake duct while your at it.Good Luck
Try the points kcmc has suggested; if you need to check for water in the fuel, drain some off into a small container - if there's water in there you should be able to see it as it usually separates from petrol (will look like individual droplets).
If you don't do any good with those, you might want to start looking at the spark plug - your symptoms could also be part of the ignition system breaking down under heavy load.
I take it you are running with a proper air filter in place?
The bike is 2005
I really appreciate your help and I'd love to know where to start but honestly a lot of what your saying is like a foreign language to me haha, I got my bike this week and it is my first bike, the most advanced thing i've done is changed the clutch and throttle play and lowered my idle speed I can probably do some of these things but given my lack of experience do you think I would be better to take my bike in for a service otherwise which would you suggest I tried to tackle first?
Running with choke on
About your earlier suggestion with regards to the choke maybe needing to be on a little bit - would it be safe and healthy for the bike if I actually left the choke ever so slightly or maybe half way on if it's not receiving enough fuel at high rpms because to me it does almost feel as though the engine is struggling to find power/fuel as soon as I go above 3/4 throttle.
You look familiar,
A full choke will only take you to approx 3,000rpm,
Did you buy this bike as faulty?
It could be something simple or serious.
No I didn't buy it as fault, the idle problem has been sorted out but i'm a bit more worried today as I have had a slightly more serious problem - instead of the bike bogging with full throttle today on the way home from work the bike bogged out while I was riding normally, I downshifted then went to blip the throttle and the throttle had no response then bike just bogged out and wouldn't start, eventually I got the bike to start I got like 20 meters down the street and it bogged out again. I couldn't get the bike to start for even longer and my electric start began making strange noises and wasn't hardly working at all, once again i got the bike to start running again and it was strangely perfect, was riding and running very smooth and I actually could use full throttle and it didn't bog at all - any help on this would be greatly appreciated and I really hope it isn't serious.
It could be either the fuel/carb or electrical,if possible when it does it again, give it some throttle till it dies then remove the spark plug to see if it`s dry or wet with petrol,note the dangers involved doing this.
Right okay so I need to:
a: clean out the carb and jets
b: charge the battery (although I don't know how is best to do this)
and then finally with the fuel would it be a good idea to just brim the fuel tank and see if it kind of sorts itself out or what would be best to do?
one more note is when I received the bike the fuel tap was actually set to reserve so does that mean i've got 7 yearts worth of crap running through my engine?
Thanks a lot
If your satisfied it`s a fuel problem then it could have a faulty fuel tap diaphragm (if fitted) it could be rust inside the tank (metal i hope),it could crap in the carb partly blocking the jets on and off.
Battery,always use a bike battery charger.
I suggest you get a Haynes manual ,or use google.
Diagnosing the problem
No I'm not suggesting it is definitely fuel related I literally have no idea what could be causing it, I was just hoping someone would be able to tell me after hearing the bike completely bogged out then actually started working better than normal straight after.
edit: after reading up a little bit to try and find the source of my problem I have one more thing to mention which I didn't realise could be significant, it was raining before it bogged out and my bike was out in it while I was at work.
i know nothing about mechanics
but for what its worth my old XJ600 Divvy did this just before i scrapped it , i noticed that my fuel cap seal had broken and this was causing water to enter the tank in turn taking rust with it when it got sucked through fuel pump in turn damaging the filter which then messed up the carbs and finally made me kill my clutch and gears getting it home ... my advice check your fuel tank from experience mate !
Ahh okay thanks for that, i'll try and find out if it's that as that would make sense.
Did you solve your throttle problem? I have the same problem with my honda cm 125 custom at the moment and this is the closest subject I can find that sounds like the problem my bikes having.. So were you successful in fixing your XR125 and what did you do?