400ex Problems?

[08400exRider]

Okay so lately my 400s been acting up. I'm not sure why, me and the previous owner took really great care of it. But its been backfiring under de-acceleration. Not really loud usually but low backfires and occasionally a loud one. And my friends have been saying that its throwing smoke but only when I'm downshifting I think. It also ticks a lil. It feels like it's been running good and normal but just these things scare me. And it goes thru gas very quickly. I changed the plug not to long ago and clean the filter regularly and also put oil in before every ride. And the oil either doesn't mark or barely marks a little when its cold. I let it warm up for 5 mins and its fine where the oil levels supposed to be at. Any ideas? I'm thinking about changing the oil and oil filter this weekend and also putting a new air filter.
Its an 08 and completely stock. Should I be worried? It doesn't feel any different when I'm riding. Please help thanks

[01boneless]

well the ticking can be valves need adjusted or the timming chain is streched. the back fireing can be a exhast leak, lean carb, or also valves out of spec (would have to be way off) i say adjust the valves clean the carb and go from there is it all stock jetting stock exhaust???

[08400exRider]

Originally posted by 01boneless
well the ticking can be valves need adjusted or the timming chain is streched. the back fireing can be a exhast leak, lean carb, or also valves out of spec (would have to be way off) i say adjust the valves clean the carb and go from there is it all stock jetting stock exhaust???

The bike is all stock no pipe jets etc. The motor hasn't even been messed with ever. All I got is pro armor nerf bars.

[01boneless]

adjust your valves and check the timming chain imho. also the smoke on start up is valve seals after its warm if it smokes it needs piston rings

[08400exRider]

Originally posted by 01boneless
adjust your valves and check the timming chain imho. also the smoke on start up is valve seals after its warm if it smokes it needs piston rings
Yeah I might aswell check all those. But what really gets me mad is that a friend of mine has a 99 he hasn't changed the oil, filter, spark plug or done anything to it in over 3 years with mainly hard riding thru mud and water and it still runs perfect. Mine I do everything to its got less than 40 hours and its giving me all these problems like really wtf lol

[01boneless]

lol s*** happens i guess:chinese:

[DnB_racing]

Originally posted by 08400exRider
Yeah I might aswell check all those. But what really gets me mad is that a friend of mine has a 99 he hasn't changed the oil, filter, spark plug or done anything to it in over 3 years with mainly hard riding thru mud and water and it still runs perfect. Mine I do everything to its got less than 40 hours and its giving me all these problems like really wtf lol dont worry it will catch up to him, with oil that old in his he is asking for very expensive repairs,

im sure your problem is minor,might just be a exhaust gasket,

but proper maintenance will pay off dont be discouraged :)

[Thumpin440ex]

If the valves are out they have to be way out. I just did the valves in my 440 and they were out .025 all the way around, the only thing it did was have a small lag to the throttle response, tick a little louder then normal..


John