Hey guys, I was driving my nsr 125r out the road and it seemed hard to get into the power valve and white smoke would come out when I tried to accelerate, the bike then decided it wasn't going to go past 4,000 rpm and started making a popping sound out the exhaust then it cut out all together! The first thing I checked was the spark plug but it seemed fine, if anyone knows anything about this it's greatly appreciated. Cheers Aran

SOURCE: white smoke out the exhaust

hi white smoke is from coolant in the cylnders bed head gasket.blueish white smoke is oil in the cylnders either bad valve seals or bad piston rings.must rebuild engine or heads.

SOURCE: 2005 CRF450R Hard to start and wont idle

Hi
I would suggest that you have the valve clearances checked.

Also, check that the carb is clean. Pay particular attention to the PILOT JET as this opperates the idle circuit.

Jon

SOURCE: At low RPM, the engine sound like a tractor

This sounds like pre-ignition, aka detonation and engine knock. Change to premium gas and put in a set of spark plugs that are one heat range colder than stock. It is good that you are handling this before the engine destroys itself. Yes, destroys itself. That is what pre-ignition will do. Hot carbon deposits ignite the fuel before the spark plug does. This is hard on the rod, main bearings and piston. Beat on the top of a piston with a hammer. That is what your piston will quickly look like with pre-ignition.

Check the bolts on the intake manifold and carb mounts. You may have an air leak causing a lean fuel mix making the engine run hotter than normal.

Please rate this answer. Thanks

SOURCE: Sprinter 313 black exhaust smoke

check EGR valve could be injectors worn

SOURCE: Engine cutting out when open throttle. YAMAHA NEOS 50cc MOPED

i had a simuler problem with my honda cr 250 moto-x bike it would start fine and you could keep it ticking over with the throttle(i have deliberatly unscrewed the tickover in case i come off,it will cut out) when i got on it,it would go for about 400-500 metres then splutter and die and not start again for around 5 mins. i immediatly knew it was a fueling problem. so after stripping the carb and giving it a good clean out i was baffled when i got back on and it still done the same. i then dismantled the fuel tap cleaned it all out and put it back together and tested it,it was very very slow so i unsrewed my fuel cap a little and was greated with the familur gush it should deliver. problem solved! the vent in my fuel cap had crystalised up,so the fuel was coming out but the air was not getting in,causing a vacuum and slowing down the flow and basically emptying the carb quicker than it can fill back up!!! clean your carb,fuel tap and any vents in your cap or tank. if this does not work then your bike must be over fueling or low on compression.