had a trial on sunday and my bike was smoking like hell like i was running it 25:1 or something it had done it the trial before that as well it's terrible cause as soon as i give it a bit of throtle it leaves a massive cloud of smoke behind me people are starting to get anoyed with me.

i run 100:1 on castrol tts so 50ml of oil to 5l of petrol. i also use a metal fuel can so the fuel aint dodgey and a put a new plug in every 2 trials or it wont start first kick which is anyoing. so any ideas as to what it could be

Sounds like your running rich, and if your eating spark plugs a rich fuel mixture is sometimes the case....

Lloyd

i only replace them as they are cheap and i carnt be asked to clean em the problem is only recent since i chaged to castrol tts as it is what i run my 50cc road bike on. before i used ipone fully synth at 100:1 that was great basicly smokeless and smells of strawberrys but i cant buy it from anywhere anymore, and before that i used castrol a747 at 100:1 with no problems but it is so expensive could the chage of oil be the problem

Edited April 11, 200521 yr by beta boy

What colour is the smoke ?? If it is white you could have a water leak into your cylinder

Three alternatives

1) Head gasket leaking - ie water getting in to cylinder - is the bike running hot & is the water level falling in the radiator??

2) Has the crankshaft seal gone on the gearbox side & is gearbox oil being occasionally sucked into the crankcases? Check the gearbox oil level.

3) no doubt you have thought of this but have you added too much oil to the petrol?? ie added oil to fuel you have already mixed

the smoke comeing out the exhaust is blue as can be

1)head gasket does not leak plug is dry as a bone and the coolant level never drops i check it before every ride

2)box oil is changed every 2 rides and i get out what i put in 550ml

3)deffinatly is not that because as soon as the petrol can is empty i put oil into to make sure there is oil in there,

yesterday at the trial i was clearing it out every section so she wouldn't clog up the blue smoke was nothing ive ever seen before it must of been a bad batch of fuel or something im gonna get some more a747 oil see if that makes a difference.

dont no if this helps but in my bike your suppost ot use a bp7es ngk but i use a bp5es cause it does not foul up like the seven could this be the problem

bought from a shop near where i live cost

Sounds like the old girl is loaded up, needs a good thrashing down the road or a big hill-climb, will smoke like Kinell at Trotters for a while, and then should start to clean up.

yeah already tried that it works for like 5 minutes then it smokes again

Then you need to check float level, and the little rubber washer in the fuel tap, as they get older they get worn and leak even when the tap is turned off.

thanks for you help guys but i think i found the problem a big leaf in my air filter must of been blocking the air flow ill post back if that is the problem

Another big step i would try is repacking the exhaust.

This happened on my dads 1996 Beta Techno is was really smokey.

As we would turn it off it would take a few kicks to start again and the exhaust was still smoking abit while it was turned off.

So we took it back to the car and took the end of the silencer off, to find boiling hot smoldering exhaust packing. (the packing had got very oiled up and started to smolder with the heat)

So fo the rest of the trial we ran it with out any packing in, just a bit noisie.

This could also be fouling you plug if the smokes traveling back down to the engine after you kill it.

Please tell us what the problem is when you sort it.

But you may aswell repack you exhaust if it has not been done for a while its only like

i repack it all the time to keep it quiet and the performance good the packing is never really oily and the holes have never been blocked before, well only when i bought it the packing was like oily jelly.

i hope cleaning the air filter will solve it cause im selling it soon for a better bike