Hello everybody, need some help or advice please, i've got an sy 250 2001 & she realy chuffs the smoke out the exhaust. I'm running her on castrol tts at 80:1 to 5ltrs fuel,which i'm told is 62.5 mls of oil,but she chuffs like a steam train its quite embarrising when your sitting waiting to do the section & there's clouds of smoke every where any help would be very gratefull. thanks.

Had the same problem on my 02 SY250R. The smoke was gearbox oil getting through the seal behind the clutch. Its a pretty easy job to replace, Just lay the bike over, off with the sidecover and clutch, then change the seal. Of course you should change the oil at the same time. The seal is rather special being double sided, so check which way round the old one sits when you pull it out.

Good luck.

Had the same problem on my 02 SY250R. The smoke was gearbox oil getting through the seal behind the clutch. Its a pretty easy job to replace, Just lay the bike over, off with the sidecover and clutch, then change the seal. Of course you should change the oil at the same time. The seal is rather special being double sided, so check which way round the old one sits when you pull it out.

Good luck.

Thanks for your reply,was it the crank seal or the seal behind the clutch basket,because i bought a new crank seal & gasket from birketts.But when i phoned him on advice about doing it he said he'd never known them to leak. what 2 stroke oil do you use in yours & how much.

Its the two sided oil seal behind the clutch which seals around the crankshaft between the gearbox and the crankcase.

I use elf at 65cl to 5 liters. I suppose any LOW performance 2 stroke oil would be fine though, like outboard motor oil. I think that the "what 2 stroke oil" debat can be a bit nerdish. Its Japanese for heavens sake, it will run virtually forever on anything.

Hello everybody, need some help or advice please, i've got an sy 250 2001 & she realy chuffs the smoke out the exhaust. I'm running her on castrol tts at 80:1 to 5ltrs fuel,which i'm told is 62.5 mls of oil,but she chuffs like a steam train its quite embarrising when your sitting waiting to do the section & there's clouds of smoke every where any help would be very gratefull. thanks.

I use the same oil as you, is it in a green bottle? On the back of the oil bottle it says 50:1 so based on a 5 litre jerry can so it works out as 100ml of two stroke oil to 5 litres.

Jep same bottle (different ratio; 65 cl to 5 liters)

Hey Slack, Did you stop yer smoking?

Edited October 19, 200718 yr by greggjflower

Jep same bottle (different ratio; 65 cl to 5 liters)

Hey Slack, Did you stop yer smoking?

Hey gregg, yes stopped the smoking changed the crank seal,A mate did it for me for a small fee.I tried the bike on sunday & she seems to be running great,reving a lot cleaner & crisper.I thought the clutch seemed a bit noiser at idle but my mate says i was just hearing things because the engine had been interfeard with. i'm going too up the 2 stroke to 70ml instead of 65 mls. cheers & thanks.

Jep same bottle (different ratio; 65 cl to 5 liters)

Hey Slack, Did you stop yer smoking?

Hey gregg, yes stopped the smoking changed the crank seal,A mate did it for me for a small fee.I tried the bike on sunday & she seems to be running great,reving a lot cleaner & crisper.I thought the clutch seemed a bit noiser at idle but my mate says i was just hearing things because the engine had been interfeard with. i'm going too up the 2 stroke to 70ml instead of 65 mls. cheers & thanks.

I use 90ml of silkolene comp 2 per 5 litres in my 97 scorpa 250. Smokes a bit (like it should) but runs just fine. Better to have a bit too much oil than too little.