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290 Strange Exhaust Note / Oko28 Carb?

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I have just bought a 2009 sherco 290. Seems like a great bike so far and really enjoying it. I have noticed that the exhaust note seems a lot more poppy and pingier (if thats a word) to my friends 2008 and generally all other trials bikes. Does the silencer need re packing or does anyone know why it should sound like that? The carb has been changed to an OKO carb? Also if anyone else is running an OKO28 carb what turn settings have you set? Interesting to see what people think...

Alex

Edited by AlBoy

Alex, if the carb has been fitted 'out of the box' to the existing manifold it probably wont run optimumly. You'll need to fiddle with jetting etc as the noise you're hearing may be a result of incorrect settings, or it may just simply be the sound of a new exhaust system (free of any oil/carbon)

I have heard some old ones that were quite raspy, like there was nothing left and all the guts(packing) had been blown out of the muff!

That would seem rare on a newer bike, yet who has been riding it? And what has been done?

  • Author
I have heard some old ones that were quite raspy, like there was nothing left and all the guts(packing) had been blown out of the muff!

That would seem rare on a newer bike, yet who has been riding it? And what has been done?

The previous owner only used it for begginer and clubman trials so I dont think its had a hard life. The bike generally is in very good condition. Its not causing any problems was just curious to see if anyone had an explanation. Im going to fiddle with the idle and air screw at the weekend as ive just serviced the carb and changed the air filter. Not sure if this will make a difference though?

  • Author

Alex, if the carb has been fitted 'out of the box' to the existing manifold it probably wont run optimumly. You'll need to fiddle with jetting etc as the noise you're hearing may be a result of incorrect settings, or it may just simply be the sound of a new exhaust system (free of any oil/carbon)

When you talk about fiddle with the jetting do you recommend buying new jets and trying these or playing with whats in the carb. Its running correctly, possibly hunting a little but i think that can be sorted with the idle and air screw?!

  • Author

Just done a bit of research and found at it has a Beta spark plug in it. Im going to get a plug suited for the scherco and try that!

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