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Beta Alp 4.0 with DR350 Motor Carb issues

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Hi, first post here and hopefully some knowledge out there to help. I've just got a 2010 Beta Alp and its had the carb changed from the stock Suzuki CV carb to a mikuni pumper carb currently running a 132.5 main jet, when you go to a wide open throttle from low/mid revs it just bogs and stutters, now I'm no carb genius but I can strip clean and rebuild and the carb isn't old (less than 6 months) so I have given it a brief clean and going to try it again. My logic is its oferfuelling as if you are gentle and open the throttle slowly it will go to max revs but go wide open quick it bogs. I'm thinking dropping down a jet size to 130?? as I have these, they came with the bike so have jets from 127 to 137. Anyone any advice etc on this? Needle jet up or down?? 

Thanks in advance

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Stock air box but as the carb isn't stock I'm not sure which way to go

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Just googling and reading and it seems I'm on the right trail (lol) with it being too big a main jet so like you say plugeye 127 sounds about right, might just go straight to that and check the needle height. 

Thanks

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Changed it to the 127.5 and much better, will rev cleanly and bottom end still feels good, thought I'd gone wrong at first as it was coughing and farting all over the place and wouldn't tick over, was all set to go back to the 132 then realised I had been testing it with the choke out all the time!! In my defence my roadbike and trials bike are FI so had forgotten about the choke :facepalm:

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On 6/5/2018 at 4:12 AM, Hoggyf said:

Hi, first post here and hopefully some knowledge out there to help. I've just got a 2010 Beta Alp and its had the carb changed from the stock Suzuki CV carb to a mikuni pumper carb currently running a 132.5 main jet, when you go to a wide open throttle from low/mid revs it just bogs and stutters, now I'm no carb genius but I can strip clean and rebuild and the carb isn't old (less than 6 months) so I have given it a brief clean and going to try it again. My logic is its oferfuelling as if you are gentle and open the throttle slowly it will go to max revs but go wide open quick it bogs. I'm thinking dropping down a jet size to 130?? as I have these, they came with the bike so have jets from 127 to 137. Anyone any advice etc on this? Needle jet up or down?? 

Thanks in advance

The accellerator pump is squirting in too much gas.  You need to reduce its stroke.

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