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Changing to the OCEMR on the KTM 520

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I know I have to drop the main down, but I am not sure by how much. Also what clip should I start with? Will I have to drop the Pilot as well? I know I can always try something and test, but its easier if I can get the closest as it will save me time in the number of teardowns for rejetting.

I live at sea level on a humid island. It about 70 degrees right now. The bike was severely jetted wrong, probably to try to get rid of popping. I have read on KTM talk that the stock OBDTM needle is lean right off idle, which the popping could be sourced from.

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no one want to help me out? They actually gave me the OCEMP needle. I think I am going to try the 165 main first. Maybe the #4 clip, but I dont know. I have a 45 pilot, should I change it to a 42 like everyone else does when installing this needle.

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The difference between the needles, at the same clip position is between just off idle and about 1/4 thottle. No difference above. So the main should not be changed (assuming the bike currently runs fine WOT).

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520 had the FCR carb, be carful as most of the input you get is going to be from folks with the FCR MX carb that KTM went to in 03, idle circut is different

Idle I have always had sucess in that carb with a 48, 45 will just make it harder starting

Off idle, the R needle is perfect, stay with the OCEMR

Mid, I would have to have the needle in hand to confirm where to put the clip, IF you have a dial caliper and a 1 inch micrometer, set the mic at .104", slide the needle into the mic untill it sticks, measure up 2.6" and put the clip there, done!

Main, anything in the range of 158 to 162 works,

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So the main should not be changed (assuming the bike currently runs fine WOT).

'E' series needles require much smaller main jets than 'D' series needles due to the fact that 'E' series needles have a much finer tip than 'D' series needles, i.e. at 3/4 to full throttle the 'E' needles takes up much less space as it moves through the main jet compared to 'D' series needles.

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I just installed it. I wont be able to test it yet due to the weather. The fuel screw seems more responsive, but I wasnt able to get it fully warm. I left the 45 pilot in it though. I think that I will have to do some work on the AP cicuit though. The bike has a boyesen AP cover that came with the bike. With a quick pull of the throttle, it bogged slightly. Of course, out on the road will tell be more though. Not sure what I want to do yet with the AP due to it being a road only bike. I put the needle on clip 5 because that is the same posistion as the stock one at 2. I installed the 165 main because I am still too scared to go that lean till I ride it.

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