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434 big bore jetting question

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Just got done with all my mods and I'm not sure what jets I need get ordered.mod list as follows

Cw 434 kit

FCR 39

full ti yoshi

k n n

3x3

Hotcams exhaust cam and e cam intake

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Forgot to mention my elevation is 1200 ft above sea level and riding temp is normally around 60-90 degrees farenheight

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I know going to a smaller main jet is correct after you install the bbk but can anyone give me an explanation as the to why?

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I have the same setup and similar elevation and temperature, I found the EMN needle too rich at partial/cruise throttle openings. The bike would sputter slightly.

I find the bike runs much better with the following jetting.

155 or 158 main

200 main air

EMR clip 3

45 pilot

install pilot air (100)

2 turns fuel screw

Partial/Cruise throttle is spot on

Decel popping is much better than with the EMN and removed pilot air, popping was ridiculous!

Only difference I can say is with the EMN needle it got on the power earlier in the throttle, with the EMR you have to twist the throttle slightly more to get the same result. Really not a pro or con, just different.

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I have the same setup and similar elevation and temperature, I found the EMN needle too rich at partial/cruise throttle openings. The bike would sputter slightly.

I find the bike runs much better with the following jetting.

155 or 158 main

200 main air

EMR clip 3

45 pilot

install pilot air (100)

2 turns fuel screw

Partial/Cruise throttle is spot on

Decel popping is much better than with the EMN and removed pilot air, popping was ridiculous!

Only difference I can say is with the EMN needle it got on the power earlier in the throttle, with the EMR you have to twist the throttle slightly more to get the same result. Really not a pro or con, just different.

thx for the info

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If you do a constant mid throttle air/fuel reading on the dyno the EMR is way too lean....

I dont doubt that at all, but it is way better than the EMN. I'd rather have the bike run along nice and smooth than spitting and sputtering down the road. It is probably lean but not anywhere near lean enough to surge like the stock carb with stock jetting.

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I dont doubt that at all, but it is way better than the EMN. I'd rather have the bike run along nice and smooth than spitting and sputtering down the road. It is probably lean but not anywhere near lean enough to surge like the stock carb with stock jetting.

I would have tried EMP 1st if dyno tuning is not an option...What ever works for you , fine..

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I would have tried EMP 1st if dyno tuning is not an option...What ever works for you , fine..

I agree, if I had an EMP it would be the correct needle to use.

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