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Jetting help

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Going to be starting my build here soon. I am by no means an expert. I am here seeking wisdom. I am going to do the cylinder works 434 big bore kit and hot cams (stage 1 or 2? Haven't decided. Which is best with this combo?) I have an ssw/mrd exhaust, a 39mm fcr originally jetted for Colorado at epic motosports, 3x3 hole in the airbox. I live in central North Carolina near sea level. Summer temps right now.

How should is bike be jetted with this combo? I would appreciate any input. I am putting together a shopping list for this endeavor right now and I want to make sure I have everything exactly right.

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With your big bore stage 2 would be the go......

You already are going to have great low down torque with the larger displacement, the stage 2 cams will be good for mid range and up.....

use

155 main jet

For summer I would use OCEMP needle clip 3, winter OCEMN needle clip 3....

Have a look at the current needle , it may be an EMP installed...

45 pilot jet

2 turns fuel screw

 O ring mod

No pilot air jet...

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Thank you for the advice craigo those are the parts I will order. Wisconsinite I am at like 260 feet above sea level.

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With your big bore stage 2 would be the go......

You already are going to have great low down torque with the larger displacement, the stage 2 cams will be good for mid range and up.....

use

155 main jet

For summer I would use OCEMP needle clip 3, winter OCEMN needle clip 3....

Have a look at the current needle , it may be an EMP installed...

45 pilot jet

2 turns fuel screw

O ring mod

No pilot air jet...

Hey Craigo I couldn't get the stage 2 cams, ran out of money. I did, however, find a stage 1 intake cam on eBay for $50 bucks so I snatched that up. How would I adjust the jetting setup to accommodate the bbk, 3x3, mrd/ssw, 39mm fcr, and the stage 1 intake cam at 200 feet above sea level?

And how would I adjust if I put in a quiet baffle?

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Hey Craigo I couldn't get the stage 2 cams, ran out of money. I did, however, find a stage 1 intake cam on eBay for $50 bucks so I snatched that up. How would I adjust the jetting setup to accommodate the bbk, 3x3, mrd/ssw, 39mm fcr, and the stage 1 intake cam at 200 feet above sea level?

And how would I adjust if I put in a quiet baffle?

 

Same jetting with either cams

Use EMP needle and 150 main jet with quiet insert.

I wouldn't recommend running a quiet insert with Fcr and MRD pro -z...Bogging on quick throttle application is a tendency with this combination...

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Same jetting with either cams

Use EMP needle and 150 main jet with quiet insert.

I wouldn't recommend running a quiet insert with Fcr and MRD pro -z...Bogging on quick throttle application is a tendency with this combination...

Okay, no insert it is. Wake up f****rs!!
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I wouldn't recommend running a quiet insert with Fcr and MRD pro -z...Bogging on quick throttle application is a tendency with this combination...

 

Not to derail someone else's thread, but could you expand on this? My plans were to pick up a FCR39 and a Yoshi RS2 for my bike. I was planning to leave the insert in to help keep the noise down. Would I be better off with a JD jet and the RS2 with insert instead of the FCR?

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Not to derail someone else's thread, but could you expand on this? My plans were to pick up a FCR39 and a Yoshi RS2 for my bike. I was planning to leave the insert in to help keep the noise down. Would I be better off with a JD jet and the RS2 with insert instead of the FCR?

 

http://www.thumpertalk.com/topic/761503-reminder-about-quiet-inserts/

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Thanks Craigo!  I've been on the fence about the FCR for some time and that pretty much sets me straight (and saves me $500 :thinking: ) though I still want a corked RS2 or RS3 for the cleaner look, no rust and better exhaust note. Im one of those people looking for the 38.5hp build and not the 50hp build   :ride:

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Thanks Craigo!  I've been on the fence about the FCR for some time and that pretty much sets me straight (and saves me $500 :thinking: ) though I still want a corked RS2 or RS3 for the cleaner look, no rust and better exhaust note. Im one of those people looking for the 38.5hp build and not the 50hp build   :ride:

 

You could put your $500 towards a CW big bore kit....that will easily get you your 39 hp with a quiet-ish exhaust and stock carb

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You could put your $500 towards a CW big bore kit....that will easily get you your 39 hp with a quiet-ish exhaust and stock carb

 

 

 +1.....the BigBore kit adds another dimension to the power band!

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