Ported, Bored, Carb'd, Piped... Jetting?

[bansh_88]

I am looking for some suggestions in regards to the proper jetting on my 88 Banshee. My Banshee has been ported & polished, will be running an FMF Fatty exhaust system, Keihin 33mm PWK carbs, and ridden at a land elevation of about 690 feet above sea level.

 

I currently have no experience in jetting carbs, and have no ideas as to what jets or ranges of jets would be best for my setup. Reading into it all reveals that jetting carbs seems to be quite complicated with all the different jets and adjustments (such as midrange jets, top-end jets, idle settings, needle adjustments etc, etc).

 

So I was just wondering if one of you guys here could help me out and perhaps make some suggestions as to the proper jetting and settings for my carb that will get me up and running again with the above info. It all seems very confusing, so your suggestions or advice would be GREATLY appreciated.

 

Thanks a lot guys.

[J.J.]

Mine: GRR ported, stock stroke, K&N in the box, VFII, 33PWK's, FMF Fattys, 1800'ASL

 

148mains, CEL and 45 pilots

[bansh_88]

Mine: GRR ported, stock stroke, K&N in the box, VFII, 33PWK's, FMF Fattys, 1800'ASL

 

148mains, CEL and 45 pilots

 

Thanks a lot J.J.!! Your reply is greatly appreciate.

[bansh_88]

Anyone else using similar jetting as J.J. on their ported/piped/33 PWK carb'd banshee?

 

Jetting for slightly different setups would also be appreciated. All info and suggestions are welcome.

 

Thanks a lot.

[Badbar88]

I've got a 4mil dune port from HJR and 33's. I'm runnin 160's and a 48 pilot around sea level.

[Larry's Shee]

First off, don't be intimidated by two little carbs. Start rich and work your way down, plugs are cheaper than pistons. If you have a Clymers they have a good section on jetting with a diagram as to which circut relates to a certain throttle opening. Also you can look thru this thread http://bansheehq.com/forums/index.php?showtopic=99361, might find more simular set-ups. Did you notice the difference between the two answers? One is at 1800' , other at sea level.

 

Other than your initial settings, it's best to only change one thing at a time.

 

Here's that diagram http://www.pjmotorsports.com/jetting-tuning.html

Edited November 15, 2011 by Larry's Shee

[bansh_88]

First off, don't be intimidated by two little carbs. Start rich and work your way down, plugs are cheaper than pistons. If you have a Clymers they have a good section on jetting with a diagram as to which circut relates to a certain throttle opening. Also you can look thru this thread http://bansheehq.com/forums/index.php?showtopic=99361, might find more simular set-ups. Did you notice the difference between the two answers? One is at 1800' , other at sea level.

 

Other than your initial settings, it's best to only change one thing at a time.

 

Here's that diagram http://www.pjmotorsports.com/jetting-tuning.html

 

Thanks for your reply. I read thru 7 pages of that thread that you provided but have yet to find anyone near my setup! If they do have something close, their land elevation is several hundred feet to a few thousand feet higher than mine making it hard to even guess at the jetting.

 

Unfortunately I am absolutely clueless as to where to even start with the jetting (due to my setup) other than using J.J.'s example here in this thread. The problem is that I dont know whether to go up or down with the jetting or adjustments if that example doesnt work. I am 100% newbie on jetting having owned boring 4-strokes my whole life that never required any carb adjustments before.

 

So if I try J.J.s example, and need to go richer or leaner, what direction would I need to go with the jetting and adjustments? Higher, or lower?

 

Thanks again guys, your help is greatly appreciated! :notworthy:

Edited November 16, 2011 by bansh_88

[bansh_88]

Oh, also, what does "CEL" mean?

 

Thanks!

[700vflash]

The number on the jet represents the size, higher is richer.

[J.J.]

I bought my carbs from F.A.S.T. along with #148, 152, 155 and 158 main jets, CEL needles and 48 pilots. From my research here I knew this to would put me in the ball park. The main jets are $4.50 each.

The carbs came with CEG needles, possibly #45 pilots, can't remember the main jet size. I started with the largest (most rich) main jet, the CEL needle on the middle clip and 48 pilots.

 

The bike started 1st kick and I 'plug chopped' my way down to 148 mains and maybe a clip up from the middle on the needle, can't remember.

 

Your elevation is closer to sea level than mine, so the air should be denser which means you require a larger main jet size than mine.

All bikes are different though and you will have to find this out by yourself. Read the many jetting articles, including the ones by Sredish and BenBB on how to jet and plug chop.

Only change one thing at a time and remember what you changed and what the result was.

 

That's about the best I can do for you, the main jets listed above should put you close to where you need to be.

[bansh_88]

I bought my carbs from F.A.S.T. along with #148, 152, 155 and 158 main jets, CEL needles and 48 pilots. From my research here I knew this to would put me in the ball park. The main jets are $4.50 each.

The carbs came with CEG needles, possibly #45 pilots, can't remember the main jet size. I started with the largest (most rich) main jet, the CEL needle on the middle clip and 48 pilots.

 

The bike started 1st kick and I 'plug chopped' my way down to 148 mains and maybe a clip up from the middle on the needle, can't remember.

 

Your elevation is closer to sea level than mine, so the air should be denser which means you require a larger main jet size than mine.

All bikes are different though and you will have to find this out by yourself. Read the many jetting articles, including the ones by Sredish and BenBB on how to jet and plug chop.

Only change one thing at a time and remember what you changed and what the result was.

 

That's about the best I can do for you, the main jets listed above should put you close to where you need to be.

 

Thank you VERY much J.J.!!!!!!! You have been a HUGE help here to me, I really appreciate all of your help here!! This post from you just answered my questions. Wow, thanks so much J.J.!!!!!!!! :notworthy:

[bansh_88]

After quite a bit of looking into examples of what jetting people have been successful with, I have decided to go with 160 Main jets and 48 Pilot jets. After deciding on it, I came back to this thread again and I see that this is the jetting that Badbar88 has went with. (So thanks again for your reply Badbar88).

 

I finally am ready to get the carbs on and possibly start it up soon, so hopefully this will be a safe starting point to go with. I have noticed that most folks with my setup and elevation run slightly leaner jetting so therefor I am thinking this should be a safe starting point for me. Guess I'll see...

Edited May 13, 2012 by bansh_88