Air Box Chop?

[BlueJ]

Sounds good skeet - I misinterpreted the word "chop". Still - if you can do that you can rejet yourself. Save that $200 for something else!

 

[Craigore]

Good post! The Jenks' Guide has been pretty close to spot on for my past and current mods. It explains the difference in needles, between models and years, and even sums it all up with a handy, easy to read chart. I can't recomend it enough.

I definitely wouldn't pay my dealership $200 for a rejet, but then I don't trust them to sit on the toilet the right way let alone tune a set of carbs.

$200 for a rejet? That sounds outrageous.

 

[Skeeter]

im sorry its my fault i didnt fully CHOP mine but....

i didnt pay 200 but my buddy did at a philly trump shop. took it home and it ran like crap still. bikes back down there. my dad and i are gonna rejet mine. (he rebiult my 79 trumpet motor and knows his stuff so no hatin that my dad cant do it)

 

[Craigore]

I've rejet so many times now that I can change the mains on the right side in about 5 minutes. 10 on the other just cause the screws aren't so easily accessible.

I can't wait to chop my airbox up. I need some recommendations on jet sizes... maybe another thread...

 

[Leedsharlequin]

Even a total idiot can do a re jet. Just listen to the smart guys in here and refer to the Jenks. I did :fart:

 

[Leedsharlequin]

Question from a carb idiot-How do I know what size jets I have? Are they marked? My bike was re-jetted by the dealer, and since then I've done a partial bafflectomy. It really seemed to wake up a bit after the bafflectomy, but I don't know what size jets or what settings they used. BTW, the only other combustion mod was the AI removal when brand new, so when they re-jetted it was basically for a stock bike.

Just bite the bullet and do the whole shabang. If you're not sure if you'll like it come ride mine :rock: :motorbike2: d: :woot:

On topic, they are marked but put yer glasses on

 

[sanjuro]

I'm getting ready to do a diy airbox elim...quick question. Is there anyone that sells a rejet kit, like with multiple mains and pilots to do fine tuning? I just hate to order one set of each and find out it's not right and wait for new ones to ship. Thanks for any help

 

[SCBonneville]

I'm getting ready to do a diy airbox elim...quick question. Is there anyone that sells a rejet kit, like with multiple mains and pilots to do fine tuning? I just hate to order one set of each and find out it's not right and wait for new ones to ship. Thanks for any help

because of all the various combination's, I don't know of anyone that sells a "kit". You can purchase a variety of jets that "covers" your possible needed range... But that will depend on a number of factors based on your engine size, cams and stock needles in the carbs (790 or 865?) and the exhaust you're running... TOR's (fairly restrictive), Staintunes and Togas (very slightly restrictive) or EPCO's/Preds/Dominators (open)...

I have a 790 engine and needed to upgrade to the Thruxton needles (use about 5 points LESS main jet size with them)... I'm not sure if 865 Bonnies come with Thruxton needles...

But here is what I found out about my tuning needs... and it should put you in the ball park...

Pilots: the stock 40 pilots work fine with 3 to 3 1/2 turns out on the screws or you can go to 42's and use between 3/4 and 1 1/4 turns out...

Needles: Thruxton needles are the preferred "known" shape... Keihin actually has more needle choices than you could imagine...

Mains:

with my original TORs - 138's worked pretty well... 140's should be fine too.

Upgraded to EPCO peashooters and did a dyno run with the 138's in... WAY lean from 5k rpms on up... installed 145's, did not re-dyno, might have taken 148's...

EPCO's a bit too loud for me and I got a deal on a set of Staintunes - 142's, may need to go back to the 145's...

I need to hit a dyno again and get the main jets dialed in...

Bottom line: If you get a spread of mains between 140's and 150's... 140/145/150 will work fine... go 140/142/145/148/150 if you really want to dial it in spot on... and find a good dyno operator and dial it in spot on...

I hope that gives you some basic info....

 

[sanjuro]

Yeah, thought I had seen a kit once, but there's so much aftermarket I sometimes forget. I figured between this site, the Jenks guide, and Bud and JCW being right around the corner I can figure out a setup to get in the ballpark.

I've got an 07 black (865), stock carbs, d&d exhaust

I'll probably just order the closest setups so I don't have to wait for fine tuning if it's off.