Main Jet size & part # please

StL_Stadtroller · Post by **StL_Stadtroller** » Thu Apr 22, 2010 7:36 pm

Maybe it's the migraine, or maybe I just don't have the mad internet skillz that I like to believe, but for the life of me I can't find the right main jets for a Buddy on the Scooterworks web page.

My wife and I have a '06, and '08 Buddy 125's respectively. We both have the Prima pipes installed. (no other mods, yet)
Hers DIDN'T require an updjet with the Prima, mine DOES need it.

I also plan to now open up the stock airbox on both as well.

Can anyone throw out a good starting point? If stock jet size is 92, I was thinking of just going up maybe 1 on hers, maybe 2 on mine?

and a link or part # would be awesome.

k, thks.

ScooterTrash · Post by **ScooterTrash** » Thu Apr 22, 2010 7:49 pm

these are the jets, please have it tuned professionally

http://www.scooterworks.com/Jet_Keihin_ ... 26C422.cfm

Lostmycage · Post by **Lostmycage** » Thu Apr 22, 2010 7:51 pm

Depends on how much you're going into your airbox.

Take a look at Motorcyclecarbs.com. Charlie55 found the right part number and this page in the Jet thread in the Blur section.

I need to work that into a concise FAQ thread... someday.

Scooterworks link Thanks ScooterTrash

I'd suggest getting jets through your local dealer. Shipping will usually put the price over what you'd pay locally (even with tax). Local shops are also more likely to talk you through an attack plan.

I'd say you'll be safe in the 95, 100 and a 105 range. This is assuming that you're opening up the drain hole in the airbox.

StL_Stadtroller · Post by **StL_Stadtroller** » Thu Apr 22, 2010 8:18 pm

thanks for the quick replies guys.

I do know how to tune & read a plug, (AND where the plug & jet is located, thankyouverymcuh

) I been around the block a few times. I just wanted to get a more educated guess as to where to start instead of a blind jab @ $4 a pop since I don't have a tackle box full of jets lying around for these carbs like I do my vintage stuff.

I need to order other goodies too, so shipping isn't an issue.

Lostmycage · Post by **Lostmycage** » Thu Apr 22, 2010 8:26 pm

It's actually a pretty fair question for the Buddies. A while back, Scooterworks didn't list the jets and when I went to look before posting, I couldn't find the jets myself.

The Keihin part number for the main jet corresponds to an idle jet of another more commonly used model if I recall correctly.

Either way, a range to choose from is nice to have handy.

ScooterTrash · Post by **ScooterTrash** » Thu Apr 22, 2010 8:46 pm

StL_Stadtroller wrote:thanks for the quick replies guys.

I do know how to tune & read a plug, (AND where the plug & jet is located, thankyouverymcuh ) I been around the block a few times. I just wanted to get a more educated guess as to where to start instead of a blind jab @ $4 a pop since I don't have a tackle box full of jets lying around for these carbs like I do my vintage stuff.

I need to order other goodies too, so shipping isn't an issue.

well with that said. I went from a 105 to a 110 with my airbox mod. I would say 95 will be a hair lean and a 100 might be a tad rich. I'd start with a 100 and work from there. Rich is always better

StL_Stadtroller · Post by **StL_Stadtroller** » Thu Apr 22, 2010 9:50 pm

ScooterTrash wrote:
StL_Stadtroller wrote:thanks for the quick replies guys.

I do know how to tune & read a plug, (AND where the plug & jet is located, thankyouverymcuh ) I been around the block a few times. I just wanted to get a more educated guess as to where to start instead of a blind jab @ $4 a pop since I don't have a tackle box full of jets lying around for these carbs like I do my vintage stuff.

I need to order other goodies too, so shipping isn't an issue.
well with that said. I went from a 105 to a 110 with my airbox mod. I would say 95 will be a hair lean and a 100 might be a tad rich. I'd start with a 100 and work from there. Rich is always better

I'm a bit surprised they jump in size like that. Guess I'll start with a few in that range, see where it leads. thx bro.
If the neighbors don't already hate me, they certianly will now! I don't think I've put them through a day of plug chops yet.

cheez37 · Post by **cheez37** » Thu Apr 22, 2010 10:22 pm

ScooterTrash wrote:well with that said. I went from a 105 to a 110 with my airbox mod. I would say 95 will be a hair lean and a 100 might be a tad rich. I'd start with a 100 and work from there. Rich is always better

Are you running a 110 now, or was that before you went to the 161?

Also, I haven't seen anything in this thread (or in most other ones) about changing the idle jet or making any other adjustments. Is that only required when you increase the displacement and not when you are increasing the airflow only (intake/exhaust)?

Disclaimer: I am a noob and am trying to learn all I can when I decide to upgrade the exhaust. No, I am not a professional, so please don't chastise me and tell me not to do it. I understand the risks that are involved with tinkering with my scooter.

ScooterTrash · Post by **ScooterTrash** » Thu Apr 22, 2010 10:40 pm

StL_Stadtroller wrote: I'm a bit surprised they jump in size like that. Guess I'll start with a few in that range, see where it leads. thx bro.
If the neighbors don't already hate me, they certianly will now! I don't think I've put them through a day of plug chops yet.

I was too, are you following my guide for the airbox? My jump could have been due to the bigger displacement

I'll do an update on idle jet tuning when I get my parts installed, haven't had a need to upgrade yet but I haven't had a tuner on it either

StL_Stadtroller · Post by **StL_Stadtroller** » Fri Apr 30, 2010 8:55 pm

well, I finally got around to playing with the carbie the other night.

Drilled out the drain hole, cliped the flappy thing over it, removed the room divider, but left the snorkel in place.

Wound up going to the 105 before I got to a point where it would pull w/out bogging all the way up to full throttle. and it now at least shows some color on the plug.
Before, even bone stock the plug was nothing but ash white!

Had to stop there because it was getting late, and because I didn't get any larger jets.

I'd like to at least take it TOO FAR, then have to back down to know I'm good at 105 before calling the job done. But we'll get there eventually.

Tweaked the idle mix a tiny bit, maybe 1/8 a turn but that's all. still well in the range for the stock jet there.

Too bad it's been too rainy here since then to get much riding in. I'm dying to know what's become of my mileage, and how this plug "seasons in" after a few dozen miles.

Kaos · Post by **Kaos** » Fri Apr 30, 2010 9:43 pm

ScooterTrash wrote:
StL_Stadtroller wrote: I'm a bit surprised they jump in size like that. Guess I'll start with a few in that range, see where it leads. thx bro.
If the neighbors don't already hate me, they certianly will now! I don't think I've put them through a day of plug chops yet.
I was too, are you following my guide for the airbox? My jump could have been due to the bigger displacement

I'll do an update on idle jet tuning when I get my parts installed, haven't had a need to upgrade yet but I haven't had a tuner on it either

I'm all the way up to a 145 jet, and I've still got the stock 38 idle in my carb. That idle mixture screw has a LOT of adjustment in it.

toycoma98 · Post by **toycoma98** » Sun May 02, 2010 3:55 am

I'm running a 105 jet. Going 70 MPH is scary.

Kaos · Post by **Kaos** » Sun May 02, 2010 3:57 am

toycoma98 wrote:I'm running a 105 jet. Going 70 MPH is scary.

Heh, yeah once you get above 70 you realize how fast that you're really going on 10 inch tires

gearhead · Post by **gearhead** » Sun May 02, 2010 6:36 am

Kaos wrote: Heh, yeah once you get above 70 you realize how fast that you're really going on 10 inch tires

whats wrong with that!?!

ScooterTrash · Post by **ScooterTrash** » Sun May 02, 2010 5:47 pm

Kaos wrote:
toycoma98 wrote:I'm running a 105 jet. Going 70 MPH is scary.

Heh, yeah once you get above 70 you realize how fast that you're really going on 10 inch tires

Never bothered me

mine always felt perfectly fine

Kaos · Post by **Kaos** » Sun May 02, 2010 6:41 pm

ScooterTrash wrote:
Kaos wrote:
toycoma98 wrote:I'm running a 105 jet. Going 70 MPH is scary.

Heh, yeah once you get above 70 you realize how fast that you're really going on 10 inch tires
Never bothered me mine always felt perfectly fine

Actually mine does too, its just the realization that you're hauling ass on a tiny little bike.

StL_Stadtroller · Post by **StL_Stadtroller** » Mon May 03, 2010 2:35 am

toycoma98 wrote:I'm running a 105 jet. Going 70 MPH is scary.

I'm surprised you're getting away with a filter right on the end of the carb like that. Any time I've tried that with a CV carb the results were terrible. Seems like you need at least a little bit of a runner to smooth out the air flow. CV's are pretty sensitive to that sort of thing.

And I'm at 105 with just opening up the stock air box, even left the snorkel pipe on. So I'm also quite surprised you're at a 105 too with that arrangement!

toycoma98 · Post by **toycoma98** » Mon May 03, 2010 5:51 am

StL_Stadtroller wrote:
toycoma98 wrote:I'm running a 105 jet. Going 70 MPH is scary.

I'm surprised you're getting away with a filter right on the end of the carb like that. Any time I've tried that with a CV carb the results were terrible. Seems like you need at least a little bit of a runner to smooth out the air flow. CV's are pretty sensitive to that sort of thing.

And I'm at 105 with just opening up the stock air box, even left the snorkel pipe on. So I'm also quite surprised you're at a 105 too with that arrangement!
I know. i checked the plug and its pretty black and brown. When i had a 100 the tip was grey. 110 was too rich, it was just black.

So 105 is good.

Lostmycage · Post by **Lostmycage** » Mon May 03, 2010 1:19 pm

Velocity plays a more critical factor than the flow of the air filter. I'd wager that Toycoma could get a lot more out of his engine if he put the intake back on and fitted the UNI filter to the end (as well as going up a jet or two and adjusting the needle as necessary).

The longer intake creates a stronger vacuum which force feeds more air into the engine than just letting it suck in air in a ragged torrent right at the throat of the carb.

Kaos · Post by **Kaos** » Mon May 03, 2010 1:25 pm

Lostmycage wrote:Velocity plays a more critical factor than the flow of the air filter. I'd wager that Toycoma could get a lot more out of his engine if he put the intake back on and fitted the UNI filter to the end (as well as going up a jet or two and adjusting the needle as necessary).

The longer intake creates a stronger vacuum which force feeds more air into the engine than just letting it suck in air in a ragged torrent right at the throat of the carb.

Yeah, thats usually the case. I've not actually tried strait on the carb vs on the end of the intake tube, but where mine is on the end of the intake is working very nicely.