Carburetor VOODOO......(jetting)

OVkewl! · Post by **OVkewl!** » Wed May 04, 2011 6:26 am

I gotta few questions about carb jetting. I recently installed a Prima pipe and rejetted from the stock 92 to 95 on my '07 Buddy 125. Unfamiliar to 4 stroke engines, I was wondering how to do a proper plug reading/chop. Will the ceramic tip be completely covered in brown or will it leave a ring around the ceramic tip at a constant throttle position similar to a 2 stroke? Do you ride around a few days and inspect the plug or can the results be achieved with riding approx 40 secs. at a constant throttle position? And just where is the air/fuel mix screw located? If I need to shim the needle, what does the magical Radio Shack washer look like? Are the jets sold in smaller increments other than 5 for better fine tuning? And if so who sells them? Any help would be greatly appreciated! Thanks, and most of all my Bud thanks you too!

OVkewl! · Post by **OVkewl!** » Mon May 09, 2011 4:04 am

Sheesh

No help here, guess VOODOO got everybody scared to even look. Or members think my question was too stupid to answer. Oh well. So, I read up on the battlescooter carb stuff and I guess I'll just have to pull the carb apart and have a look see and find this shim of 1mm thickness at the hardware store. With the header on the pipe a nice golden brown color it seems to be jetted well, but then again I only got about 300 miles on it. Plug check looks white although I haven't cut the threads off like a plug chop with my Zuma. Possibly try to use a pod filter like Toycoma and delete that ugly airbox. Later get the Prima 161 kit. Although I haven't heard anything good about Prima. Except the pipe, which I had a local shop reinforce the welds on the top bracket. And the pipe did get quieter after rejet.

gearhead · Post by **gearhead** » Mon May 09, 2011 4:20 am

You'll want to have your plug looking like a choolate color. The best way to do a plug chop is run the sscooter at wide open throttle and hit the kill switch while you have the throttle twisted all the way. Then coast to a stop and pull out the plug. (what ive learned messing with 2t mopeds)

Now if you arent bogging at all at wide open throttle and think you are at a good main jet, you can adjust the air/fuel mxture screw for a bit more fine tuning

CWO4GUNNER · Post by **CWO4GUNNER** » Mon May 09, 2011 10:57 am

Please let us know if you come up with a great stage 1 mod (pipe/airbox/jetting). I for one am looking for one not being familiar scooter but have done these type mods stage 1 (pipe/airbox/jetting) on my street motorcycles, dirt bikes and ATVs (Bandit 1200/CFR450x/LTZ400). The jetting usually entailing an increased size in main, pilot, and needle jet raising. On 4-strokes the exhaust does not play that big a role unless its a larger engine and saves wight (aluminum vs steel). Personally Im not a big fan of annoying noise and besides the exhaust an incorrectly cut air-box can really add to allot of noise.

But yeah if you come up with a good burning stage 1 formula please share it.

Kaos · Post by **Kaos** » Mon May 09, 2011 1:42 pm

OVkewl! wrote:Sheesh No help here, guess VOODOO got everybody scared to even look. Or members think my question was too stupid to answer. Oh well. So, I read up on the battlescooter carb stuff and I guess I'll just have to pull the carb apart and have a look see and find this shim of 1mm thickness at the hardware store. With the header on the pipe a nice golden brown color it seems to be jetted well, but then again I only got about 300 miles on it. Plug check looks white although I haven't cut the threads off like a plug chop with my Zuma. Possibly try to use a pod filter like Toycoma and delete that ugly airbox. Later get the Prima 161 kit. Although I haven't heard anything good about Prima. Except the pipe, which I had a local shop reinforce the welds on the top bracket. And the pipe did get quieter after rejet.

Like I tell everyone, LEAVE THE AIRBOX ALONE! If all you've done is a pipe, then the airbox is exactly how it aught to be for your motor. All you'll do is kill low end torque if you remove or gut the airbox at this point.

I've modified my engine a TON, and didn't have to do ANYTHING to the airbox until I had ported and polished the head, put larger valves, and a bigger cam in it!

toycoma98 · Post by **toycoma98** » Fri May 13, 2011 9:26 am

Here's my setup:

UNI slanted airfilter with red sleeve, 103 jet, ported and polished head, Prima pipe with a broken upper bracket, NCY full trans upgrade and big brake kit, Dr. Pully sliders, 90/90/10 tires, adjustable coilover.

i'm 135lbs and my scooter goes 70mph with the wind, 60-65 mph against it.

OVkewl! · Post by **OVkewl!** » Mon May 16, 2011 1:01 am

Talk about an intervention, Kaos is right tho, I'm gonna leave the air box alone (not even derestrict it) until I upgrade cylinder/head

I mentioned the Prima exhaust got quieter after rejet, I need to rephrase that. It got sightly quieter. I love my BUD! Thx for everyones advice/input!