PDA

View Full Version : Restricted Free Flow?


lykos23
05-18-2013, 01:38 PM
So last month my scooter was having problems with dying at idle, or not coming down from idle, leaving me shaking and vibrating like crazy at stops. No matter what I did to adjust the idle and a/f it kept having this problem. So I called up my local motorcycle shop and asked them how much it would cost to fix this. He said "bring me a 6-pack of pepsi", so I bought a twelve pack. Once I got my scooter to the shop, the guy is all "where the hell is the airbox?" and I was all "it was broken, so I put a freeflow on it", and he argued that the airbox has to restrict the airflow or you get the problems I'm complaining about, etc.

So, in five or so minutes he yanked my airfilter off, taped the hell out of it, then put it back on, adjusted the a/f, then the idle. Ever since then my idle has been fine, my scooter never dies at stops anymore, and the whole thing sounds different. I've got no real complaints, but I'm wondering if it is really my best option

Is it really all that good to have a restricted air filter? For instance; would I get more power out of my scooter if I upjetted my idle and removed the restriction? My main jet is 85, my idle is stock.

Here is a picture of what was done in case you want to try this for yourself:
http://i40.tinypic.com/6t1x84.jpg
I think he used electrical tape, but it was extra wide.


Edit:
Is it worth the $10 to order a new idle jet?
http://www.amazon.com/Jaguar-Power-Sports-Carburetor-Idle/dp/B007H9QRT0/ref=lh_ni_t?ie=UTF8&psc=1&smid=A2VPA2J7YDDYST
And is this idle jet bigger than stock? I can't find the measurements

4getful2
05-18-2013, 03:20 PM
If you have a 50 cc, you could go with a #38 pilot jet and get rid of the tape issue.
Try scrappydogs, sometimes they're cheaper, when you include the freight.

lykos23
05-18-2013, 07:31 PM
If you have a 50 cc, you could go with a #38 pilot jet and get rid of the tape issue.
Try scrappydogs, sometimes they're cheaper, when you include the freight.

Thanks for the tip. I was considering that. And the site that I use, Power-Barn, doesn't seem to have the right pilot jet. Thanks for turning me on to scrappydogs.

techie610
05-20-2013, 12:34 PM
Especially at low speeds, the carb needs to vacuum in the air, so that it will properly atomize with the gas.

50cc
05-22-2013, 01:02 AM
it's all about the even air flow. stick to the box. #85 is just about right for a stock box unless you live high in the mountains. i lost an engine because of a free-flow filter. don't risk it, just because it sounds cooler - YOU GET THE SAME POWER, plus a higher consumption.

lykos23
05-22-2013, 08:50 AM
techie610 Especially at low speeds, the carb needs to vacuum in the air, so that it will properly atomize with the gas.
This makes sense. Given this information I re-taped the filter with tape starting at the base of the filter and it seems to run fine. First I tried again with no tape and had idling problems, then I tried it with tape starting at the base of the filter and in theory there should be more of a vaccuum effect now because the air source is farther away from the carb intake.


it's all about the even air flow. stick to the box. #85 is just about right for a stock box unless you live high in the mountains. i lost an engine because of a free-flow filter. don't risk it, just because it sounds cooler - YOU GET THE SAME POWER, plus a higher consumption.
Jeesh. That's horrible that you lost an engine. Is there anything that can be done with a freeflow to prevent this? I thought most bbk setups require a freeflow filter... Maybe I should upjet to a 90 for the time being...

Sadly I can't order a new airbox 'til some time next month, but I found this airbox on Amazon:
http://www.amazon.com/Chinese-Scooter-Filter-Cleaner-Assembly/dp/B008ZX2NL8/ref=sr_1_1?ie=UTF8&qid=1369226180&sr=8-1&keywords=air+box+scooter

It advertises increased airflow for better performance, which might just be what I need since I have a 63cc and not a 49cc, however, I'm not sure.