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What main jet do you run on your 50cc 2T? Please mention your air/ exhaust/ CVT setup (roller weights) I'm running a 90 main jet now, with a de-restricted leo vince zx-r pipe, 6 gram rollers, and an aftermarket stage 6 air filter. I de-restricted the pipe yesterday. Yesterday the bike ran pretty good and I got it up to 46, though it was bogging lightly.. Now it bogs from quarter throttle, all the way up through mid throttle, quits moving in the mids, and sounds terrible.. I'm guessing it's due to the increased air supply, because when the air supply was restricted via the exhaust cone, it ran o.k. with the jet I was using.. Do I need to increase the size of my main jet to a 100 or so to increase my gas to air ratio? What are your thoughts?

Thank you!

Hi guys,

it's been 14 days and I still haven't received my exhaust, which is causing me to have to walk to work and back everyday, a two hour and twenty minute journey, one way. This is the third company that hasn't sent me my exhaust over the course of two months. I am giving it two more days and am cancelling the order. I had to call in to remind them to send it after they didn't get back to me for a week. It was supposedly sent on the 18th from California to North Carolina. Does anyone have experience with this company? http://www.spi-parts.com/

Thanks for your input..

Hey guys,

I've been getting into the mechanical aspect of powered bikes more and more these days. I started off with mountain bikes, but seeing as how I need to get around, I definitely need to understand performance issues. I recently purchased a new exhaust, (Leo Vince ZX-R) along with a main jet kit, Stage 6 air filter, BR8HIX iridium spark plug, and Polini race variator. My main jet is currently a 70, with stock settings and a normal air box. What main jet should I upgrade to, with the listed upgrades, to get me started? I know you are supposed to do spark plug color checks while tuning and all that, but I need a good size to start with, so that I can get to work in the meantime. I am looking for smooth and steady acceleration and a high top end for longer distances. If you have any tips about this topic, I would greatly appreciate your input.

Thanks, RJ

P.S. - The main jet sizes I have to work with, include 82, 85, 87, 90, 92, and 95

This is the stock exhaust. I chose to cut all the bs off of it, remove the flat black, and polish it out. I'm taking it to get welded tomorrow, after removing the blind pipes, adding a new exit pipe, and sanding it down a bit. After welding is done, I will do fine sanding and buff this thing out. I did some light mods to the bike (Iridium spark plug, derestricted variator roller, and I'm still working out how to mod the stock CDI) and should get an extra 10 - 15 mph out of it.. I will post more pics as I progress..

RJ



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